asy 2.25 sources

git-svn-id: svn://tug.org/texlive/trunk@33565 c570f23f-e606-0410-a88d-b1316a301751

15 files changed, 471 insertions, 12284 deletions

diff --git a/Build/source/utils/asymptote/doc/CAD.pdf b/Build/source/utils/asymptote/doc/CAD.pdf
deleted file mode 100644
index 2fcce4251e6..00000000000
--- a/Build/source/utils/asymptote/doc/CAD.pdf
+++ /dev/null
diff --git a/Build/source/utils/asymptote/doc/FAQ/asy-faq.bfnn b/Build/source/utils/asymptote/doc/FAQ/asy-faq.bfnn
index 26fcd14b628..21fb57233f0 100644
--- a/Build/source/utils/asymptote/doc/FAQ/asy-faq.bfnn
+++ b/Build/source/utils/asymptote/doc/FAQ/asy-faq.bfnn
@@ -421,7 +421,7 @@ size argument. If you want to do this globally, you can override the
 pen-dependent arrowsize function like this:
  
 \verbatim
-arrowsize=new real(pen p=currentpen) {return 2mm;};
+DefaultHead.size=new real(pen p=currentpen) {return 2mm;};
 \endverbatim
  
 \question 26jun:arrowhead Can I create other arrowhead styles?
diff --git a/Build/source/utils/asymptote/doc/FAQ/asy-faq.info b/Build/source/utils/asymptote/doc/FAQ/asy-faq.info
deleted file mode 100644
index aec3cabfcd0..00000000000
--- a/Build/source/utils/asymptote/doc/FAQ/asy-faq.info
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@@ -1,1671 +0,0 @@
-Info file: asy-faq.info,    -*-Text-*-
-produced by bfnnconv.pl from the Bizarre Format With No Name.
-
-INFO-DIR-SECTION Languages
-START-INFO-DIR-ENTRY
-* asymptote FAQ: (asy-faq).    Asymptote Frequently Asked Questions.
-END-INFO-DIR-ENTRY
-
-
-File: asy-faq.info, Node: Top, Next: Question 1.1, Up: (dir)
-
-            ASYMPTOTE FREQUENTLY ASKED QUESTIONS
-                            20 May 2013
-                          
-This is the list of Frequently Asked Questions about Asymptote (asy).
-
-Index
-
-* Menu:
-* Section 1::       About Asymptote
-* Section 2::       Questions about installation and setup
-* Section 3::       Questions about paths
-* Section 4::       Questions about labels
-* Section 5::       Questions about arrows
-* Section 6::       Questions about 2D graphs
-* Section 7::       Questions about programming
-* Section 8::       Questions about differences between Asymptote and
-                    MetaPost
-* Section 9::       Questions about output
-
-Section 1, About Asymptote
-* Question 1.1::    What is Asymptote?
-* Question 1.2::    How do I obtain Asymptote?
-* Question 1.3::    Where can I ask questions about Asymptote?
-* Question 1.4::    Why was the name Asymptote chosen?
-* Question 1.5::    In the internal Asymptote source code, what does the
-                    name camp refer to?
-
-Section 2, Questions about installation and setup
-* Question 2.1::    Is it possible to install Asymptote on Mac OS X?
-* Question 2.2::    Why do I get the error Bad CPU type in executable on
-                    installing Asymptote from the MAC OS binary?
-* Question 2.3::    What do I do if I get the error: Error: pdfetex (file
-                    pdftex.cfg): cannot open config file...texinfo.tex
-                    appears to be broken?
-* Question 2.4::    What do I do if I get the error: ! Undefined control
-                    sequence. l.6 @copying?
-* Question 2.5::    Is it possible to integrate Asymptote into LaTeX?
-* Question 2.6::    Is it possible to integrate Asymptote into latex or
-                    pdflatex?
-* Question 2.7::    Do I need the tkinter package to install an Asymptote
-                    rpm binary?
-* Question 2.8::    What does the path %USERPROFILE%\.asy\config.asy mean?
-* Question 2.9::    Why do I get the error "string not terminated" when I
-                    try to set settings.dir="C:\asymptote\";?
-* Question 2.10::   How do I change environment variables in Microsoft
-                    Windows, for example, in order to change the default
-                    PostScript viewer?
-* Question 2.11::   Under Microsoft Windows XP, why do I get an error like
-                    "Invalid Parameter - 432x432"?
-* Question 2.12::   Why does Asymptote freeze upon trying to draw a label
-                    with my MikTex installation under Microsoft Windows?
-
-Section 3, Questions about paths
-* Question 3.1::    Why do I get a syntax error message when I specify an
-                    integer value for the path tension?
-* Question 3.2::    Shouldn't dots always be the same size?
-
-Section 4, Questions about labels
-* Question 4.1::    How do I get Greek letters like omega to show up in my
-                    labels?
-* Question 4.2::    Can Asymptote use matrices as labels?
-* Question 4.3::    How do I tell Asymptote to load a particular LaTeX
-                    package, like mathptmx?
-* Question 4.4::    How can I use international fonts in Asymptote labels?
-* Question 4.5::    How can I use Fourier fonts?
-* Question 4.6::    Is there any way to change the default appearance of
-                    the decimal separator, using a comma instead of a dot?
-* Question 4.7::    How can I get a rotated label with the filled box
-                    rotated as well so that it fits the text?
-* Question 4.8::    How can I rotate labels in a 3D figure?
-* Question 4.9::    How can I draw some squares and circles of a fixed
-                    size and put a label in the middle of them?
-* Question 4.10::   The binary operator * can be used to scale the color
-                    of a pen by a real number. Does this scaling factor
-                    have to be less than 1?
-* Question 4.11::   Why is the space after the comma decimal separator in
-                    my locale so large?
-* Question 4.12::   How can I prevent
-                    texpreamble("\usepackage[pdftex]{hyperref}") from
-                    changing the page size?
-
-Section 5, Questions about arrows
-* Question 5.1::    How do I draw two arrows at arbitrary positions along
-                    a path?
-* Question 5.2::    How do I reverse the direction of an arrowhead?
-* Question 5.3::    How do I change the size of all arrows?
-* Question 5.4::    Can I create other arrowhead styles?
-
-Section 6, Questions about 2D graphs
-* Question 6.1::    How can I draw x axis ticks on the right side, with
-                    the tick labels on the left side (relative to the axis
-                    path)?
-* Question 6.2::    How can I reposition the x axis label to
-                    three-quarters along the axis length?
-* Question 6.3::    How can I move the x axis label down 10bp?
-* Question 6.4::    Can I use different pens for the axis, the axis label,
-                    and the tick labels?
-* Question 6.5::    How can I change the font type of the axes label?
-* Question 6.6::    How can I change the font type of the tick labels on
-                    an axis?
-* Question 6.7::    How can I prevent axes tick labels from rendering on
-                    top of each other?
-* Question 6.8::    How do I make the plot region of a graph, ignoring
-                    labels and legends, have a fixed size?
-* Question 6.9::    How can I plot a function f(x) within [0,1]x[0,2]
-                    without explicitly calculating the x values for which
-                    f(x) hits the boundary?
-* Question 6.10::   Is it possible to define customized palettes?
-* Question 6.11::   Is there an easy way to graph factorial functions
-                    nicely?
-* Question 6.12::   How do I indicate that a certain length should be
-                    exactly the size I prescribe with no rescaling, within
-                    a picture which has its own size?
-* Question 6.13::   How can I make the y axis display base-2 logarithmic
-                    values?
-* Question 6.14::   How can I align the x axes of two graphs on the same
-                    figure?
-* Question 6.15::   How can I change the direction of the y-axis, such
-                    that negatives values are on the upper y-axis?
-* Question 6.16::   How can I fill a path with a function that defines the
-                    color of each location?
-* Question 6.17::   Is there a way to draw a function that is not
-                    explicitly given, such as (y - 2)^2 = x - 1 ?
-* Question 6.18::   Is it possible to reverse or stretch an axis?
-* Question 6.19::   Why can't I use the UnFill option to draw graphs with
-                    empty markers?
-* Question 6.20::   How can I force several images to use the same palette
-                    range (e.g. the entire 0-255 grayscale range)?
-
-Section 7, Questions about programming
-* Question 7.1::    Is Asymptote an interpreter or a compiler?
-* Question 7.2::    What is the difference between a frame and a picture?
-* Question 7.3::    What is the difference between a path and a guide?
-* Question 7.4::    What is a convenient way to declare and initialize an
-                    array of pictures?
-* Question 7.5::    Is there a way to define functions that act on arrays
-                    in general (i.e. work for arrays of any type)?
-* Question 7.6::    Is there any way to declare structures ahead of their
-                    definition, e.g. where struct A performs some
-                    operation on struct B, but B contains an A member?
-* Question 7.7::    Where are static variables in for loops allocated?
-* Question 7.8::    Is there a debugger for asy?
-* Question 7.9::    Do you accept patches for Asymptote?
-
-Section 8, Questions about differences between Asymptote and
-                    MetaPost
-* Question 8.1::    What is the equivalent of the MetaPost c[a,b]
-                    interpolation operator?
-* Question 8.2::    How does picture scaling differ in Asymptote and
-                    MetaPost?
-* Question 8.3::    How can I avoid automatic scaling of a picture?
-* Question 8.4::    What is the equivalent of MetaPost ... command?
-* Question 8.5::    What is the equivalent of the MetaPost pickup command?
-* Question 8.6::    What is the equivalent of the MetaPost whatever
-                    command?
-* Question 8.7::    What is the equivalent for the MetaPost command for
-                    lray - horiz*v - verti*u = whatever*(LightSource - R),
-                    a system of three linear equations for three unknowns:
-                    horiz, verti, whatever?
-* Question 8.8::    In MetaPost, it is possible to have a drawing remain
-                    the same size in different pictures by defining a unit
-                    u and explicitly multiply all the coordinates by u. Is
-                    there a better way to do this in Asymptote?
-* Question 8.9::    In MetaPost, one could produce tiling pictures by
-                    generating a picture, and then clipping the picture to
-                    a rectangle of fixed dimensions around the center of
-                    the picture. How is that done in Asymptote?
-
-Section 9, Questions about output
-* Question 9.1::    How can I disable automatic invocation of the PS
-                    viewer after an asy file is done processing?
-* Question 9.2::    How do I output jpeg images?
-* Question 9.3::    Can I embed bitmaps (photos) into my drawings and
-                    position and scale them?
-* Question 9.4::    Does Asymptote support direct PDF output?
-* Question 9.5::    How to I produce large pictures of high quality in
-                    raster format (e.g. png, giff etc).
-* Question 9.6::    Is it possible to produce multi-page documents with
-                    asymptote?
-
-
-
-File: asy-faq.info, Node: Section 1, Next: Section 2, Previous: Top, Up: Top
-
-About Asymptote
-
-* Menu:
-* Question 1.1::    What is Asymptote?
-* Question 1.2::    How do I obtain Asymptote?
-* Question 1.3::    Where can I ask questions about Asymptote?
-* Question 1.4::    Why was the name Asymptote chosen?
-* Question 1.5::    In the internal Asymptote source code, what does the
-                    name camp refer to?
-
-
-
-File: asy-faq.info, Node: Question 1.1, Next: Question 1.2, Previous: Top, Up: Section 1
-
-Question 1.1.  What is Asymptote?
-
-Asymptote is a vector graphics language designed for technical graphics,
-inspired by MetaPost but with IEEE floating-point numerics, native
-three-dimensional graphics, Grayscale/RGB/CMYK colourspaces, and a
-C++-like syntax. Unlike MetaPost, it natively supports multiple-segment
-paths (and hence regions other than simply connected ones), tiling
-patterns, Gouraud  shading, tensor patch shading, and PostScript images.
-
-
-File: asy-faq.info, Node: Question 1.2, Next: Question 1.3, Previous: Question 1.1, Up: Section 1
-
-Question 1.2.  How do I obtain Asymptote?
-
-Binary releases are available for Linux, MacOS X, and Microsoft Windows
-platforms, in addition to full source code, from the website
-http://asymptote.sourceforge.net/.  Many Linux distributions (such as
-RedHat and Debian) now include an Asymptote package (check your
-distribution's documentation for further information about this).
-
-
-File: asy-faq.info, Node: Question 1.3, Next: Question 1.4, Previous: Question 1.2, Up: Section 1
-
-Question 1.3.  Where can I ask questions about Asymptote?
-
-If you have a question, please try to find an answer in this FAQ, in the
-extensive Asymptote documentation at
-http://asymptote.sourceforge.net/doc/, or search the forum:
-http://sourceforge.net/forum/forum.php?forum_id=409349.
-
-
-File: asy-faq.info, Node: Question 1.4, Next: Question 1.5, Previous: Question 1.3, Up: Section 1
-
-Question 1.4.  Why was the name Asymptote chosen?
-
-Well, it isn't the perfect graphics package, but we do think it is getting
-there asymptotically...
-
-
-File: asy-faq.info, Node: Question 1.5, Next: Question 2.1, Previous: Question 1.4, Up: Section 1
-
-Question 1.5.  In the internal Asymptote source code, what does the name camp refer to?
-
-That was our original tentative name for this project, which stood for
-"C's Answer to MetaPost" (the language that inspired Asymptote).  However,
-we eventually decided that the name Asymptote better emphasizes the
-mathematical and graphical nature of this language.
-
-
-File: asy-faq.info, Node: Section 2, Next: Section 3, Previous: Section 1, Up: Top
-
-Questions about installation and setup
-
-* Menu:
-* Question 2.1::    Is it possible to install Asymptote on Mac OS X?
-* Question 2.2::    Why do I get the error Bad CPU type in executable on
-                    installing Asymptote from the MAC OS binary?
-* Question 2.3::    What do I do if I get the error: Error: pdfetex (file
-                    pdftex.cfg): cannot open config file...texinfo.tex
-                    appears to be broken?
-* Question 2.4::    What do I do if I get the error: ! Undefined control
-                    sequence. l.6 @copying?
-* Question 2.5::    Is it possible to integrate Asymptote into LaTeX?
-* Question 2.6::    Is it possible to integrate Asymptote into latex or
-                    pdflatex?
-* Question 2.7::    Do I need the tkinter package to install an Asymptote
-                    rpm binary?
-* Question 2.8::    What does the path %USERPROFILE%\.asy\config.asy mean?
-* Question 2.9::    Why do I get the error "string not terminated" when I
-                    try to set settings.dir="C:\asymptote\";?
-* Question 2.10::   How do I change environment variables in Microsoft
-                    Windows, for example, in order to change the default
-                    PostScript viewer?
-* Question 2.11::   Under Microsoft Windows XP, why do I get an error like
-                    "Invalid Parameter - 432x432"?
-* Question 2.12::   Why does Asymptote freeze upon trying to draw a label
-                    with my MikTex installation under Microsoft Windows?
-
-
-
-File: asy-faq.info, Node: Question 2.1, Next: Question 2.2, Previous: Question 1.5, Up: Section 2
-
-Question 2.1.  Is it possible to install Asymptote on Mac OS X?
-
-It is easy to compile Asymptote directly from the source code at
-http://sourceforge.net/project/showfiles.php?group_id=120000 We recommend
-first upgrading to the latest GNU readline library, unless you don't care
-about interactive readline support (in which case configure will
-automatically detect and disable obsolete versions of the readline
-library).  Marius Schamschula also maintains a binary package for various
-MacOS X platforms
-http://www.hmug.org/pub/MacOS_X/X/Applications/Publishing/asymptote.
-
-
-File: asy-faq.info, Node: Question 2.2, Next: Question 2.3, Previous: Question 2.1, Up: Section 2
-
-Question 2.2.  Why do I get the error Bad CPU type in executable on installing Asymptote from the MAC OS binary?
-
-This means either that you have a binary distribution for another MAC
-architecture, or (according to Marius Schamschula) that you may have a
-missing library. The simplest solution is to compile Asymptote directly
-from the official source:
-http://sourceforge.net/project/showfiles.php?group_id=120000.
-
-
-File: asy-faq.info, Node: Question 2.3, Next: Question 2.4, Previous: Question 2.2, Up: Section 2
-
-Question 2.3.  What do I do if I get the error: Error: pdfetex (file pdftex.cfg): cannot open config file...texinfo.tex appears to be broken?
-
-Simply put http://asymptote.sourceforge.net/asymptote.pdf in the directory
-doc and repeat the command make all.  Or, if you don't want to build a
-local copy of the documentation, simply proceed with make install-asy.
-
-
-File: asy-faq.info, Node: Question 2.4, Next: Question 2.5, Previous: Question 2.3, Up: Section 2
-
-Question 2.4.  What do I do if I get the error: ! Undefined control sequence. l.6 @copying?
-
-Either upgrade your texinfo package or follow one of the easy work arounds
-in *Note Question 2.3:: `What do I do if I get the error: Error: pdfetex
-(file pdftex.cfg): cannot open config file...texinfo.tex appears to be
-broken?'.
-
-
-File: asy-faq.info, Node: Question 2.5, Next: Question 2.6, Previous: Question 2.4, Up: Section 2
-
-Question 2.5.  Is it possible to integrate Asymptote into LaTeX?
-
-Yes, see the example latexusage.tex. Dario Teixeira has also written a
-detailed guide on the topic. You can download it from
-http://dario.dse.nl/projects/asylatex/.
-
-Philippe Ivaldi has contributed an Asymptote mode for Emacs users
-http://asymptote.sourceforge.net/doc/Editing-modes.html, which includes a
-lasy-mode that allows one to compile and view the output of one
-\begin{asy}...\end{asy} section at a time.
-
-
-File: asy-faq.info, Node: Question 2.6, Next: Question 2.7, Previous: Question 2.5, Up: Section 2
-
-Question 2.6.  Is it possible to integrate Asymptote into latex or pdflatex?
-
-Yes, as of version 1.14, Asymptote supports latex and pdflatex (both in
-EPS/PDF and inline mode), as illustrated by the example latexusage.tex:
-
-pdflatex latexusage
-asy latexusage
-pdflatex latexusage
-
-File: asy-faq.info, Node: Question 2.7, Next: Question 2.8, Previous: Question 2.6, Up: Section 2
-
-Question 2.7.  Do I need the tkinter package to install an Asymptote rpm binary?
-
-No, you don't need tkinter unless you want to try out the GUI xasy. Try
-
-rpm -Uvh --nodeps asymptote-x.xx-1.i386.rpm
-where x.xx represents the version number.
-
-
-File: asy-faq.info, Node: Question 2.8, Next: Question 2.9, Previous: Question 2.7, Up: Section 2
-
-Question 2.8.  What does the path %USERPROFILE%\.asy\config.asy mean?
-
-That is the way that Microsoft Windows refers to the user profile
-directory.  There's nothing really to understand here, just put your
-configuration commands in the file config.asy in a new folder
-%USERPROFILE%\.asy.
-
-
-File: asy-faq.info, Node: Question 2.9, Next: Question 2.10, Previous: Question 2.8, Up: Section 2
-
-Question 2.9.  Why do I get the error "string not terminated" when I try to set settings.dir="C:\asymptote\";?
-
-The backslash is an escape character here, so \" is interpreted as a
-verbatim quotation mark, leaving the string without a terminating
-quotation mark. Fortunately, this is the only escaped character in
-double-quoted strings. A final backslash isn't needed here anyway, but
-should you really want one somewhere, you can say:
-settings.dir="C:\asymptote"+'\\';.
-
-
-File: asy-faq.info, Node: Question 2.10, Next: Question 2.11, Previous: Question 2.9, Up: Section 2
-
-Question 2.10.  How do I change environment variables in Microsoft Windows, for example, in order to change the default PostScript viewer?
-
-While it is easier to set the corresponding Asymptote configuration
-variable in your config.asy file, here is the procedure for changing
-Microsoft Windows environment variables:
-
-Click on the [Start] button
-
-* RIGHT-click on 'My Computer'
-
-* Choose 'Properties' from the popup menu
-
-* Click the 'Advanced' tab
-
-* Click the 'Environment Variables' button.
-
-
-File: asy-faq.info, Node: Question 2.11, Next: Question 2.12, Previous: Question 2.10, Up: Section 2
-
-Question 2.11.  Under Microsoft Windows XP, why do I get an error like "Invalid Parameter - 432x432"?
-
-This means that ImageMagick wasn't properly installed and you are using
-the MSDOS convert program rather than the ImageMagick one. Or you may have
-installed ImageMagick but ran Asymptote from an existing MSDOS window.  In
-that case, simply open a new window and try again. If that doesn't work,
-check that
-
-convert --version 
-returns something like
-
-Version: ImageMagick 6.2.8 06/27/06 Q16 http://www.imagemagick.org
-
-File: asy-faq.info, Node: Question 2.12, Next: Question 3.1, Previous: Question 2.11, Up: Section 2
-
-Question 2.12.  Why does Asymptote freeze upon trying to draw a label with my MikTex installation under Microsoft Windows?
-
-Likely, this means that latex and dvips are not in your default path.  Try
-adding the appropriate paths in your config.asy file,  for example:
-
-import settings;
-latex="C:\Program Files\MiKTeX 2.7\miktex\bin\latex.exe";
-dvips="C:\Program Files\MiKTeX 2.7\miktex\bin\dvips.exe";
-
-File: asy-faq.info, Node: Section 3, Next: Section 4, Previous: Section 2, Up: Top
-
-Questions about paths
-
-* Menu:
-* Question 3.1::    Why do I get a syntax error message when I specify an
-                    integer value for the path tension?
-* Question 3.2::    Shouldn't dots always be the same size?
-
-
-
-File: asy-faq.info, Node: Question 3.1, Next: Question 3.2, Previous: Question 2.12, Up: Section 3
-
-Question 3.1.  Why do I get a syntax error message when I specify an integer value for the path tension?
-
-What is happening here is that
-
-draw((0,0)..tension 2..(0,50)..(100,100));
-is read as
-
-draw((0,0)..tension 2. .(0,50)..(100,100));
-So the first . after the two is treated as a decimal point.  Just put a
-space after the integer tension value:
-
-draw((0,0)..tension 2 ..(0,50)..(100,100));
-
-File: asy-faq.info, Node: Question 3.2, Next: Question 4.1, Previous: Question 3.1, Up: Section 3
-
-Question 3.2.  Shouldn't dots always be the same size?
-
-From the documentation:
-
-"The dot command defined in the module plain draws a dot having a diameter
-equal to an explicit pen linewidth or the default linewidth magnified by
-dotfactor (6 by default)."
-
-Thus, when you use the default pen, the dot will have size 6*linewidth,
-but when you give a pen with an explicit width specified, you will  have a
-dot of size linewidth. If you want the first case to behave like the
-second, you may set dotfactor=1.
-
-
-File: asy-faq.info, Node: Section 4, Next: Section 5, Previous: Section 3, Up: Top
-
-Questions about labels
-
-* Menu:
-* Question 4.1::    How do I get Greek letters like omega to show up in my
-                    labels?
-* Question 4.2::    Can Asymptote use matrices as labels?
-* Question 4.3::    How do I tell Asymptote to load a particular LaTeX
-                    package, like mathptmx?
-* Question 4.4::    How can I use international fonts in Asymptote labels?
-* Question 4.5::    How can I use Fourier fonts?
-* Question 4.6::    Is there any way to change the default appearance of
-                    the decimal separator, using a comma instead of a dot?
-* Question 4.7::    How can I get a rotated label with the filled box
-                    rotated as well so that it fits the text?
-* Question 4.8::    How can I rotate labels in a 3D figure?
-* Question 4.9::    How can I draw some squares and circles of a fixed
-                    size and put a label in the middle of them?
-* Question 4.10::   The binary operator * can be used to scale the color
-                    of a pen by a real number. Does this scaling factor
-                    have to be less than 1?
-* Question 4.11::   Why is the space after the comma decimal separator in
-                    my locale so large?
-* Question 4.12::   How can I prevent
-                    texpreamble("\usepackage[pdftex]{hyperref}") from
-                    changing the page size?
-
-
-
-File: asy-faq.info, Node: Question 4.1, Next: Question 4.2, Previous: Question 3.2, Up: Section 4
-
-Question 4.1.  How do I get Greek letters like omega to show up in my labels?
-
-In (La)TeX, Greek letters can be obtained in math mode by prepending a
-backslash to the letter name. So for a omega symbol, use "$\omega$".
-Everything between the dollar signs is considered to be a math formula.
-Uppercase Greek letters can be used by capitalizing the first letter of
-the name:
-
-label("$\omega$",(0,0));
-label("$\Omega$",(20,0));
-
-File: asy-faq.info, Node: Question 4.2, Next: Question 4.3, Previous: Question 4.1, Up: Section 4
-
-Question 4.2.  Can Asymptote use matrices as labels?
-
-Yes:
-usepackage("amsmath");
-label("$\begin{matrix} 1 & 2 \\\ 1 & 1 \end{matrix}$",(0,0));
-
-File: asy-faq.info, Node: Question 4.3, Next: Question 4.4, Previous: Question 4.2, Up: Section 4
-
-Question 4.3.  How do I tell Asymptote to load a particular LaTeX package, like mathptmx?
-
-Put
-
-usepackage("mathptmx");
-at the beginning of your file. Note: to enable the Adobe Times Roman font
-for text, you will also need to say:
-defaultpen(TimesRoman());
-
-File: asy-faq.info, Node: Question 4.4, Next: Question 4.5, Previous: Question 4.3, Up: Section 4
-
-Question 4.4.  How can I use international fonts in Asymptote labels?
-
-See http://asymptote.sourceforge.net/doc/unicode.html.
-
-
-File: asy-faq.info, Node: Question 4.5, Next: Question 4.6, Previous: Question 4.4, Up: Section 4
-
-Question 4.5.  How can I use Fourier fonts?
-
-usepackage("fourier");
-defaultpen(font("T1","fut\textfamilyextension","m","n"));
-
-File: asy-faq.info, Node: Question 4.6, Next: Question 4.7, Previous: Question 4.5, Up: Section 4
-
-Question 4.6.  Is there any way to change the default appearance of the decimal separator, using a comma instead of a dot?
-
-Just set your locale appropriately:
-
-locale("it_IT");
-usepackage("icomma");
-label(format(0.5));
-
-File: asy-faq.info, Node: Question 4.7, Next: Question 4.8, Previous: Question 4.6, Up: Section 4
-
-Question 4.7.  How can I get a rotated label with the filled box rotated as well so that it fits the text?
-
-frame f;
-label(f,"This is some text",white,Fill(blue));
-add(rotate(65)*f);
-
-File: asy-faq.info, Node: Question 4.8, Next: Question 4.9, Previous: Question 4.7, Up: Section 4
-
-Question 4.8.  How can I rotate labels in a 3D figure?
-
-You need to first project the triple to a pair like this:
-
-import three;
-size(100,100);
-
-draw(rotate(90,project(Z))*"A",O--X);
-
-File: asy-faq.info, Node: Question 4.9, Next: Question 4.10, Previous: Question 4.8, Up: Section 4
-
-Question 4.9.  How can I draw some squares and circles of a fixed size and put a label in the middle of them?
-
-Fixed-size objects should be drawn on a separate picture and then added to
-currentpicture. Here is one way (see also
-http://asymptote.sourceforge.net/gallery/subpictures.asy and
-http://asymptote.sourceforge.net/gallery/mosquito.asy):
-
-real u=2cm;
- 
-picture square;
-draw(square,scale(u)*shift(-0.5,-0.5)*unitsquare);
- 
-picture circle;
-draw(circle,scale(0.5u)*unitcircle);
- 
-void add(picture pic=currentpicture, Label L, picture object, pair z) { 
-add(pic,object,z);
-label(pic,L,z);
-} 
- 
-add("square",square,(0,0));
-add("circle",circle,(5cm,0));
-
-File: asy-faq.info, Node: Question 4.10, Next: Question 4.11, Previous: Question 4.9, Up: Section 4
-
-Question 4.10.  The binary operator * can be used to scale the color of a pen by a real number. Does this scaling factor have to be less than 1?
-
-The scaling factor can be greater than 1. But keep in mind that the rgb
-color  components saturate at 1.
-
-Try
-write(cyan); write(0.8*cyan); write(1.5*cyan);
-and you will quickly see what is going on.
-
-To get a lighter cyan you can say white+cyan,  which yields rgb(0.5,1,1).
-If you want something even lighter specify the  rgb colors directly,  for
-example, rgb(0.9,1,1).
-
-Alternatively, work in cmyk colour space, which is nicer in that it
-handles  saturation separately from hue:
-
-0.1*Cyan is light and 0.9*Cyan is dark.  You can also say 0.1*cmyk(red).
-
-
-File: asy-faq.info, Node: Question 4.11, Next: Question 4.12, Previous: Question 4.10, Up: Section 4
-
-Question 4.11.  Why is the space after the comma decimal separator in my locale so large?
-
-LaTeX is treating the comma as punctuation and not as a decimal separator.
-The solution is to load the icomma package near the beginning of your
-file:
-usepackage("icomma");
-
-File: asy-faq.info, Node: Question 4.12, Next: Question 5.1, Previous: Question 4.11, Up: Section 4
-
-Question 4.12.  How can I prevent texpreamble("\usepackage[pdftex]{hyperref}") from changing the page size?
-
-texpreamble("\usepackage[pdftex,setpagesize=false]{hyperref}");
-
-File: asy-faq.info, Node: Section 5, Next: Section 6, Previous: Section 4, Up: Top
-
-Questions about arrows
-
-* Menu:
-* Question 5.1::    How do I draw two arrows at arbitrary positions along
-                    a path?
-* Question 5.2::    How do I reverse the direction of an arrowhead?
-* Question 5.3::    How do I change the size of all arrows?
-* Question 5.4::    Can I create other arrowhead styles?
-
-
-
-File: asy-faq.info, Node: Question 5.1, Next: Question 5.2, Previous: Question 4.12, Up: Section 5
-
-Question 5.1.  How do I draw two arrows at arbitrary positions along a path?
-
-Assuming that at least one of the arrowheads is to be filled, you can do
-this:
-
-size(200); 
-path g = (0,0)..(1,3)..(3,0); 
-draw(g,Arrow(Relative(0.9))); 
-add(arrow(g,invisible,FillDraw(black),Relative(0.5))); 
-add(arrow(reverse(g),invisible,FillDraw(white,black),Relative(0.9))); 
-If both of the arrowheads are to be drawn with filltype NoFill, one will
-need to create a specialized version of the arrow routine in
-plain_arrows.asy:
-
-void arrow(frame f, arrowhead arrowhead=DefaultHead,
-           path g, pen p=currentpen, real size=0,
-           real angle=arrowangle, filltype filltype=arrowhead.defaultfilltype,
-           position position=EndPoint, bool forwards=true,
-           margin margin=NoMargin, bool center=false);
-
-File: asy-faq.info, Node: Question 5.2, Next: Question 5.3, Previous: Question 5.1, Up: Section 5
-
-Question 5.2.  How do I reverse the direction of an arrowhead?
-
-Simply reverse the direction of the path.
-
-path g=((0,0)--(5cm,0));
-draw(reverse(g),Arrow(Relative(0.55)));
-
-File: asy-faq.info, Node: Question 5.3, Next: Question 5.4, Previous: Question 5.2, Up: Section 5
-
-Question 5.3.  How do I change the size of all arrows?
-
-To override the arrowsize you can give every Arrow drawing attribute a
-real size argument. If you want to do this globally, you can override the
-pen-dependent arrowsize function like this:
-
-arrowsize=new real(pen p=currentpen) {return 2mm;};
-
-File: asy-faq.info, Node: Question 5.4, Next: Question 6.1, Previous: Question 5.3, Up: Section 5
-
-Question 5.4.  Can I create other arrowhead styles?
-
-Yes, you can build custom arrowheads like this (see the predefined
-arrowhead styles in plain_arrows.asy for further examples):
-
-arrowhead DotHead;
-DotHead.head=new path(path g, position position=EndPoint, pen p=currentpen,
-                      real size=0, real angle=arrowangle) {
-  if(size == 0) size=DotHead.size(p);
-  bool relative=position.relative;
-  real position=position.position.x;
-  if(relative) position=reltime(g,position);
-  path r=subpath(g,position,0);
-  pair x=point(r,0);
-  real t=arctime(r,size);
-  pair y=point(r,t);
-  return circle(0.5(x+y),0.5size);
-};
-
-size(100);
-draw((0,0)..(1,1)..(2,0),Arrow(DotHead));
-dot((2,0),red);
-If you submit your alternate arrowheads to the Forum or the Patch
-Tracking System, we'll consider including them in a future release.
-
-
-File: asy-faq.info, Node: Section 6, Next: Section 7, Previous: Section 5, Up: Top
-
-Questions about 2D graphs
-
-* Menu:
-* Question 6.1::    How can I draw x axis ticks on the right side, with
-                    the tick labels on the left side (relative to the axis
-                    path)?
-* Question 6.2::    How can I reposition the x axis label to
-                    three-quarters along the axis length?
-* Question 6.3::    How can I move the x axis label down 10bp?
-* Question 6.4::    Can I use different pens for the axis, the axis label,
-                    and the tick labels?
-* Question 6.5::    How can I change the font type of the axes label?
-* Question 6.6::    How can I change the font type of the tick labels on
-                    an axis?
-* Question 6.7::    How can I prevent axes tick labels from rendering on
-                    top of each other?
-* Question 6.8::    How do I make the plot region of a graph, ignoring
-                    labels and legends, have a fixed size?
-* Question 6.9::    How can I plot a function f(x) within [0,1]x[0,2]
-                    without explicitly calculating the x values for which
-                    f(x) hits the boundary?
-* Question 6.10::   Is it possible to define customized palettes?
-* Question 6.11::   Is there an easy way to graph factorial functions
-                    nicely?
-* Question 6.12::   How do I indicate that a certain length should be
-                    exactly the size I prescribe with no rescaling, within
-                    a picture which has its own size?
-* Question 6.13::   How can I make the y axis display base-2 logarithmic
-                    values?
-* Question 6.14::   How can I align the x axes of two graphs on the same
-                    figure?
-* Question 6.15::   How can I change the direction of the y-axis, such
-                    that negatives values are on the upper y-axis?
-* Question 6.16::   How can I fill a path with a function that defines the
-                    color of each location?
-* Question 6.17::   Is there a way to draw a function that is not
-                    explicitly given, such as (y - 2)^2 = x - 1 ?
-* Question 6.18::   Is it possible to reverse or stretch an axis?
-* Question 6.19::   Why can't I use the UnFill option to draw graphs with
-                    empty markers?
-* Question 6.20::   How can I force several images to use the same palette
-                    range (e.g. the entire 0-255 grayscale range)?
-
-
-
-File: asy-faq.info, Node: Question 6.1, Next: Question 6.2, Previous: Question 5.4, Up: Section 6
-
-Question 6.1.  How can I draw x axis ticks on the right side, with the tick labels on the left side (relative to the axis path)?
-
-import graph;
-
-size(250,200,IgnoreAspect);
-
-draw(graph(exp,-1,1),red);
-
-xaxis("$x$",RightTicks(Label(align=left)));
-yaxis("$y$",RightTicks);
-
-File: asy-faq.info, Node: Question 6.2, Next: Question 6.3, Previous: Question 6.1, Up: Section 6
-
-Question 6.2.  How can I reposition the x axis label to three-quarters along the axis length?
-
-import graph;
-
-size(250,200,IgnoreAspect);
-
-draw(graph(exp,-1,1),red);
-
-xaxis(Label("$x$",0.75),LeftTicks);
-yaxis("$y$",RightTicks);
-
-File: asy-faq.info, Node: Question 6.3, Next: Question 6.4, Previous: Question 6.2, Up: Section 6
-
-Question 6.3.  How can I move the x axis label down 10bp?
-
-import graph;
-size(250,200,IgnoreAspect);
-
-draw(graph(exp,-1,1),red);
-
-xaxis(shift(0,-10)*"$x$",LeftTicks);
-yaxis("$y$",RightTicks);
-
-File: asy-faq.info, Node: Question 6.4, Next: Question 6.5, Previous: Question 6.3, Up: Section 6
-
-Question 6.4.  Can I use different pens for the axis, the axis label, and the tick labels?
-
-Yes:
-
-import graph;
-size(300,200,IgnoreAspect);
-
-xlimits(-50,50);
-ylimits(0,100);
-
-xaxis(Label("$x$",MidPoint,red),Bottom,blue,LeftTicks(green));
-yaxis("$y$",Left,RightTicks);
-
-File: asy-faq.info, Node: Question 6.5, Next: Question 6.6, Previous: Question 6.4, Up: Section 6
-
-Question 6.5.  How can I change the font type of the axes label?
-
-import graph;
-size(300,200,IgnoreAspect);
-
-xlimits(-50,50);
-ylimits(0,100);
-
-xaxis("x",Bottom,Courier("m","n"),LeftTicks);
-yaxis("$y$",Left,RightTicks);
-
-File: asy-faq.info, Node: Question 6.6, Next: Question 6.7, Previous: Question 6.5, Up: Section 6
-
-Question 6.6.  How can I change the font type of the tick labels on an axis?
-
-Tick labels are by default typeset in (TeX) math mode, so to use other
-fonts you need to override the default tick format:
-
-import graph;
-size(300,200,IgnoreAspect);
-
-xlimits(-50,50);
-ylimits(0,100);
-
-xaxis("$x$",Bottom,LeftTicks("%.4g",Courier("m","n")+fontsize(12)));
-yaxis("$y$",Left,RightTicks);
-
-File: asy-faq.info, Node: Question 6.7, Next: Question 6.8, Previous: Question 6.6, Up: Section 6
-
-Question 6.7.  How can I prevent axes tick labels from rendering on top of each other?
-
-Either:
-
-(i) give LeftTicks/RightTicks/Ticks the arguments beginlabel=false and/or
-endlabel=false;
-
-(ii) explicitly remove specific ticks and their labels (drawing them
-manually; see
-http://asymptote.svn.sourceforge.net/viewvc/asymptote/trunk/asymptote/base/graph.asy
-for the definition of NoZero):
-
-import graph;
-
-size(10cm);
-
-real f(real x) {return x^2;}
- 
-draw(graph(f,-2,2));
-
-xaxis(Ticks(NoZero));
-yaxis(Ticks(NoZero));
-
-label("$0$",(0,0),SW);
-(iii) explicitly remove specific tick labels and draw them manually (see
-http://asymptote.svn.sourceforge.net/viewvc/asymptote/trunk/asymptote/base/graph.asy
-for the definition of NoZeroFormat):
-
-import graph;
-
-size(10cm);
-
-real f(real x) {return x^2;}
- 
-draw(graph(f,-2,2));
-
-xaxis(Ticks(NoZeroFormat));
-yaxis(Ticks(NoZeroFormat));
-
-label("$0$",(0,0),SW);
-(iv) use the xasy GUI to move overlapping labels;
-
-(v) change the Label argument of LeftTicks, RightTicks, or Ticks to:
-
-Label(currentpen+overwrite(Move))
-Solution (v) will move labels that might otherwise overwrite a previous
-label. Other possible overwrite arguments are Allow (allows overlapping
-labels; the default), Suppress (an overlapping label will not be written
-at all), SuppressQuiet, and MoveQuiet. The last two achieve the same
-result as the non-quiet types, but will not notify you which labels are
-overlapping. See:  http://asymptote.sourceforge.net/doc/Pens.html.
-
-In the case of a user-specified tick array, you can change which labels
-get suppressed/moved by changing the order of array entries.
-
-
-File: asy-faq.info, Node: Question 6.8, Next: Question 6.9, Previous: Question 6.7, Up: Section 6
-
-Question 6.8.  How do I make the plot region of a graph, ignoring labels and legends, have a fixed size?
-
-Either:
-
-i) Specify an explicit unitsize, which overrides any call to size:
-unitsize(x=1cm,y=2cm);
-ii) Explicitly tell Asymptote to map the plot region to a specific size:
-import graph;
-real[] x={0,1,2,3};
-real[] y=x^2;
-draw(graph(x,y),red);
-xaxis("$x$",BottomTop,LeftTicks);
-yaxis("$y$",LeftRight,RightTicks);
-
-size(5cm,5cm,point(SW),point(NE));
-
-label("$f_\mathrm{T}$",point(N),2N);
-iii) Specify the points in user coordinates that should correspond to a
-given picture size:
-
-import graph;
-
-size(250,200,IgnoreAspect);
-
-draw(graph(exp,-1,1),red);
-
-xaxis("$x$",BottomTop,LeftTicks);
-yaxis("$y$",LeftRight,RightTicks);
-
-fixedscaling((-1.5,-0.5),(1.5,3.5));
-In this example, the user coordinate (-1.5,-0.5) will end up being the
-lower left corner of the figure and (1.5,3.5) will be the upper right
-corner. You can use this option to ensure multiple figures have the same
-scaling and same resulting figure size (just ensure the two coordinates
-given to fixedscaling() leaves room for any labels).
-
-See also http://asymptote.sourceforge.net/doc/Frames-and-pictures.html.
-
-
-File: asy-faq.info, Node: Question 6.9, Next: Question 6.10, Previous: Question 6.8, Up: Section 6
-
-Question 6.9.  How can I plot a function f(x) within [0,1]x[0,2] without explicitly calculating the x values for which f(x) hits the boundary?
-
-Call limits with the Crop option before drawing the graph:
-import graph;
-
-size(250,200,IgnoreAspect);
-
-draw(graph(exp,-1,1),red);
-
-limits((0,0),(1,2),Crop);
-
-xaxis("$x$",BottomTop,LeftTicks);
-yaxis("$y$",LeftRight,RightTicks);
-See also http://asymptote.sourceforge.net/doc/graph.html.
-
-
-File: asy-faq.info, Node: Question 6.10, Next: Question 6.11, Previous: Question 6.9, Up: Section 6
-
-Question 6.10.  Is it possible to define customized palettes?
-
-Yes, you may generate your own pen[] array. For example:
-
-int NColors=32768;
-pen[] MyPalette=new pen[NColors];
-real step=1/(NColors-1.0);
-// Start at black: rgb(0,0,0) 
-// End at yellow: rgb(1,1,0) 
-for(int i=0; i < NColors; ++i) { 
-  real rgval=i*step;
-  MyPalette[i]=rgb(rgval,rgval,0.0);
-} 
-
-File: asy-faq.info, Node: Question 6.11, Next: Question 6.12, Previous: Question 6.10, Up: Section 6
-
-Question 6.11.  Is there an easy way to graph factorial functions nicely?
-
-The example below shows a continuous function and two methods for placing
-markers at integer values of x:
-
-import graph;
- 
-size(200,200,IgnoreAspect);
- 
-real factorial(real t) {return gamma(t+1);} 
- 
-scale(Linear,Log);
- 
-// Graph the factorial function.
-draw(graph(factorial,0,10));
- 
-// Method 1: Draw nodes, but hide line
-pair F(int t) {return (t,factorial(t));} 
-// Graph of factorial function from 0 to 10
-pair[] z=sequence(F,11);
-draw(graph(z),invisible,marker(scale(0.8mm)*unitcircle,blue,Fill));
- 
-// Method 2: Nongraphing routines require explicit scaling:
-pair dotloc(int t) {return Scale(F(t));} 
-pair[] dotlocs=sequence(dotloc,11);
-dot(dotlocs);
- 
-xaxis("$x$",BottomTop,LeftTicks);
-yaxis("$y$",LeftRight,RightTicks);
-
-File: asy-faq.info, Node: Question 6.12, Next: Question 6.13, Previous: Question 6.11, Up: Section 6
-
-Question 6.12.  How do I indicate that a certain length should be exactly the size I prescribe with no rescaling, within a picture which has its own size?
-
-Here's an easy way to do this.
-
-size(12cm,0);
- 
-void distance(picture pic=currentpicture, pair A, pair B, Label L="", real n=0,
-              pen p=currentpen) 
-{
-  real d=3mm;
-  path g=A--B;
-  transform T=shift(-n*d*unit(B-A)*I);
-  pic.add(new void(frame f, transform t) {
-    picture opic;
-    path G=T*t*g;
-    draw(opic,Label(L,Center,UnFill(1)),G,p,Arrows(NoFill),Bars,PenMargins);
-    add(f,opic.fit());
-  });
-  pic.addBox(min(g),max(g),T*min(p),T*max(p));
-} 
- 
-pair A=(0,0), B=(3,3);
- 
-dot(A);
-dot(B);
- 
-distance(A,B,"$\ell$",1);
-
-File: asy-faq.info, Node: Question 6.13, Next: Question 6.14, Previous: Question 6.12, Up: Section 6
-
-Question 6.13.  How can I make the y axis display base-2 logarithmic values?
-
-See the example http://asymptote.sourceforge.net/gallery/2D
-graphs/log2graph.asy.
-
-
-File: asy-faq.info, Node: Question 6.14, Next: Question 6.15, Previous: Question 6.13, Up: Section 6
-
-Question 6.14.  How can I align the x axes of two graphs on the same figure?
-
-An easy way to do this, if the axes to be aligned have the same scaling
-and size, is illustrated in the example
-http://asymptote.sourceforge.net/gallery/2D graphs/alignedaxis.asy.
-
-Here is a more general solution to the problem of aligning two arbitrary
-axes.  One fits the second picture to a frame based on the horizontal
-scaling for the first picture:
-
-import graph;
-
-real width=15cm;
-real aspect=0.3;
-
-picture pic1,pic2;
-
-size(pic1,width,aspect*width,IgnoreAspect);
-size(pic2,width,aspect*width,IgnoreAspect);
-
-scale(pic1,false);
-scale(pic2,false);
-
-real xmin1=6;
-real xmax1=9;
-real xmin2=8;
-real xmax2=16;
-
-real a1=1;
-real a2=0.001;
-
-real f1(real x) {return a1*sin(x/2*pi);}
-real f2(real x) {return a2*sin(x/4*pi);}
-
-draw(pic1,graph(pic1,f1,xmin1,xmax1));
-draw(pic2,graph(pic2,f2,xmin2,xmax2));
-
-xaxis(pic1,Bottom,LeftTicks());
-yaxis(pic1,"$f_1(x)$",Left,RightTicks);
-
-xaxis(pic2,"$x$",Bottom,LeftTicks(Step=4));
-yaxis(pic2,"$f_2(x)$",Left,RightTicks);
-
-yequals(pic1,0,Dotted);
-yequals(pic2,0,Dotted);
-
-pair min1=point(pic1,SW);
-pair max1=point(pic1,NE);
-
-pair min2=point(pic2,SW);
-pair max2=point(pic2,NE);
-
-real scale=(max1.x-min1.x)/(max2.x-min2.x);
-real shift=min1.x/scale-min2.x;
-
-transform t1=pic1.calculateTransform();
-transform t2=pic2.calculateTransform();
-transform T=xscale(scale*t1.xx)*yscale(t2.yy);
-
-add(pic1.fit());
-real height=truepoint(N,user=false).y-truepoint(S,user=false).y;
-add(shift(0,-height)*(shift(shift)*pic2).fit(T));
-
-File: asy-faq.info, Node: Question 6.15, Next: Question 6.16, Previous: Question 6.14, Up: Section 6
-
-Question 6.15.  How can I change the direction of the y-axis, such that negatives values are on the upper y-axis?
-
-Here is a simple example (see also the example
-http://asymptote.sourceforge.net/gallery/2D graphs/diatom.asy or the
-discussion of Linear(-1) in the documentation):
-
-import graph;
-size(250,200,IgnoreAspect);
-
-scale(Linear,Linear(-1));
-
-draw(graph(log,0.1,10),red);
-
-xaxis("$x$",LeftTicks);
-yaxis("$y$",RightTicks);
-
-File: asy-faq.info, Node: Question 6.16, Next: Question 6.17, Previous: Question 6.15, Up: Section 6
-
-Question 6.16.  How can I fill a path with a function that defines the color of each location?
-
-Use functionshade with a PDF tex engine, as illustrated by the example
-{functionshading.asy}.
-
-If you want to produce PostScript output, an approximate solution for now
-would be to superimpose a fine grid and specify colors to  latticeshade
-that depend on position as a single pen[][] lattice. Alternatively, it may
-be more efficient to use tensorshade}.
-
-
-File: asy-faq.info, Node: Question 6.17, Next: Question 6.18, Previous: Question 6.16, Up: Section 6
-
-Question 6.17.  Is there a way to draw a function that is not explicitly given, such as (y - 2)^2 = x - 1 ?
-
-Yes, use the parametric form
-
-y=t 
-x=(t-2)^2+1 
-See the example http://asymptote.sourceforge.net/gallery/2D
-graphs/parametricgraph.asy.
-
-
-File: asy-faq.info, Node: Question 6.18, Next: Question 6.19, Previous: Question 6.17, Up: Section 6
-
-Question 6.18.  Is it possible to reverse or stretch an axis?
-
-The real scaling argument to Linear is used to stretch (or reverse) the
-axis.  To see the effect of axis stretching, be sure not to specify
-IgnoreAspect in  the picture size command.
-
-A secondary axis has the same length as the primary axis, so stretching
-cannot  have any effect. But one can still reverse the axis, with
-Linear(-1).
-
-
-File: asy-faq.info, Node: Question 6.19, Next: Question 6.20, Previous: Question 6.18, Up: Section 6
-
-Question 6.19.  Why can't I use the UnFill option to draw graphs with empty markers?
-
-UnFill won't work here because it only affects the local frame the markers
-are initially drawn on, before being added to currentpicture.  Here is a
-way of achieving the desired effect (assuming a white background):
-
-import graph;
-size(10cm,0);
-pair[] z={(0,0),(0.5,0.5),(1,1)};
-path g=graph(z);
- 
-draw(shift(0,.5)*g,marker(scale(5)*unitcircle,FillDraw(white)));
- 
-xaxis(BottomTop,LeftTicks);
-yaxis(LeftRight,RightTicks);
-
-File: asy-faq.info, Node: Question 6.20, Next: Question 7.1, Previous: Question 6.19, Up: Section 6
-
-Question 6.20.  How can I force several images to use the same palette range (e.g. the entire 0-255 grayscale range)?
-
-The palette color space corresponds to a range of values specified by the
-argument range, which can be Full, Automatic or an explicit range
-Range(pair min, pair max). Here Full} specifies a range varying from the
-minimum to maximum values of the function over the sampling interval,
-while Automatic selects "nice" limits.
-
-
-File: asy-faq.info, Node: Section 7, Next: Section 8, Previous: Section 6, Up: Top
-
-Questions about programming
-
-* Menu:
-* Question 7.1::    Is Asymptote an interpreter or a compiler?
-* Question 7.2::    What is the difference between a frame and a picture?
-* Question 7.3::    What is the difference between a path and a guide?
-* Question 7.4::    What is a convenient way to declare and initialize an
-                    array of pictures?
-* Question 7.5::    Is there a way to define functions that act on arrays
-                    in general (i.e. work for arrays of any type)?
-* Question 7.6::    Is there any way to declare structures ahead of their
-                    definition, e.g. where struct A performs some
-                    operation on struct B, but B contains an A member?
-* Question 7.7::    Where are static variables in for loops allocated?
-* Question 7.8::    Is there a debugger for asy?
-* Question 7.9::    Do you accept patches for Asymptote?
-
-
-
-File: asy-faq.info, Node: Question 7.1, Next: Question 7.2, Previous: Question 6.20, Up: Section 7
-
-Question 7.1.  Is Asymptote an interpreter or a compiler?
-
-Asymptote compiles Asymptote commands into its own virtual machine code.
-It  then runs this pseudocode on a virtual machine to produce PostScript
-code.
-
-
-File: asy-faq.info, Node: Question 7.2, Next: Question 7.3, Previous: Question 7.1, Up: Section 7
-
-Question 7.2.  What is the difference between a frame and a picture?
-
-Frames are canvases for drawing in PostScript coordinates. While working
-with frames directly is occasionally necessary for constructing deferred
-drawing routines, pictures are usually more convenient to work with.  See
-*Note Question 8.8:: `In MetaPost, it is possible to have a drawing remain
-the same size in different pictures by defining a unit u and explicitly
-multiply all the coordinates by u. Is there a better way to do this in
-Asymptote?'.
-
-
-File: asy-faq.info, Node: Question 7.3, Next: Question 7.4, Previous: Question 7.2, Up: Section 7
-
-Question 7.3.  What is the difference between a path and a guide?
-
-A path is a cubic spline with fixed endpoint conditions.
-
-A guide is an unresolved cubic spline (list of cubic-spline nodes and
-control points). A guide is like a path except that the computation of the
-cubic spline is deferred until drawing time (when it is resolved into a
-path); this allows two guides with free endpoint conditions to be joined
-together smoothly.
-
-
-File: asy-faq.info, Node: Question 7.4, Next: Question 7.5, Previous: Question 7.3, Up: Section 7
-
-Question 7.4.  What is a convenient way to declare and initialize an array of pictures?
-
-You could write yourself a routine such as:
-picture[] picture(int n) { 
-  picture[] pic;
-  for(int i=0; i < n; ++i) { 
-    pic[i]=new picture;
-    size(pic[i],19cm,0);
-  } 
-  return pic;
-} 
- 
-picture[] pic=picture(6);
-
-File: asy-faq.info, Node: Question 7.5, Next: Question 7.6, Previous: Question 7.4, Up: Section 7
-
-Question 7.5.  Is there a way to define functions that act on arrays in general (i.e. work for arrays of any type)?
-
-Generic types aren't yet implemented.
-
-But for now you can at least say
-typedef string T;
-include F;
- 
-typedef real T;
-include F;
-where F.asy contains some type-dependent code like
-T[] operator $(T A, T B) {return new T[] {A,B};}
-
-File: asy-faq.info, Node: Question 7.6, Next: Question 7.7, Previous: Question 7.5, Up: Section 7
-
-Question 7.6.  Is there any way to declare structures ahead of their definition, e.g. where struct A performs some operation on struct B, but B contains an A member?
-
-Asymptote does not support forward declaration of types. You can, however,
-nest structures, so that both types are visible for parts of the bodies of
-both structure definitions. For example:
-
-struct B { 
-  typedef void someroutine(B b);
- 
-  static struct A { 
-    someroutine routine;
-    void operator init(someroutine routine) { 
-      this.routine=routine;
-    } 
-  } 
- 
-  string test="Testing";
-} 
- 
-typedef B.A A;
- 
-A a=B.A(new void(B b){write(b.test);});
- 
-B b;
-a.routine(b);
-
-File: asy-faq.info, Node: Question 7.7, Next: Question 7.8, Previous: Question 7.6, Up: Section 7
-
-Question 7.7.  Where are static variables in for loops allocated?
-
-In the example
-
-void f() { 
-  for(int i=0; i < 3; ++i) { 
-    static int n;
-    ++n;
-    write(n);
-  }
-} 
-
-f(); // Writes 1, 2, 3
-the static qualifier means that n is allocated not just outside of the for
-loop, but also outside the function. This is clear if you call  f multiple
-times; there is still only one instance of n.
-
-The "level" of a variable (where it is allocated) has nothing to do with
-the "scope" of a variable (how long it can be referred to by name).  The
-curly braces enclosing a block affect only a variable's scope, not its
-level.
-
-Static modifiers are meaningless at the top level; they generate a warning
-and are simply ignored:
-
-for(int i=0; i < 3; ++i) { 
-  static int n;
-  ++n;
-  write(n);
-}
-// Writes warning about top-level static modifier and then 1, 1, 1
-Since version 1.22, non-static variables allocated in a loop body are
-allocated anew every iteration.  This is only noticable in obscure cases
-where a variable in a loop is accessed in the closure of a function
-defined in the loop:
-
-int f();
- 
-for(int i=0; i < 10; ++i) { 
-  int j=10*i;
-  if(i == 5)
-    f=new int() {return j;};
-} 
- 
-write(f()); // Writes 50
-Variables in the body of a loop last as long as that iteration of the
-loop, unless they are kept alive by a function closure as in the example
-above.  In a function body, variables will last at least as long as the
-function call, though because of closures and garbage collection, they may
-last longer than that.  If defined at the top level of a file or at the
-interactive prompt, they will last at least until the end of the file or
-prompt's run.
-
-
-File: asy-faq.info, Node: Question 7.8, Next: Question 7.9, Previous: Question 7.7, Up: Section 7
-
-Question 7.8.  Is there a debugger for asy?
-
-Yes, Asymptote includes a line-based debugger:
-
-http://asymptote.sourceforge.net/doc/Debugger.html
-
-
-File: asy-faq.info, Node: Question 7.9, Next: Question 8.1, Previous: Question 7.8, Up: Section 7
-
-Question 7.9.  Do you accept patches for Asymptote?
-
-Yes, in fact we would prefer that users submit patches for customized
-features (to http://sourceforge.net/tracker/?atid=685685&group_id=120000)
-instead of relying on us to do all of the coding. Development will proceed
-faster that way.
-
-
-File: asy-faq.info, Node: Section 8, Next: Section 9, Previous: Section 7, Up: Top
-
-Questions about differences between Asymptote and MetaPost
-
-* Menu:
-* Question 8.1::    What is the equivalent of the MetaPost c[a,b]
-                    interpolation operator?
-* Question 8.2::    How does picture scaling differ in Asymptote and
-                    MetaPost?
-* Question 8.3::    How can I avoid automatic scaling of a picture?
-* Question 8.4::    What is the equivalent of MetaPost ... command?
-* Question 8.5::    What is the equivalent of the MetaPost pickup command?
-* Question 8.6::    What is the equivalent of the MetaPost whatever
-                    command?
-* Question 8.7::    What is the equivalent for the MetaPost command for
-                    lray - horiz*v - verti*u = whatever*(LightSource - R),
-                    a system of three linear equations for three unknowns:
-                    horiz, verti, whatever?
-* Question 8.8::    In MetaPost, it is possible to have a drawing remain
-                    the same size in different pictures by defining a unit
-                    u and explicitly multiply all the coordinates by u. Is
-                    there a better way to do this in Asymptote?
-* Question 8.9::    In MetaPost, one could produce tiling pictures by
-                    generating a picture, and then clipping the picture to
-                    a rectangle of fixed dimensions around the center of
-                    the picture. How is that done in Asymptote?
-
-
-
-File: asy-faq.info, Node: Question 8.1, Next: Question 8.2, Previous: Question 7.9, Up: Section 8
-
-Question 8.1.  What is the equivalent of the MetaPost c[a,b] interpolation operator?
-
-interp(a,b,c);
-
-File: asy-faq.info, Node: Question 8.2, Next: Question 8.3, Previous: Question 8.1, Up: Section 8
-
-Question 8.2.  How does picture scaling differ in Asymptote and MetaPost?
-
-Asymptote includes an optional facility to do automatic scaling of
-pictures to achieve a given overall picture size, whereas Metapost only
-supports manual scaling. Asymptote defers drawing of objects drawn to
-pictures and distinguishes between true-size objects and objects that
-should scale with the picture size. The resulting linear programming
-problem is solved via the Simplex method.
-
-See the http://asymptote.sourceforge.net/gallery/dimension.asy example for
-an example of how deferred drawing is used to accomodate both user and
-true-size (PostScript) coordinates.
-
-
-File: asy-faq.info, Node: Question 8.3, Next: Question 8.4, Previous: Question 8.2, Up: Section 8
-
-Question 8.3.  How can I avoid automatic scaling of a picture?
-
-If you really like Metapost-style manual (hard-wired) scaling either:
-
-(i) use the default size(0,0) for the entire picture and do all of the
-scaling by hand, just like in MetaPost;
-
-(ii) draw to a separate picture pic and add(pic.fit());
-
-(iii) use frames.
-
-
-File: asy-faq.info, Node: Question 8.4, Next: Question 8.5, Previous: Question 8.3, Up: Section 8
-
-Question 8.4.  What is the equivalent of MetaPost ... command?
-
-The connector :: is a macro for tension atleast 1:
-
-size(100);
-pair z0=(0,0);
-pair z1=(1,0.25);
-pair z2=(2,0);
-draw(z0{up}::z1{right}::z2{down});
-
-File: asy-faq.info, Node: Question 8.5, Next: Question 8.6, Previous: Question 8.4, Up: Section 8
-
-Question 8.5.  What is the equivalent of the MetaPost pickup command?
-
-Just say, for example:
-
-currentpen=red;
-
-File: asy-faq.info, Node: Question 8.6, Next: Question 8.7, Previous: Question 8.5, Up: Section 8
-
-Question 8.6.  What is the equivalent of the MetaPost whatever command?
-
-Asymptote does not implicitly solve linear equations and therefore does
-not have the notion of a whatever unknown. Such a facility could certainly
-be added (perhaps using the notation ?= since = means assignment).
-However, the most common uses of whatever in MetaPost are covered by
-functions like extension in math.asy:
-pair extension(pair P, pair Q, pair p, pair q);
-this returns the intersection point of the extensions of the line segments
-PQ and pq. We find using routines like extension more explicit and less
-confusing to new users. But we could be persuaded to add something similar
-if someone can justify the need. In the meantime, one can always use the
-explicit built-in linear solver solve (see
-http://asymptote.sourceforge.net/doc/solve.html), which uses LU
-decomposition.
-
-
-File: asy-faq.info, Node: Question 8.7, Next: Question 8.8, Previous: Question 8.6, Up: Section 8
-
-Question 8.7.  What is the equivalent for the MetaPost command for lray - horiz*v - verti*u = whatever*(LightSource - R), a system of three linear equations for three unknowns: horiz, verti, whatever?
-
-Since horiz*v+verti*u spans a plane, you could use
-real intersect(vector P, vector Q, vector n, vector Z);
-to find the intersection time for the line  lray-whatever*(LightSource -
-R) and then extract the three desired values from there. (You'll still
-need to use the built-in explicit linear solver to solve a 2x2 system to
-get  horiz and verti.)
-
-
-File: asy-faq.info, Node: Question 8.8, Next: Question 8.9, Previous: Question 8.7, Up: Section 8
-
-Question 8.8.  In MetaPost, it is possible to have a drawing remain the same size in different pictures by defining a unit u and explicitly multiply all the coordinates by u. Is there a better way to do this in Asymptote?
-
-Yes, Asymptote has a better way: you definitely don't want to manually
-scale  all of your coordinates. To make the user coordinates represent
-multiples of exactly 1cm:
-
-unitsize(1cm);
-draw(unitsquare);
-One can also specify different x and y unit sizes:
-
-unitsize(x=1cm,y=2cm);
-draw(unitsquare);
-Another way is to draw your fixed size object to a frame and add it to
-currentpicture like this:
-
-path p=(0,0)--(1,0);
-frame object;
-draw(object,scale(100)*p);
- 
-add(object);
-add(object,(0,-10));
-To understand the difference between frames and pictures, try this:
-
-size(300,300);
- 
-path p=(0,0)--(1,0);
-picture object;
-draw(object,scale(100)*p);
- 
-add(object);
-add(object,(0,-10)); // Adds truesize object to currentpicture 
-
-File: asy-faq.info, Node: Question 8.9, Next: Question 9.1, Previous: Question 8.8, Up: Section 8
-
-Question 8.9.  In MetaPost, one could produce tiling pictures by generating a picture, and then clipping the picture to a rectangle of fixed dimensions around the center of the picture. How is that done in Asymptote?
-
-If you are using currentpicture the way one would in MetaPost (drawing in
-raw PostScript coordinates), you can simply do something like:
-
-fill((0,0)--(100,100)--(200,0)--cycle);
- 
-pair center(picture pic=currentpicture) {return 0.5*(pic.min()+pic.max());} 
- 
-real height=100;
-real width=100;
-pair delta=0.5(width,height);
-pair c=center();
-clip(box(c-delta,c+delta));
-However, drawing in PostScript coordinates is often inconvenient. Here's
-the  Asymptote way of doing the same thing, using deferred drawing:
-
-size(200,100);
-fill((0,0)--(1,1)--(2,0)--cycle);
- 
-void clip(picture pic=currentpicture, real width, real height) 
-{
-  pic.clip(new void (frame f, transform) { 
-    pair center=0.5(min(f)+max(f));
-    pair delta=0.5(width,height);
-    clip(f,box(center-delta,center+delta));
-  });
-} 
- 
-clip(100,100);
-See also the discussion of tilings in the documentation:
-http://asymptote.sourceforge.net/doc/Pens.html.
-
-
-File: asy-faq.info, Node: Section 9, Previous: Section 8, Up: Top
-
-Questions about output
-
-* Menu:
-* Question 9.1::    How can I disable automatic invocation of the PS
-                    viewer after an asy file is done processing?
-* Question 9.2::    How do I output jpeg images?
-* Question 9.3::    Can I embed bitmaps (photos) into my drawings and
-                    position and scale them?
-* Question 9.4::    Does Asymptote support direct PDF output?
-* Question 9.5::    How to I produce large pictures of high quality in
-                    raster format (e.g. png, giff etc).
-* Question 9.6::    Is it possible to produce multi-page documents with
-                    asymptote?
-
-
-
-File: asy-faq.info, Node: Question 9.1, Next: Question 9.2, Previous: Question 8.9, Up: Section 9
-
-Question 9.1.  How can I disable automatic invocation of the PS viewer after an asy file is done processing?
-
-It's actually not on by default, unless you happen to be using Microsoft
-Windows (because that is what most Microsoft Windows users expect).
-Microsoft Windows users can turn this feature off with the command-line
-option -noV or by putting
-
-import settings;
-interactiveView=false;
-batchView=false;
-in their config.asy file. See
-http://asymptote.sourceforge.net/doc/Options.html.
-
-
-File: asy-faq.info, Node: Question 9.2, Next: Question 9.3, Previous: Question 9.1, Up: Section 9
-
-Question 9.2.  How do I output jpeg images?
-
-If you have the ImageMagick convert program installed, simply type
-
-asy -f jpg test.asy 
-
-File: asy-faq.info, Node: Question 9.3, Next: Question 9.4, Previous: Question 9.2, Up: Section 9
-
-Question 9.3.  Can I embed bitmaps (photos) into my drawings and position and scale them?
-
-Convert them to eps format and use the graphic(string) function just like
-a Label:
-
-label(graphic("file"),(0,0));
-See the example http://asymptote.sourceforge.net/gallery/orthocenter.asy
-and http://asymptote.sourceforge.net/doc/label.html.
-
-
-File: asy-faq.info, Node: Question 9.4, Next: Question 9.5, Previous: Question 9.3, Up: Section 9
-
-Question 9.4.  Does Asymptote support direct PDF output?
-
-Yes, PDF output can be produced by the -f pdf option or -tex pdflatex
-option.  This supports transparency, annotations, embedded movies, and
-U3D/PRC content.
-
-
-File: asy-faq.info, Node: Question 9.5, Next: Question 9.6, Previous: Question 9.4, Up: Section 9
-
-Question 9.5.  How to I produce large pictures of high quality in raster format (e.g. png, giff etc).
-
-Try using some of the options to convert, mainly -geometry and -density.
-For example:
-convert -geometry 1000x3000 example.eps example.png 
-You can also change the default resolution of the image with:
-convert -geometry 1000x3000 -density 300 -units PixelsPerInch example.eps example.png 
-This does not change the number of pixels in the image, but just gives a
-hint  as to how large each pixel should be displayed.
-
-If you include the -density option without the -geometry option, convert
-will  keep the image size constant (so a 4cm x 3cm eps figure will
-generate a 4cm x 3cm png  image).
-
-
-File: asy-faq.info, Node: Question 9.6, Previous: Question 9.5, Up: Section 9
-
-Question 9.6.  Is it possible to produce multi-page documents with asymptote?
-
-Yes, simply call the newpage() function. This is used by the slide.asy
-package to produce high-quality slide presentations (easier to use than
-Prosper).
-
diff --git a/Build/source/utils/asymptote/doc/FAQ/install-sh b/Build/source/utils/asymptote/doc/FAQ/install-sh
index 04367377519..6781b987bdb 100755
--- a/Build/source/utils/asymptote/doc/FAQ/install-sh
+++ b/Build/source/utils/asymptote/doc/FAQ/install-sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile
 
-scriptversion=2013-10-30.23; # UTC
+scriptversion=2009-04-28.21; # UTC
 
 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@@ -35,21 +35,25 @@ scriptversion=2013-10-30.23; # UTC
 # FSF changes to this file are in the public domain.
 #
 # Calling this script install-sh is preferred over install.sh, to prevent
-# 'make' implicit rules from creating a file called install from it
+# `make' implicit rules from creating a file called install from it
 # when there is no Makefile.
 #
 # This script is compatible with the BSD install script, but was written
 # from scratch.
 
-tab='	'
 nl='
 '
-IFS=" $tab$nl"
+IFS=" ""	$nl"
 
-# Set DOITPROG to "echo" to test this script.
+# set DOITPROG to echo to test this script
 
+# Don't use :- since 4.3BSD and earlier shells don't like it.
 doit=${DOITPROG-}
-doit_exec=${doit:-exec}
+if test -z "$doit"; then
+  doit_exec=exec
+else
+  doit_exec=$doit
+fi
 
 # Put in absolute file names if you don't have them in your path;
 # or use environment vars.
@@ -64,6 +68,17 @@ mvprog=${MVPROG-mv}
 rmprog=${RMPROG-rm}
 stripprog=${STRIPPROG-strip}
 
+posix_glob='?'
+initialize_posix_glob='
+  test "$posix_glob" != "?" || {
+    if (set -f) 2>/dev/null; then
+      posix_glob=
+    else
+      posix_glob=:
+    fi
+  }
+'
+
 posix_mkdir=
 
 # Desired mode of installed file.
@@ -122,39 +137,36 @@ while test $# -ne 0; do
     -d) dir_arg=true;;
 
     -g) chgrpcmd="$chgrpprog $2"
-        shift;;
+	shift;;
 
     --help) echo "$usage"; exit $?;;
 
     -m) mode=$2
-        case $mode in
-          *' '* | *"$tab"* | *"$nl"* | *'*'* | *'?'* | *'['*)
-            echo "$0: invalid mode: $mode" >&2
-            exit 1;;
-        esac
-        shift;;
+	case $mode in
+	  *' '* | *'	'* | *'
+'*	  | *'*'* | *'?'* | *'['*)
+	    echo "$0: invalid mode: $mode" >&2
+	    exit 1;;
+	esac
+	shift;;
 
     -o) chowncmd="$chownprog $2"
-        shift;;
+	shift;;
 
     -s) stripcmd=$stripprog;;
 
     -t) dst_arg=$2
-        # Protect names problematic for 'test' and other utilities.
-        case $dst_arg in
-          -* | [=\(\)!]) dst_arg=./$dst_arg;;
-        esac
-        shift;;
+	shift;;
 
     -T) no_target_directory=true;;
 
     --version) echo "$0 $scriptversion"; exit $?;;
 
-    --) shift
-        break;;
+    --)	shift
+	break;;
 
-    -*) echo "$0: invalid option: $1" >&2
-        exit 1;;
+    -*)	echo "$0: invalid option: $1" >&2
+	exit 1;;
 
     *)  break;;
   esac
@@ -174,10 +186,6 @@ if test $# -ne 0 && test -z "$dir_arg$dst_arg"; then
     fi
     shift # arg
     dst_arg=$arg
-    # Protect names problematic for 'test' and other utilities.
-    case $dst_arg in
-      -* | [=\(\)!]) dst_arg=./$dst_arg;;
-    esac
   done
 fi
 
@@ -186,17 +194,13 @@ if test $# -eq 0; then
     echo "$0: no input file specified." >&2
     exit 1
   fi
-  # It's OK to call 'install-sh -d' without argument.
+  # It's OK to call `install-sh -d' without argument.
   # This can happen when creating conditional directories.
   exit 0
 fi
 
 if test -z "$dir_arg"; then
-  do_exit='(exit $ret); exit $ret'
-  trap "ret=129; $do_exit" 1
-  trap "ret=130; $do_exit" 2
-  trap "ret=141; $do_exit" 13
-  trap "ret=143; $do_exit" 15
+  trap '(exit $?); exit' 1 2 13 15
 
   # Set umask so as not to create temps with too-generous modes.
   # However, 'strip' requires both read and write access to temps.
@@ -207,16 +211,16 @@ if test -z "$dir_arg"; then
 
     *[0-7])
       if test -z "$stripcmd"; then
-        u_plus_rw=
+	u_plus_rw=
       else
-        u_plus_rw='% 200'
+	u_plus_rw='% 200'
       fi
       cp_umask=`expr '(' 777 - $mode % 1000 ')' $u_plus_rw`;;
     *)
       if test -z "$stripcmd"; then
-        u_plus_rw=
+	u_plus_rw=
       else
-        u_plus_rw=,u+rw
+	u_plus_rw=,u+rw
       fi
       cp_umask=$mode$u_plus_rw;;
   esac
@@ -224,9 +228,9 @@ fi
 
 for src
 do
-  # Protect names problematic for 'test' and other utilities.
+  # Protect names starting with `-'.
   case $src in
-    -* | [=\(\)!]) src=./$src;;
+    -*) src=./$src;;
   esac
 
   if test -n "$dir_arg"; then
@@ -248,20 +252,51 @@ do
       echo "$0: no destination specified." >&2
       exit 1
     fi
+
     dst=$dst_arg
+    # Protect names starting with `-'.
+    case $dst in
+      -*) dst=./$dst;;
+    esac
 
     # If destination is a directory, append the input filename; won't work
     # if double slashes aren't ignored.
     if test -d "$dst"; then
       if test -n "$no_target_directory"; then
-        echo "$0: $dst_arg: Is a directory" >&2
-        exit 1
+	echo "$0: $dst_arg: Is a directory" >&2
+	exit 1
       fi
       dstdir=$dst
       dst=$dstdir/`basename "$src"`
       dstdir_status=0
     else
-      dstdir=`dirname "$dst"`
+      # Prefer dirname, but fall back on a substitute if dirname fails.
+      dstdir=`
+	(dirname "$dst") 2>/dev/null ||
+	expr X"$dst" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
+	     X"$dst" : 'X\(//\)[^/]' \| \
+	     X"$dst" : 'X\(//\)$' \| \
+	     X"$dst" : 'X\(/\)' \| . 2>/dev/null ||
+	echo X"$dst" |
+	    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\/\)[^/].*/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\/\)$/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\).*/{
+		   s//\1/
+		   q
+		 }
+		 s/.*/./; q'
+      `
+
       test -d "$dstdir"
       dstdir_status=$?
     fi
@@ -272,74 +307,74 @@ do
   if test $dstdir_status != 0; then
     case $posix_mkdir in
       '')
-        # Create intermediate dirs using mode 755 as modified by the umask.
-        # This is like FreeBSD 'install' as of 1997-10-28.
-        umask=`umask`
-        case $stripcmd.$umask in
-          # Optimize common cases.
-          *[2367][2367]) mkdir_umask=$umask;;
-          .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
-
-          *[0-7])
-            mkdir_umask=`expr $umask + 22 \
-              - $umask % 100 % 40 + $umask % 20 \
-              - $umask % 10 % 4 + $umask % 2
-            `;;
-          *) mkdir_umask=$umask,go-w;;
-        esac
-
-        # With -d, create the new directory with the user-specified mode.
-        # Otherwise, rely on $mkdir_umask.
-        if test -n "$dir_arg"; then
-          mkdir_mode=-m$mode
-        else
-          mkdir_mode=
-        fi
-
-        posix_mkdir=false
-        case $umask in
-          *[123567][0-7][0-7])
-            # POSIX mkdir -p sets u+wx bits regardless of umask, which
-            # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
-            ;;
-          *)
-            tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
-            trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
-
-            if (umask $mkdir_umask &&
-                exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
-            then
-              if test -z "$dir_arg" || {
-                   # Check for POSIX incompatibilities with -m.
-                   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
-                   # other-writable bit of parent directory when it shouldn't.
-                   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
-                   ls_ld_tmpdir=`ls -ld "$tmpdir"`
-                   case $ls_ld_tmpdir in
-                     d????-?r-*) different_mode=700;;
-                     d????-?--*) different_mode=755;;
-                     *) false;;
-                   esac &&
-                   $mkdirprog -m$different_mode -p -- "$tmpdir" && {
-                     ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
-                     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
-                   }
-                 }
-              then posix_mkdir=:
-              fi
-              rmdir "$tmpdir/d" "$tmpdir"
-            else
-              # Remove any dirs left behind by ancient mkdir implementations.
-              rmdir ./$mkdir_mode ./-p ./-- 2>/dev/null
-            fi
-            trap '' 0;;
-        esac;;
+	# Create intermediate dirs using mode 755 as modified by the umask.
+	# This is like FreeBSD 'install' as of 1997-10-28.
+	umask=`umask`
+	case $stripcmd.$umask in
+	  # Optimize common cases.
+	  *[2367][2367]) mkdir_umask=$umask;;
+	  .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
+
+	  *[0-7])
+	    mkdir_umask=`expr $umask + 22 \
+	      - $umask % 100 % 40 + $umask % 20 \
+	      - $umask % 10 % 4 + $umask % 2
+	    `;;
+	  *) mkdir_umask=$umask,go-w;;
+	esac
+
+	# With -d, create the new directory with the user-specified mode.
+	# Otherwise, rely on $mkdir_umask.
+	if test -n "$dir_arg"; then
+	  mkdir_mode=-m$mode
+	else
+	  mkdir_mode=
+	fi
+
+	posix_mkdir=false
+	case $umask in
+	  *[123567][0-7][0-7])
+	    # POSIX mkdir -p sets u+wx bits regardless of umask, which
+	    # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
+	    ;;
+	  *)
+	    tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
+	    trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
+
+	    if (umask $mkdir_umask &&
+		exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
+	    then
+	      if test -z "$dir_arg" || {
+		   # Check for POSIX incompatibilities with -m.
+		   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
+		   # other-writeable bit of parent directory when it shouldn't.
+		   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
+		   ls_ld_tmpdir=`ls -ld "$tmpdir"`
+		   case $ls_ld_tmpdir in
+		     d????-?r-*) different_mode=700;;
+		     d????-?--*) different_mode=755;;
+		     *) false;;
+		   esac &&
+		   $mkdirprog -m$different_mode -p -- "$tmpdir" && {
+		     ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
+		     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
+		   }
+		 }
+	      then posix_mkdir=:
+	      fi
+	      rmdir "$tmpdir/d" "$tmpdir"
+	    else
+	      # Remove any dirs left behind by ancient mkdir implementations.
+	      rmdir ./$mkdir_mode ./-p ./-- 2>/dev/null
+	    fi
+	    trap '' 0;;
+	esac;;
     esac
 
     if
       $posix_mkdir && (
-        umask $mkdir_umask &&
-        $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir"
+	umask $mkdir_umask &&
+	$doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir"
       )
     then :
     else
@@ -349,51 +384,53 @@ do
       # directory the slow way, step by step, checking for races as we go.
 
       case $dstdir in
-        /*) prefix='/';;
-        [-=\(\)!]*) prefix='./';;
-        *)  prefix='';;
+	/*) prefix='/';;
+	-*) prefix='./';;
+	*)  prefix='';;
       esac
 
+      eval "$initialize_posix_glob"
+
       oIFS=$IFS
       IFS=/
-      set -f
+      $posix_glob set -f
       set fnord $dstdir
       shift
-      set +f
+      $posix_glob set +f
       IFS=$oIFS
 
       prefixes=
 
       for d
       do
-        test X"$d" = X && continue
-
-        prefix=$prefix$d
-        if test -d "$prefix"; then
-          prefixes=
-        else
-          if $posix_mkdir; then
-            (umask=$mkdir_umask &&
-             $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
-            # Don't fail if two instances are running concurrently.
-            test -d "$prefix" || exit 1
-          else
-            case $prefix in
-              *\'*) qprefix=`echo "$prefix" | sed "s/'/'\\\\\\\\''/g"`;;
-              *) qprefix=$prefix;;
-            esac
-            prefixes="$prefixes '$qprefix'"
-          fi
-        fi
-        prefix=$prefix/
+	test -z "$d" && continue
+
+	prefix=$prefix$d
+	if test -d "$prefix"; then
+	  prefixes=
+	else
+	  if $posix_mkdir; then
+	    (umask=$mkdir_umask &&
+	     $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
+	    # Don't fail if two instances are running concurrently.
+	    test -d "$prefix" || exit 1
+	  else
+	    case $prefix in
+	      *\'*) qprefix=`echo "$prefix" | sed "s/'/'\\\\\\\\''/g"`;;
+	      *) qprefix=$prefix;;
+	    esac
+	    prefixes="$prefixes '$qprefix'"
+	  fi
+	fi
+	prefix=$prefix/
       done
 
       if test -n "$prefixes"; then
-        # Don't fail if two instances are running concurrently.
-        (umask $mkdir_umask &&
-         eval "\$doit_exec \$mkdirprog $prefixes") ||
-          test -d "$dstdir" || exit 1
-        obsolete_mkdir_used=true
+	# Don't fail if two instances are running concurrently.
+	(umask $mkdir_umask &&
+	 eval "\$doit_exec \$mkdirprog $prefixes") ||
+	  test -d "$dstdir" || exit 1
+	obsolete_mkdir_used=true
       fi
     fi
   fi
@@ -428,12 +465,15 @@ do
 
     # If -C, don't bother to copy if it wouldn't change the file.
     if $copy_on_change &&
-       old=`LC_ALL=C ls -dlL "$dst"     2>/dev/null` &&
-       new=`LC_ALL=C ls -dlL "$dsttmp"  2>/dev/null` &&
-       set -f &&
+       old=`LC_ALL=C ls -dlL "$dst"	2>/dev/null` &&
+       new=`LC_ALL=C ls -dlL "$dsttmp"	2>/dev/null` &&
+
+       eval "$initialize_posix_glob" &&
+       $posix_glob set -f &&
        set X $old && old=:$2:$4:$5:$6 &&
        set X $new && new=:$2:$4:$5:$6 &&
-       set +f &&
+       $posix_glob set +f &&
+
        test "$old" = "$new" &&
        $cmpprog "$dst" "$dsttmp" >/dev/null 2>&1
     then
@@ -446,24 +486,24 @@ do
       # to itself, or perhaps because mv is so ancient that it does not
       # support -f.
       {
-        # Now remove or move aside any old file at destination location.
-        # We try this two ways since rm can't unlink itself on some
-        # systems and the destination file might be busy for other
-        # reasons.  In this case, the final cleanup might fail but the new
-        # file should still install successfully.
-        {
-          test ! -f "$dst" ||
-          $doit $rmcmd -f "$dst" 2>/dev/null ||
-          { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
-            { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
-          } ||
-          { echo "$0: cannot unlink or rename $dst" >&2
-            (exit 1); exit 1
-          }
-        } &&
-
-        # Now rename the file to the real destination.
-        $doit $mvcmd "$dsttmp" "$dst"
+	# Now remove or move aside any old file at destination location.
+	# We try this two ways since rm can't unlink itself on some
+	# systems and the destination file might be busy for other
+	# reasons.  In this case, the final cleanup might fail but the new
+	# file should still install successfully.
+	{
+	  test ! -f "$dst" ||
+	  $doit $rmcmd -f "$dst" 2>/dev/null ||
+	  { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
+	    { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
+	  } ||
+	  { echo "$0: cannot unlink or rename $dst" >&2
+	    (exit 1); exit 1
+	  }
+	} &&
+
+	# Now rename the file to the real destination.
+	$doit $mvcmd "$dsttmp" "$dst"
       }
     fi || exit 1
 
diff --git a/Build/source/utils/asymptote/doc/TeXShopAndAsymptote.pdf b/Build/source/utils/asymptote/doc/TeXShopAndAsymptote.pdf
deleted file mode 100755
index 9abdc656892..00000000000
--- a/Build/source/utils/asymptote/doc/TeXShopAndAsymptote.pdf
+++ /dev/null
diff --git a/Build/source/utils/asymptote/doc/asy-latex.pdf b/Build/source/utils/asymptote/doc/asy-latex.pdf
deleted file mode 100755
index a91f302ce02..00000000000
--- a/Build/source/utils/asymptote/doc/asy-latex.pdf
+++ /dev/null
diff --git a/Build/source/utils/asymptote/doc/asy.1 b/Build/source/utils/asymptote/doc/asy.1
deleted file mode 100755
index 979fd50ee38..00000000000
--- a/Build/source/utils/asymptote/doc/asy.1
+++ /dev/null
@@ -1,297 +0,0 @@
-.\"                                      Hey, EMACS: -*- nroff -*-
-.TH ASY 1 "1 Dec 2004"
-.SH NAME
-asy \- Asymptote: a script-based vector graphics language
-.SH SYNOPSIS
-.B asy
-.RI [ options ]
-.RI [ file \ ...]
-.SH DESCRIPTION
-\fBAsymptote\fP is a powerful descriptive vector graphics language for
-technical drawings, inspired by MetaPost but with an improved C++-like syntax.
-Asymptote provides for figures the same high-quality level of typesetting that
-LaTeX does for scientific text.
-.SH OPTIONS
-If no arguments are given, Asymptote runs in interactive mode.
-.PP
-If "\-" is given as the file argument, Asymptote reads from standard input.
-.PP
-A summary of options is included below. The effect of most options
-can be negated by prepending 
-.B no
-to the option name. 
-Default values for most options may also be entered in the 
-file 
-.B .asy/config.asy
-in the user's home directory using the long form:
-.PP
-     import settings;
-     batchView=true;
-.PP
-For a complete
-description, see the Info files.
-.TP
-.B \-V,\-View             
-View output; command-line only.
-.TP
-.B \-a,\-align C|B|T|Z    
-Center, Bottom, Top, or Zero page alignment [C].
-.TP
-.B \-antialias n         
-Antialiasing width for rasterized output [2].
-.TP
-.B \-arcballradius pixels
-Arcball radius [750].
-.TP
-.B \-auto3D              
-Automatically activate 3D scene [true].
-.TP
-.B \-autobillboard       
-3D labels always face viewer by default [true].
-.TP
-.B \-autoimport string   
-Module to automatically import.
-.TP
-.B \-autoplain           
-Enable automatic importing of plain [true].
-.TP
-.B \-autoplay            
-Autoplay 3D animations [false].
-.TP
-.B \-autorotate          
-Enable automatic PDF page rotation [false].
-.TP
-.B \-axes3               
-Show 3D axes in PDF output [true].
-.TP
-.B \-batchMask           
-Mask fpu exceptions in batch mode [false].
-.TP
-.B \-batchView           
-View output in batch mode [false].
-.TP
-.B \-bw                  
-Convert all colors to black and white [false].
-.TP
-.B \-cd directory        
-Set current directory; command-line only.
-.TP
-.B \-cmyk                
-Convert rgb colors to cmyk [false].
-.TP
-.B \-c,\-command string   
-Command to autoexecute.
-.TP
-.B \-compact             
-Conserve memory at the expense of speed [false].
-.TP
-.B \-d,\-debug            
-Enable debugging messages [false].
-.TP
-.B \-divisor n           
-Garbage collect using purge(divisor=n) [2].
-.TP
-.B \-doubleclick ms      
-Emulated double-click timeout [200].
-.TP
-.B \-embed               
-Embed rendered preview image [true].
-.TP
-.B \-exitonEOF           
-Exit interactive mode on EOF [true].
-.TP
-.B \-fitscreen           
-Fit rendered image to screen [true].
-.TP
-.B \-framedelay ms       
-Additional frame delay [0].
-.TP
-.B \-framerate frames/s  
-Animation speed [30].
-.TP
-.B \-globalwrite         
-Allow write to other directory [false].
-.TP
-.B \-gray                
-Convert all colors to grayscale [false].
-.TP
-.B \-h,\-help             
-Show summary of options; command-line only.
-.TP
-.B \-historylines n      
-Retain n lines of history [1000].
-.TP
-.B \-iconify             
-Iconify rendering window [false].
-.TP
-.B \-inlineimage         
-Generate inline embedded image [false].
-.TP
-.B \-inlinetex           
-Generate inline TeX code [false].
-.TP
-.B \-interactiveMask     
-Mask fpu exceptions in interactive mode [true].
-.TP
-.B \-interactiveView     
-View output in interactive mode [true].
-.TP
-.B \-interactiveWrite    
-Write expressions entered at the prompt to stdout [true].
-.TP
-.B \-k,\-keep             
-Keep intermediate files [false].
-.TP
-.B \-keepaux             
-Keep intermediate LaTeX .aux files [false].
-.TP
-.B \-level n             
-Postscript level [3].
-.TP
-.B \-l,\-listvariables    
-List available global functions and variables [false].
-.TP
-.B \-localhistory        
-Use a local interactive history file [false].
-.TP
-.B \-loop                
-Loop 3D animations [false].
-.TP
-.B \-m,\-mask             
-Mask fpu exceptions; command-line only.
-.TP
-.B \-maxtile pair        
-Maximum rendering tile size [(1024,768)].
-.TP
-.B \-maxviewport pair    
-Maximum viewport size [(2048,2048)].
-.TP
-.B \-multiline           
-Input code over multiple lines at the prompt [false].
-.TP
-.B \-multipleView        
-View output from multiple batch-mode files [false].
-.TP
-.B \-multisample n       
-Multisampling width for screen images [4].
-.TP
-.B \-offscreen           
-Use offscreen rendering [false].
-.TP
-.B \-O,\-offset pair      
-PostScript offset [(0,0)].
-.TP
-.B \-f,\-outformat format 
-Convert each output file to specified format.
-.TP
-.B \-o,\-outname name     
-Alternative output directory/filename.
-.TP
-.B \-p,\-parseonly        
-Parse file [false].
-.TP
-.B \-pdfreload           
-Automatically reload document in pdfviewer [false].
-.TP
-.B \-pdfreloaddelay usec 
-Delay before attempting initial pdf reload [750000].
-.TP
-.B \-position pair       
-Initial 3D rendering screen position [(0,0)].
-.TP
-.B \-prc                 
-Embed 3D PRC graphics in PDF output [true].
-.TP
-.B \-prompt string       
-Prompt [> ].
-.TP
-.B \-prompt2 string      
-Continuation prompt for multiline input  [..].
-.TP
-.B \-q,\-quiet            
-Suppress welcome message [false].
-.TP
-.B \-render n            
-Render 3D graphics using n pixels per bp (-1=auto) [-1].
-.TP
-.B \-resizestep step     
-Resize step [1.2].
-.TP
-.B \-reverse             
-reverse 3D animations [false].
-.TP
-.B \-rgb                 
-Convert cmyk colors to rgb [false].
-.TP
-.B \-safe                
-Disable system call [true].
-.TP
-.B \-scroll n            
-Scroll standard output n lines at a time [0].
-.TP
-.B \-spinstep deg/s      
-Spin speed [60].
-.TP
-.B \-svgemulation        
-Emulate unimplemented SVG shading [false].
-.TP
-.B \-tabcompletion       
-Interactive prompt auto-completion [true].
-.TP
-.B \-tex engine          
-latex|pdflatex|xelatex|tex|pdftex|context|none [latex].
-.TP
-.B \-thick               
-Render thick 3D lines [true].
-.TP
-.B \-thin                
-Render thin 3D lines [true].
-.TP
-.B \-threads             
-Use POSIX threads for 3D rendering [true].
-.TP
-.B \-toolbar             
-Show 3D toolbar in PDF output [true].
-.TP
-.B \-s,\-translate        
-Show translated virtual machine code [false].
-.TP
-.B \-twice               
-Run LaTeX twice (to resolve references) [false].
-.TP
-.B \-twosided            
-Use two-sided 3D lighting model for rendering [true].
-.TP
-.B \-u,\-user string      
-General purpose user string.
-.TP
-.B \-v,\-verbose          
-Increase verbosity level (can specify multiple times) [0].
-.TP
-.B \-version             
-Show version; command-line only.
-.TP
-.B \-wait                
-Wait for child processes to finish before exiting [false].
-.TP
-.B \-warn string         
-Enable warning; command-line only.
-.TP
-.B \-where               
-Show where listed variables are declared [false].
-.TP
-.B \-zoomfactor factor   
-Zoom step factor [1.05].
-.TP
-.B \-zoomstep step       
-Mouse motion zoom step [0.1].
-
-.SH SEE ALSO
-Asymptote is documented fully in the asymptote Info page.
-The manual can also be accessed in interactive mode with the "help" command.
-
-.SH AUTHOR
-Asymptote was written by Andy Hammerlindl, John Bowman, and Tom Prince.
-.PP
-This manual page was written by Hubert Chan for the Debian project (but may
-be used by others).
diff --git a/Build/source/utils/asymptote/doc/asyRefCard.pdf b/Build/source/utils/asymptote/doc/asyRefCard.pdf
deleted file mode 100644
index 549deab1579..00000000000
--- a/Build/source/utils/asymptote/doc/asyRefCard.pdf
+++ /dev/null
diff --git a/Build/source/utils/asymptote/doc/asymptote.pdf b/Build/source/utils/asymptote/doc/asymptote.pdf
deleted file mode 100644
index fc83a4c44a6..00000000000
--- a/Build/source/utils/asymptote/doc/asymptote.pdf
+++ /dev/null
diff --git a/Build/source/utils/asymptote/doc/asymptote.texi b/Build/source/utils/asymptote/doc/asymptote.texi
index ff038453b10..9fabe5d813d 100644
--- a/Build/source/utils/asymptote/doc/asymptote.texi
+++ b/Build/source/utils/asymptote/doc/asymptote.texi
@@ -9,7 +9,7 @@ This file documents @code{Asymptote}, version @value{VERSION}.
 
 @url{http://asymptote.sourceforge.net}
      
-Copyright @copyright{} 2004-13 Andy Hammerlindl, John Bowman, and Tom Prince.
+Copyright @copyright{} 2004-14 Andy Hammerlindl, John Bowman, and Tom Prince.
      
 @quotation
 Permission is granted to copy, distribute and/or modify this document
@@ -89,7 +89,7 @@ Drawing commands
 Programming
 
 * Data types::                  void, bool, int, real, pair, triple, string
-* Paths and guides::
+* Paths and guides::            Bezier curves
 * Pens::                        Colors, line types, line widths, font sizes
 * Transforms::                  Affine transforms
 * Frames and pictures::         Canvases for immediate and deferred drawing
@@ -289,7 +289,7 @@ We recommend subscribing to new release announcements at
 @noindent
 Users may also wish to monitor the @code{Asymptote} forum:
 @quotation
-@url{http://sourceforge.net/projects/asymptote/forums/forum/409349}
+@url{http://sourceforge.net/p/asymptote/discussion/409349}
 @end quotation
 @noindent
 
@@ -491,6 +491,7 @@ configuration variables @code{paperwidth} and @code{paperheight}.
 @cindex @code{texcommand}
 @cindex @code{dvips}
 @cindex @code{dvisvgm}
+@cindex @code{libgs}
 @cindex @code{convert}
 @cindex @code{display}
 @cindex @code{animate}
@@ -501,6 +502,7 @@ texpath
 texcommand
 dvips
 dvisvgm
+libgs
 convert
 display
 animate
@@ -584,7 +586,8 @@ cd asymptote-x.xx
 @end verbatim
 By default the system version of the Boehm garbage collector will be
 used; if it is old we recommend first putting
-@url{http://www.hpl.hp.com/personal/Hans_Boehm/gc/gc_source/gc-7.2d.tar.gz}
+@url{http://hboehm.info/gc/gc_source/gc-7.4.0.tar.gz}
+@url{http://hboehm.info/gc/gc_source/libatomic_ops-7.4.0.tar.gz}
 in the @code{Asymptote} source directory.
 
 On @code{UNIX} platforms (other than @code{MacOS X}), we recommend
@@ -739,7 +742,7 @@ can be enabled by running @code{asy-kate.sh} in the
 The following commands are needed to install the latest development version of
 @code{Asymptote} using @code{Subversion}:
 @verbatim
-svn co http://asymptote.svn.sourceforge.net/svnroot/asymptote/trunk/asymptote
+svn co http://svn.code.sf.net/p/asymptote/code/trunk/asymptote 
 cd asymptote
 ./autogen.sh
 ./configure
@@ -974,10 +977,11 @@ external links posted at @url{http://asymptote.sourceforge.net}) for
 further examples, including two-dimensional and interactive
 three-dimensional scientific graphs. Additional examples have been
 posted by Philippe Ivaldi at @url{http://www.piprime.fr/asymptote}.
-A user-written @code{Asymptote} tutorial is available at
-@verbatim
-http://www.artofproblemsolving.com/Wiki/index.php/Asymptote:_Basics
-@end verbatim
+Excellent user-written @code{Asymptote} tutorials are also available:
+
+@url{http://www.artofproblemsolving.com/Wiki/index.php/Asymptote:_Basics}
+
+@url{http://math.uchicago.edu/~cstaats/Charles_Staats_III/Notes_and_papers_files/asymptote_tutorial.pdf}
 
 @node Drawing commands
 @chapter Drawing commands
@@ -1329,7 +1333,7 @@ using the vertex colors specified in the @math{n \times 4} pen array
 @code{p} and internal control points in the @math{n \times 4}
 array @code{z}, is implemented with
 @verbatim
-void tensorshade(picture pic=currentpicture, path g, bool stroke=false,
+void tensorshade(picture pic=currentpicture, path[] g, bool stroke=false,
                  pen fillrule=currentpen, pen[][] p, path[] b=g,
                  pair[][] z=new pair[][]);
 @end verbatim
@@ -1737,7 +1741,7 @@ In addition, it supports many features beyond the ones found in those languages.
 
 @menu
 * Data types::                  void, bool, int, real, pair, triple, string
-* Paths and guides::
+* Paths and guides::            Bezier curves
 * Pens::                        Colors, line types, line widths, font sizes
 * Transforms::                  Affine transforms
 * Frames and pictures::         Canvases for immediate and deferred drawing
@@ -2283,6 +2287,12 @@ path ellipse(pair c, real a, real b)
 }
 @end verbatim
 
+A brace can be constructed between pairs @code{a} and @code{b} with
+@cindex @code{brace}
+@verbatim
+path brace(pair a, pair b, real amplitude=bracedefaultratio*length(b-a));
+@end verbatim
+
 This example illustrates the use of all five guide connectors discussed
 in @ref{Tutorial} and @ref{Bezier curves}:
 @verbatiminclude join.asy
@@ -2565,6 +2575,16 @@ otherwise.
 returns an arbitrary point strictly inside a cyclic path @code{p}
 according to the fill rule @code{fillrule} (@pxref{fillrule}).
 
+@cindex @code{side}
+@item real side(pair a, pair b, pair c);
+determines the side of @code{a--b} that c lies on (negative=left,
+zero=on @code{a--b}, positive=right).
+
+@cindex @code{incircle}
+@item real incircle(pair a, pair b, pair c, pair d);
+determines the side of the counterclockwise circle through @code{a,b,c} that
+@code{d} lies on (negative=inside, 0=on circle, positive=right). 
+
 @cindex @code{strokepath}
 @item path[] strokepath(path g, pen p=currentpen);
 returns the path array that @code{PostScript} would fill in drawing path
@@ -4023,7 +4043,7 @@ struct T {
   int x;
 }
 
-T foo=new T;
+T foo;
 T bar=foo;
 bar.x=5;
 @end verbatim
@@ -4044,7 +4064,7 @@ struct T {
   ++Tcount;
 }
 
-T foo=new T;
+T foo;
 @end verbatim
 
 Here, the expression @code{new T} will produce a new instance of the class, but
@@ -4111,7 +4131,7 @@ struct Person {
   string lastname;
 }
 
-Person joe=new Person;
+Person joe;
 joe.firstname="Joe";
 joe.lastname="Jones";
 @end verbatim
@@ -4128,7 +4148,7 @@ struct Person {
   string lastname;
 
   static Person Person(string firstname, string lastname) {
-    Person p=new Person;
+    Person p;
     p.firstname=firstname;
     p.lastname=lastname;
     return p;
@@ -4164,7 +4184,7 @@ structure is called @code{Foo}):
 
 @example
 static Foo Foo(@var{args}) @{
-  Foo instance=new Foo;
+  Foo instance;
   instance.operator init(@var{args});
   return instance;
 @}
@@ -5441,7 +5461,7 @@ The virtual members @code{dimension}, @code{line}, @code{csv},
 @code{word}, and @code{read} of a file are useful for reading arrays.
 @cindex @code{line}
 For example, if line mode is set with @code{file line(bool b=true)}, then
-reading will stop once the end of the line is reached instead
+reading will stop once the end of the line is reached instead:
 @verbatim
 file fin=input("test.txt");
 real[] A=fin.line();
@@ -6468,7 +6488,6 @@ This module provides an interface to the @code{LaTeX} package
 @end quotation
 @noindent
 for embedding movies, sounds, and 3D objects into a @acronym{PDF} document.
-Version 0.13 (2012/09/12) of @code{media9} or later is required.
 
 @cindex @code{external}
 A more portable method for embedding movie files, which should work on any
@@ -7861,7 +7880,7 @@ In addition to the default @code{settings.prc=true}, this requires
 @code{settings.outformat="pdf"}, which can be specified by the command
 line option @code{-f pdf}, put in the @code{Asymptote} configuration
 file (@pxref{configuration file}), or specified in the script before
-@code{three.asy} (or @code{graph3.asy}) is imported. 
+@code{three.asy} (or @code{graph3.asy}) is imported.
 The @code{media9} LaTeX package is also required (@pxref{embed}).
 The example @code{pdb.asy} illustrates 
 how one can generate a list of predefined views (see @code{100d.views}).
@@ -7872,6 +7891,8 @@ file @code{externalprc.tex} illustrates how the resulting @acronym{PRC} and
 rendered image files can be extracted and processed in a separate
 @code{LaTeX} file. However, see @ref{LaTeX usage} for an easier way
 to embed three-dimensional @code{Asymptote} pictures within @code{LaTeX}.
+For specialized applications where only the raw @acronym{PRC} file is
+required, specify @code{settings.outformat="prc"}.
 The open-source @acronym{PRC} specification is available from
 @url{http://livedocs.adobe.com/acrobat_sdk/9/Acrobat9_HTMLHelp/API_References/PRCReference/PRC_Format_Specification/}.
 
@@ -8288,7 +8309,7 @@ real[][] intersections(path3 p, surface s, real fuzz=-1);
 @end verbatim
 @noindent
 returns the intersection times of a path @code{p} with a surface
-@code{s} as a sorted array of real arrays of length 2, and
+@code{s} as a sorted array of real arrays of length 3, and
 @cindex @code{intersectionpoints}
 @verbatim
 triple[] intersectionpoints(path3 p, surface s, real fuzz=-1);
@@ -9008,13 +9029,13 @@ variables may also be changed at runtime.
 @cindex @code{gsOptions}
 @cindex @code{psviewerOptions}
 @cindex @code{pdfviewerOptions}
+@cindex @code{pdfreloadOptions}
 @cindex @code{glOptions}
+@cindex @code{dvisvgmOptions}
 The advanced configuration variables @code{dvipsOptions},
 @code{hyperrefOptions}, @code{convertOptions}, @code{gsOptions},
-@code{psviewerOptions}, @code{pdfviewerOptions}, and @code{glOptions}
-allow specialized options to be passed as a string to the respective
-applications or libraries. The default value of @code{hyperrefOptions}
-is @code{setpagesize=false,unicode,pdfborder=0 0 0}.
+@code{psviewerOptions}, @code{pdfviewerOptions}, @code{pdfreloadOptions},
+@code{glOptions}, and @code{dvisvgmOptions} allow specialized options to be passed as a string to the respective applications or libraries. The default value of @code{hyperrefOptions} is @code{setpagesize=false,unicode,pdfborder=0 0 0}.
 
 If you insert
 @verbatim
@@ -9039,16 +9060,17 @@ at the beginning of the configuration file, it can contain arbitrary
 @cindex @code{context}
 @cindex @code{EPS}
 @cindex @code{PDF}
-@cindex @code{SVG}
 @anchor{convert}
 The default output format is @acronym{EPS} for the (default)
 @code{latex} and @code{tex} tex engine and @acronym{PDF} for the
 @code{pdflatex}, @code{xelatex}, and @code{context} tex engines.
 Alternative output formats may be produced using the @code{-f} option 
-(or @code{outformat} setting). To produce @acronym{SVG} output,
-first install @code{dvisvgm} (version 0.8.7 or later) from
-@url{http://dvisvgm.sourceforge.net/down.html} and be sure to use the
-@code{latex} or @code{tex} tex engine.
+(or @code{outformat} setting). 
+
+@cindex @code{SVG}
+@cindex @code{dvisvgm}
+@cindex @code{libgs}
+To produce @acronym{SVG} output, you will need @code{dvisvgm} (version 0.8.7 or later) from @url{http://dvisvgm.sourceforge.net} and must use the @code{latex} or @code{tex} tex engine. You might need to adjust the configuration variable @code{libgs} to point to the location of your ghostscript library @code{libgs.so} (or to an empty string, depending on how @code{dvisvgm} was configured).
 
 @code{Asymptote} can also produce any output format supported
 by the @code{ImageMagick} @code{convert} program (version 6.3.5 or
@@ -9358,7 +9380,7 @@ Questions on installing and using @code{Asymptote} that are not
 addressed in the @acronym{FAQ} should be sent to the
 @code{Asymptote} forum: 
 @quotation
-@url{http://sourceforge.net/projects/asymptote/forums/forum/409349}
+@url{http://sourceforge.net/p/asymptote/discussion/409349}
 @end quotation
 @noindent
 Including an example that illustrates what you are trying to do will help
@@ -9700,16 +9722,20 @@ Mark Henning, Steve Melenchuk, Martin Wiebusch, and Stefan Knorr.
 @c  LocalWords:  lineargraph0 scalings log2 log2graph 5cm BWRainbow2
 @c  LocalWords:  guide3 path3 unitcircle3 2E 2n noV 100d PostScript3D
 @c  LocalWords:  size3 fit3 theta1 phi1 theta2 phi2 v1 v2 unitsquare3
-@c  LocalWords:  t1 t2 5z 5y transform3 identity4 xscale3 yscale3
-@c  LocalWords:  zscale3 scale3 join3 BeginBar3 EndBar3 Bar3 Bars3
+@c  LocalWords:  t1 t2 5z 5y transform3 identity4 xscale3 yscale3 0pt
+@c  LocalWords:  zscale3 scale3 join3 BeginBar3 EndBar3 Bar3 Bars3 's
 @c  LocalWords:  BeginArrow3 MidArrow3 EndArrow3 Arrow3 Arrows3 axes3
-@c  LocalWords:  BeginArcArrow3 MidArcArrow3 EndArcArrow3 ArcArrow3
+@c  LocalWords:  BeginArcArrow3 MidArcArrow3 EndArcArrow3 ArcArrow3 '
 @c  LocalWords:  ArcArrows3 DefaultHead3 HookHead3 TeXHead3 HookHead2
 @c  LocalWords:  DefaultHead2 TeXHead2 arrows3 NoMargin3 BeginMargin3
 @c  LocalWords:  EndMargin3 Margin3 Margins3 BeginPenMargin2 xaxis3
 @c  LocalWords:  EndPenMargin2 PenMargin2 PenMargins2 BeginPenMargin3
 @c  LocalWords:  EndPenMargin3 PenMargin3 PenMargins3 BeginDotMargin3
-@c  LocalWords:  EndDotMargin3 DotMargin3 DotMargins3 TrueMargin3
+@c  LocalWords:  EndDotMargin3 DotMargin3 DotMargins3 TrueMargin3 3D
 @c  LocalWords:  yaxis3 zaxis3 ticks3 NoTicks3 arrowbar3 type2 axis3
-@c  LocalWords:  generalaxis3 vectorfield3 margin3 grid3xyz 5unit
-@c  LocalWords:  slopefield1 144x144
+@c  LocalWords:  generalaxis3 vectorfield3 margin3 grid3xyz 5unit 2D
+@c  LocalWords:  slopefield1 144x144 1filll 'load 'asy 'lasy 'auto 4g
+@c  LocalWords:  5bp 1cm 2S 100pt 3t bracedefaultratio incircle 12pt
+@c  LocalWords:  5mm 25cm 3x 5x 3y 602e 2x 2y 3sin 10cm 204e 10x Ai
+@c  LocalWords:  Ai Ai Ai Ai Ai Ai Ai 5E 5cm 2N 2E 2n 100d 5z 5y
+@c  LocalWords:  5unit 144x144
diff --git a/Build/source/utils/asymptote/doc/externalprc.tex b/Build/source/utils/asymptote/doc/externalprc.tex
index e6d4ade1dcf..d131eebd426 100644
--- a/Build/source/utils/asymptote/doc/externalprc.tex
+++ b/Build/source/utils/asymptote/doc/externalprc.tex
@@ -1,12 +1,13 @@
 % Generate inline PRC images for latex with
-% asy -inlineimage teapot -render=4
+% asy -inlineimage cube -render=4
 %
 % Generate inline PRC images for pdflatex with
-% asy -inlineimage teapot -render=4 -tex pdflatex
+% asy -inlineimage cube -render=4 -tex pdflatex
 %
 \documentclass[12pt]{article}
-\input teapot.pre
+\input cube.pre
+\usepackage[bigfiles,noplaybutton]{media9}
 \RequirePackage{color,graphicx}
 \begin{document}
-\input teapot.tex
+\input cube.tex
 \end{document}
diff --git a/Build/source/utils/asymptote/doc/install-sh b/Build/source/utils/asymptote/doc/install-sh
index 04367377519..6781b987bdb 100755
--- a/Build/source/utils/asymptote/doc/install-sh
+++ b/Build/source/utils/asymptote/doc/install-sh
@@ -1,7 +1,7 @@
 #!/bin/sh
 # install - install a program, script, or datafile
 
-scriptversion=2013-10-30.23; # UTC
+scriptversion=2009-04-28.21; # UTC
 
 # This originates from X11R5 (mit/util/scripts/install.sh), which was
 # later released in X11R6 (xc/config/util/install.sh) with the
@@ -35,21 +35,25 @@ scriptversion=2013-10-30.23; # UTC
 # FSF changes to this file are in the public domain.
 #
 # Calling this script install-sh is preferred over install.sh, to prevent
-# 'make' implicit rules from creating a file called install from it
+# `make' implicit rules from creating a file called install from it
 # when there is no Makefile.
 #
 # This script is compatible with the BSD install script, but was written
 # from scratch.
 
-tab='	'
 nl='
 '
-IFS=" $tab$nl"
+IFS=" ""	$nl"
 
-# Set DOITPROG to "echo" to test this script.
+# set DOITPROG to echo to test this script
 
+# Don't use :- since 4.3BSD and earlier shells don't like it.
 doit=${DOITPROG-}
-doit_exec=${doit:-exec}
+if test -z "$doit"; then
+  doit_exec=exec
+else
+  doit_exec=$doit
+fi
 
 # Put in absolute file names if you don't have them in your path;
 # or use environment vars.
@@ -64,6 +68,17 @@ mvprog=${MVPROG-mv}
 rmprog=${RMPROG-rm}
 stripprog=${STRIPPROG-strip}
 
+posix_glob='?'
+initialize_posix_glob='
+  test "$posix_glob" != "?" || {
+    if (set -f) 2>/dev/null; then
+      posix_glob=
+    else
+      posix_glob=:
+    fi
+  }
+'
+
 posix_mkdir=
 
 # Desired mode of installed file.
@@ -122,39 +137,36 @@ while test $# -ne 0; do
     -d) dir_arg=true;;
 
     -g) chgrpcmd="$chgrpprog $2"
-        shift;;
+	shift;;
 
     --help) echo "$usage"; exit $?;;
 
     -m) mode=$2
-        case $mode in
-          *' '* | *"$tab"* | *"$nl"* | *'*'* | *'?'* | *'['*)
-            echo "$0: invalid mode: $mode" >&2
-            exit 1;;
-        esac
-        shift;;
+	case $mode in
+	  *' '* | *'	'* | *'
+'*	  | *'*'* | *'?'* | *'['*)
+	    echo "$0: invalid mode: $mode" >&2
+	    exit 1;;
+	esac
+	shift;;
 
     -o) chowncmd="$chownprog $2"
-        shift;;
+	shift;;
 
     -s) stripcmd=$stripprog;;
 
     -t) dst_arg=$2
-        # Protect names problematic for 'test' and other utilities.
-        case $dst_arg in
-          -* | [=\(\)!]) dst_arg=./$dst_arg;;
-        esac
-        shift;;
+	shift;;
 
     -T) no_target_directory=true;;
 
     --version) echo "$0 $scriptversion"; exit $?;;
 
-    --) shift
-        break;;
+    --)	shift
+	break;;
 
-    -*) echo "$0: invalid option: $1" >&2
-        exit 1;;
+    -*)	echo "$0: invalid option: $1" >&2
+	exit 1;;
 
     *)  break;;
   esac
@@ -174,10 +186,6 @@ if test $# -ne 0 && test -z "$dir_arg$dst_arg"; then
     fi
     shift # arg
     dst_arg=$arg
-    # Protect names problematic for 'test' and other utilities.
-    case $dst_arg in
-      -* | [=\(\)!]) dst_arg=./$dst_arg;;
-    esac
   done
 fi
 
@@ -186,17 +194,13 @@ if test $# -eq 0; then
     echo "$0: no input file specified." >&2
     exit 1
   fi
-  # It's OK to call 'install-sh -d' without argument.
+  # It's OK to call `install-sh -d' without argument.
   # This can happen when creating conditional directories.
   exit 0
 fi
 
 if test -z "$dir_arg"; then
-  do_exit='(exit $ret); exit $ret'
-  trap "ret=129; $do_exit" 1
-  trap "ret=130; $do_exit" 2
-  trap "ret=141; $do_exit" 13
-  trap "ret=143; $do_exit" 15
+  trap '(exit $?); exit' 1 2 13 15
 
   # Set umask so as not to create temps with too-generous modes.
   # However, 'strip' requires both read and write access to temps.
@@ -207,16 +211,16 @@ if test -z "$dir_arg"; then
 
     *[0-7])
       if test -z "$stripcmd"; then
-        u_plus_rw=
+	u_plus_rw=
       else
-        u_plus_rw='% 200'
+	u_plus_rw='% 200'
       fi
       cp_umask=`expr '(' 777 - $mode % 1000 ')' $u_plus_rw`;;
     *)
       if test -z "$stripcmd"; then
-        u_plus_rw=
+	u_plus_rw=
       else
-        u_plus_rw=,u+rw
+	u_plus_rw=,u+rw
       fi
       cp_umask=$mode$u_plus_rw;;
   esac
@@ -224,9 +228,9 @@ fi
 
 for src
 do
-  # Protect names problematic for 'test' and other utilities.
+  # Protect names starting with `-'.
   case $src in
-    -* | [=\(\)!]) src=./$src;;
+    -*) src=./$src;;
   esac
 
   if test -n "$dir_arg"; then
@@ -248,20 +252,51 @@ do
       echo "$0: no destination specified." >&2
       exit 1
     fi
+
     dst=$dst_arg
+    # Protect names starting with `-'.
+    case $dst in
+      -*) dst=./$dst;;
+    esac
 
     # If destination is a directory, append the input filename; won't work
     # if double slashes aren't ignored.
     if test -d "$dst"; then
       if test -n "$no_target_directory"; then
-        echo "$0: $dst_arg: Is a directory" >&2
-        exit 1
+	echo "$0: $dst_arg: Is a directory" >&2
+	exit 1
       fi
       dstdir=$dst
       dst=$dstdir/`basename "$src"`
       dstdir_status=0
     else
-      dstdir=`dirname "$dst"`
+      # Prefer dirname, but fall back on a substitute if dirname fails.
+      dstdir=`
+	(dirname "$dst") 2>/dev/null ||
+	expr X"$dst" : 'X\(.*[^/]\)//*[^/][^/]*/*$' \| \
+	     X"$dst" : 'X\(//\)[^/]' \| \
+	     X"$dst" : 'X\(//\)$' \| \
+	     X"$dst" : 'X\(/\)' \| . 2>/dev/null ||
+	echo X"$dst" |
+	    sed '/^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\/\)[^/].*/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\/\)$/{
+		   s//\1/
+		   q
+		 }
+		 /^X\(\/\).*/{
+		   s//\1/
+		   q
+		 }
+		 s/.*/./; q'
+      `
+
       test -d "$dstdir"
       dstdir_status=$?
     fi
@@ -272,74 +307,74 @@ do
   if test $dstdir_status != 0; then
     case $posix_mkdir in
       '')
-        # Create intermediate dirs using mode 755 as modified by the umask.
-        # This is like FreeBSD 'install' as of 1997-10-28.
-        umask=`umask`
-        case $stripcmd.$umask in
-          # Optimize common cases.
-          *[2367][2367]) mkdir_umask=$umask;;
-          .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
-
-          *[0-7])
-            mkdir_umask=`expr $umask + 22 \
-              - $umask % 100 % 40 + $umask % 20 \
-              - $umask % 10 % 4 + $umask % 2
-            `;;
-          *) mkdir_umask=$umask,go-w;;
-        esac
-
-        # With -d, create the new directory with the user-specified mode.
-        # Otherwise, rely on $mkdir_umask.
-        if test -n "$dir_arg"; then
-          mkdir_mode=-m$mode
-        else
-          mkdir_mode=
-        fi
-
-        posix_mkdir=false
-        case $umask in
-          *[123567][0-7][0-7])
-            # POSIX mkdir -p sets u+wx bits regardless of umask, which
-            # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
-            ;;
-          *)
-            tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
-            trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
-
-            if (umask $mkdir_umask &&
-                exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
-            then
-              if test -z "$dir_arg" || {
-                   # Check for POSIX incompatibilities with -m.
-                   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
-                   # other-writable bit of parent directory when it shouldn't.
-                   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
-                   ls_ld_tmpdir=`ls -ld "$tmpdir"`
-                   case $ls_ld_tmpdir in
-                     d????-?r-*) different_mode=700;;
-                     d????-?--*) different_mode=755;;
-                     *) false;;
-                   esac &&
-                   $mkdirprog -m$different_mode -p -- "$tmpdir" && {
-                     ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
-                     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
-                   }
-                 }
-              then posix_mkdir=:
-              fi
-              rmdir "$tmpdir/d" "$tmpdir"
-            else
-              # Remove any dirs left behind by ancient mkdir implementations.
-              rmdir ./$mkdir_mode ./-p ./-- 2>/dev/null
-            fi
-            trap '' 0;;
-        esac;;
+	# Create intermediate dirs using mode 755 as modified by the umask.
+	# This is like FreeBSD 'install' as of 1997-10-28.
+	umask=`umask`
+	case $stripcmd.$umask in
+	  # Optimize common cases.
+	  *[2367][2367]) mkdir_umask=$umask;;
+	  .*0[02][02] | .[02][02] | .[02]) mkdir_umask=22;;
+
+	  *[0-7])
+	    mkdir_umask=`expr $umask + 22 \
+	      - $umask % 100 % 40 + $umask % 20 \
+	      - $umask % 10 % 4 + $umask % 2
+	    `;;
+	  *) mkdir_umask=$umask,go-w;;
+	esac
+
+	# With -d, create the new directory with the user-specified mode.
+	# Otherwise, rely on $mkdir_umask.
+	if test -n "$dir_arg"; then
+	  mkdir_mode=-m$mode
+	else
+	  mkdir_mode=
+	fi
+
+	posix_mkdir=false
+	case $umask in
+	  *[123567][0-7][0-7])
+	    # POSIX mkdir -p sets u+wx bits regardless of umask, which
+	    # is incompatible with FreeBSD 'install' when (umask & 300) != 0.
+	    ;;
+	  *)
+	    tmpdir=${TMPDIR-/tmp}/ins$RANDOM-$$
+	    trap 'ret=$?; rmdir "$tmpdir/d" "$tmpdir" 2>/dev/null; exit $ret' 0
+
+	    if (umask $mkdir_umask &&
+		exec $mkdirprog $mkdir_mode -p -- "$tmpdir/d") >/dev/null 2>&1
+	    then
+	      if test -z "$dir_arg" || {
+		   # Check for POSIX incompatibilities with -m.
+		   # HP-UX 11.23 and IRIX 6.5 mkdir -m -p sets group- or
+		   # other-writeable bit of parent directory when it shouldn't.
+		   # FreeBSD 6.1 mkdir -m -p sets mode of existing directory.
+		   ls_ld_tmpdir=`ls -ld "$tmpdir"`
+		   case $ls_ld_tmpdir in
+		     d????-?r-*) different_mode=700;;
+		     d????-?--*) different_mode=755;;
+		     *) false;;
+		   esac &&
+		   $mkdirprog -m$different_mode -p -- "$tmpdir" && {
+		     ls_ld_tmpdir_1=`ls -ld "$tmpdir"`
+		     test "$ls_ld_tmpdir" = "$ls_ld_tmpdir_1"
+		   }
+		 }
+	      then posix_mkdir=:
+	      fi
+	      rmdir "$tmpdir/d" "$tmpdir"
+	    else
+	      # Remove any dirs left behind by ancient mkdir implementations.
+	      rmdir ./$mkdir_mode ./-p ./-- 2>/dev/null
+	    fi
+	    trap '' 0;;
+	esac;;
     esac
 
     if
       $posix_mkdir && (
-        umask $mkdir_umask &&
-        $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir"
+	umask $mkdir_umask &&
+	$doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir"
       )
     then :
     else
@@ -349,51 +384,53 @@ do
       # directory the slow way, step by step, checking for races as we go.
 
       case $dstdir in
-        /*) prefix='/';;
-        [-=\(\)!]*) prefix='./';;
-        *)  prefix='';;
+	/*) prefix='/';;
+	-*) prefix='./';;
+	*)  prefix='';;
       esac
 
+      eval "$initialize_posix_glob"
+
       oIFS=$IFS
       IFS=/
-      set -f
+      $posix_glob set -f
       set fnord $dstdir
       shift
-      set +f
+      $posix_glob set +f
       IFS=$oIFS
 
       prefixes=
 
       for d
       do
-        test X"$d" = X && continue
-
-        prefix=$prefix$d
-        if test -d "$prefix"; then
-          prefixes=
-        else
-          if $posix_mkdir; then
-            (umask=$mkdir_umask &&
-             $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
-            # Don't fail if two instances are running concurrently.
-            test -d "$prefix" || exit 1
-          else
-            case $prefix in
-              *\'*) qprefix=`echo "$prefix" | sed "s/'/'\\\\\\\\''/g"`;;
-              *) qprefix=$prefix;;
-            esac
-            prefixes="$prefixes '$qprefix'"
-          fi
-        fi
-        prefix=$prefix/
+	test -z "$d" && continue
+
+	prefix=$prefix$d
+	if test -d "$prefix"; then
+	  prefixes=
+	else
+	  if $posix_mkdir; then
+	    (umask=$mkdir_umask &&
+	     $doit_exec $mkdirprog $mkdir_mode -p -- "$dstdir") && break
+	    # Don't fail if two instances are running concurrently.
+	    test -d "$prefix" || exit 1
+	  else
+	    case $prefix in
+	      *\'*) qprefix=`echo "$prefix" | sed "s/'/'\\\\\\\\''/g"`;;
+	      *) qprefix=$prefix;;
+	    esac
+	    prefixes="$prefixes '$qprefix'"
+	  fi
+	fi
+	prefix=$prefix/
       done
 
       if test -n "$prefixes"; then
-        # Don't fail if two instances are running concurrently.
-        (umask $mkdir_umask &&
-         eval "\$doit_exec \$mkdirprog $prefixes") ||
-          test -d "$dstdir" || exit 1
-        obsolete_mkdir_used=true
+	# Don't fail if two instances are running concurrently.
+	(umask $mkdir_umask &&
+	 eval "\$doit_exec \$mkdirprog $prefixes") ||
+	  test -d "$dstdir" || exit 1
+	obsolete_mkdir_used=true
       fi
     fi
   fi
@@ -428,12 +465,15 @@ do
 
     # If -C, don't bother to copy if it wouldn't change the file.
     if $copy_on_change &&
-       old=`LC_ALL=C ls -dlL "$dst"     2>/dev/null` &&
-       new=`LC_ALL=C ls -dlL "$dsttmp"  2>/dev/null` &&
-       set -f &&
+       old=`LC_ALL=C ls -dlL "$dst"	2>/dev/null` &&
+       new=`LC_ALL=C ls -dlL "$dsttmp"	2>/dev/null` &&
+
+       eval "$initialize_posix_glob" &&
+       $posix_glob set -f &&
        set X $old && old=:$2:$4:$5:$6 &&
        set X $new && new=:$2:$4:$5:$6 &&
-       set +f &&
+       $posix_glob set +f &&
+
        test "$old" = "$new" &&
        $cmpprog "$dst" "$dsttmp" >/dev/null 2>&1
     then
@@ -446,24 +486,24 @@ do
       # to itself, or perhaps because mv is so ancient that it does not
       # support -f.
       {
-        # Now remove or move aside any old file at destination location.
-        # We try this two ways since rm can't unlink itself on some
-        # systems and the destination file might be busy for other
-        # reasons.  In this case, the final cleanup might fail but the new
-        # file should still install successfully.
-        {
-          test ! -f "$dst" ||
-          $doit $rmcmd -f "$dst" 2>/dev/null ||
-          { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
-            { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
-          } ||
-          { echo "$0: cannot unlink or rename $dst" >&2
-            (exit 1); exit 1
-          }
-        } &&
-
-        # Now rename the file to the real destination.
-        $doit $mvcmd "$dsttmp" "$dst"
+	# Now remove or move aside any old file at destination location.
+	# We try this two ways since rm can't unlink itself on some
+	# systems and the destination file might be busy for other
+	# reasons.  In this case, the final cleanup might fail but the new
+	# file should still install successfully.
+	{
+	  test ! -f "$dst" ||
+	  $doit $rmcmd -f "$dst" 2>/dev/null ||
+	  { $doit $mvcmd -f "$dst" "$rmtmp" 2>/dev/null &&
+	    { $doit $rmcmd -f "$rmtmp" 2>/dev/null; :; }
+	  } ||
+	  { echo "$0: cannot unlink or rename $dst" >&2
+	    (exit 1); exit 1
+	  }
+	} &&
+
+	# Now rename the file to the real destination.
+	$doit $mvcmd "$dsttmp" "$dst"
       }
     fi || exit 1
 
diff --git a/Build/source/utils/asymptote/doc/latexmkrc_asydir b/Build/source/utils/asymptote/doc/latexmkrc_asydir
new file mode 100644
index 00000000000..043084e8e6d
--- /dev/null
+++ b/Build/source/utils/asymptote/doc/latexmkrc_asydir
@@ -0,0 +1,4 @@
+sub asy {return system("asy -o asy/ '$_[0]'");}
+add_cus_dep("asy","eps",0,"asy");
+add_cus_dep("asy","pdf",0,"asy");
+add_cus_dep("asy","tex",0,"asy");
diff --git a/Build/source/utils/asymptote/doc/png/Makefile.in b/Build/source/utils/asymptote/doc/png/Makefile.in
index 38b92bc03d1..6ca327d1fe9 100644
--- a/Build/source/utils/asymptote/doc/png/Makefile.in
+++ b/Build/source/utils/asymptote/doc/png/Makefile.in
@@ -26,6 +26,9 @@ asymptote.info: $(SOURCE)
 info:	$(SOURCE) $(ASYFILES:.asy=.png) latexusage.png
 	makeinfo --no-split ../asymptote
 
+../options:
+	cd .. && $(MAKE) options
+
 html:	index.html
 
 clean: FORCE
diff --git a/Build/source/utils/asymptote/doc/png/asymptote.info b/Build/source/utils/asymptote/doc/png/asymptote.info
deleted file mode 100644
index 8cf9caabdac..00000000000
--- a/Build/source/utils/asymptote/doc/png/asymptote.info
+++ /dev/null
@@ -1,9959 +0,0 @@
-This is asymptote.info, produced by makeinfo version 4.13 from
-../asymptote.texi.
-
-This file documents `Asymptote', version 2.23.
-
-   `http://asymptote.sourceforge.net'
-
-   Copyright (C) 2004-13 Andy Hammerlindl, John Bowman, and Tom Prince.
-
-     Permission is granted to copy, distribute and/or modify this
-     document under the terms of the GNU Lesser General Public License
-     (see the file LICENSE in the top-level source directory).
-
-
-INFO-DIR-SECTION Languages
-START-INFO-DIR-ENTRY
-* asymptote: (asymptote/asymptote). Vector graphics language.
-END-INFO-DIR-ENTRY
-
-
-File: asymptote.info,  Node: Top,  Next: Description,  Up: (dir)
-
-Asymptote
-*********
-
-This file documents `Asymptote', version 2.23.
-
-   `http://asymptote.sourceforge.net'
-
-   Copyright (C) 2004-13 Andy Hammerlindl, John Bowman, and Tom Prince.
-
-     Permission is granted to copy, distribute and/or modify this
-     document under the terms of the GNU Lesser General Public License
-     (see the file LICENSE in the top-level source directory).
-
-
-* Menu:
-
-* Description::                 What is `Asymptote'?
-* Installation::                Downloading and installing
-* Tutorial::                    Getting started
-* Drawing commands::            Four primitive graphics commands
-* Bezier curves::               Path connectors and direction specifiers
-* Programming::                 The `Asymptote' vector graphics language
-* LaTeX usage::                 Embedding `Asymptote' commands within `LaTeX'
-* Base modules::                Base modules shipped with `Asymptote'
-* Options::                     Command-line options
-* Interactive mode::            Typing `Asymptote' commands interactively
-* GUI::                         Graphical user interface
-* PostScript to Asymptote::     `Asymptote' backend to `pstoedit'
-* Help::                        Where to get help and submit bug reports
-* Debugger::                    Squish those bugs!
-* Credits::                     Contributions and acknowledgments
-* Index::                       General index
-
- --- The Detailed Node Listing ---
-
-Installation
-
-* UNIX binary distributions::   Prebuilt `UNIX' binaries
-* MacOS X binary distributions::  Prebuilt `MacOS X' binaries
-* Microsoft Windows::           Prebuilt `Microsoft Windows' binary
-* Configuring::                 Configuring `Asymptote' for your system
-* Search paths::                Where `Asymptote' looks for your files
-* Compiling from UNIX source::  Building `Asymptote' from scratch
-* Editing modes::               Convenient `emacs' and `vim' modes
-* Subversion::                  Getting the latest development source
-* Uninstall::                   Goodbye, `Asymptote'!
-
-Drawing commands
-
-* draw::                        Draw a path on a picture or frame
-* fill::                        Fill a cyclic path on a picture or frame
-* clip::                        Clip a picture or frame to a cyclic path
-* label::                       Label a point on a picture
-
-Programming
-
-* Data types::                  void, bool, int, real, pair, triple, string
-* Paths and guides::
-* Pens::                        Colors, line types, line widths, font sizes
-* Transforms::                  Affine transforms
-* Frames and pictures::         Canvases for immediate and deferred drawing
-* Files::                       Reading and writing your data
-* Variable initializers::       Initialize your variables
-* Structures::                  Organize your data
-* Operators::                   Arithmetic and logical operators
-* Implicit scaling::            Avoiding those ugly *s
-* Functions::                   Traditional and high-order functions
-* Arrays::                      Dynamic vectors
-* Casts::                       Implicit and explicit casts
-* Import::                      Importing external `Asymptote' modules
-* Static::                      Where to allocate your variable?
-
-Operators
-
-* Arithmetic & logical::        Basic mathematical operators
-* Self & prefix operators::     Increment and decrement
-* User-defined operators::      Overloading operators
-
-Functions
-
-* Default arguments::           Default values can appear anywhere
-* Named arguments::             Assigning function arguments by keyword
-* Rest arguments::              Functions with a variable number of arguments
-* Mathematical functions::      Standard libm functions
-
-
-Arrays
-
-* Slices::                      Python-style array slices
-
-Base modules
-
-* plain::                       Default `Asymptote' base file
-* simplex::                     Linear programming: simplex method
-* math::                        Extend `Asymptote''s math capabilities
-* interpolate::                 Interpolation routines
-* geometry::                    Geometry routines
-* trembling::                   Wavy lines
-* stats::                       Statistics routines and histograms
-* patterns::                    Custom fill and draw patterns
-* markers::                     Custom path marker routines
-* tree::                        Dynamic binary search tree
-* binarytree::                  Binary tree drawing module
-* drawtree::                    Tree drawing module
-* syzygy::                      Syzygy and braid drawing module
-* feynman::                     Feynman diagrams
-* roundedpath::                 Round the sharp corners of paths
-* animation::                   Embedded PDF and MPEG movies
-* embed::                       Embedding movies, sounds, and 3D objects
-* slide::                       Making presentations with `Asymptote'
-* MetaPost::                    `MetaPost' compatibility routines
-* unicode::                     Accept `unicode' (UTF-8) characters
-* latin1::                      Accept `ISO 8859-1' characters
-* babel::                       Interface to `LaTeX' `babel' package
-* labelpath::                   Drawing curved labels
-* labelpath3::                  Drawing curved labels in 3D
-* annotate::                    Annotate your PDF files
-* CAD::                         2D CAD pen and measurement functions (DIN 15)
-* graph::                       2D linear & logarithmic graphs
-* palette::                     Color density images and palettes
-* three::                       3D vector graphics
-* obj::                         3D obj files
-* graph3::                      3D linear & logarithmic graphs
-* grid3::                       3D grids
-* solids::                      3D solid geometry
-* tube::                        3D rotation minimizing tubes
-* flowchart::                   Flowchart drawing routines
-* contour::                     Contour lines
-* contour3::                    Contour surfaces
-* slopefield::                  Slope fields
-* ode::                         Ordinary differential equations
-
-Graphical User Interface
-
-* GUI installation::            Installing `xasy'
-* GUI usage::
-
-
-File: asymptote.info,  Node: Description,  Next: Installation,  Prev: Top,  Up: Top
-
-1 Description
-*************
-
-`Asymptote' is a powerful descriptive vector graphics language that
-provides a mathematical coordinate-based framework for technical
-drawings.  Labels and equations are typeset with `LaTeX', for overall
-document consistency, yielding the same high-quality level of
-typesetting that `LaTeX' provides for scientific text. By default it
-produces `PostScript' output, but it can also generate any format that
-the `ImageMagick' package can produce.
-
-   A major advantage of `Asymptote' over other graphics packages is
-that it is a high-level programming language, as opposed to just a
-graphics program: it can therefore exploit the best features of the
-script (command-driven) and graphical-user-interface (GUI) methods for
-producing figures. The rudimentary GUI `xasy' included with the package
-allows one to move script-generated objects around. To make `Asymptote'
-accessible to the average user, this GUI is currently being developed
-into a full-fledged interface that can generate objects directly.
-However, the script portion of the language is now ready for general
-use by users who are willing to learn a few simple `Asymptote' graphics
-commands (*note Drawing commands::).
-
-   `Asymptote' is mathematically oriented (e.g. one can use complex
-multiplication to rotate a vector) and uses `LaTeX' to do the
-typesetting of labels. This is an important feature for scientific
-applications. It was inspired by an earlier drawing program (with a
-weaker syntax and capabilities) called `MetaPost'.
-
-   The `Asymptote' vector graphics language provides:
-
-   * a standard for typesetting mathematical figures, just as
-     TeX/`LaTeX' is the de-facto standard for typesetting equations.
-
-   * `LaTeX' typesetting of labels, for overall document consistency;
-
-   * the ability to generate and embed 3D vector PRC graphics within
-     PDF files;
-
-   * a natural coordinate-based framework for technical drawings,
-     inspired by `MetaPost', with a much cleaner, powerful C++-like
-     programming syntax;
-
-   * compilation of figures into virtual machine code for speed, without
-     sacrificing portability;
-
-   * the power of a script-based language coupled to the convenience of
-     a GUI;
-
-   * customization using its own C++-like graphics programming language;
-
-   * sensible defaults for graphical features, with the ability to
-     override;
-
-   * a high-level mathematically oriented interface to the `PostScript'
-     language for vector graphics, including affine transforms and
-     complex variables;
-
-   * functions that can create new (anonymous) functions;
-
-   * deferred drawing that uses the simplex method to solve overall size
-     constraint issues between fixed-sized objects (labels and
-     arrowheads) and objects that should scale with figure size;
-
-
-   Many of the features of `Asymptote' are written in the `Asymptote'
-language itself. While the stock version of `Asymptote' is designed for
-mathematics typesetting needs, one can write `Asymptote' modules that
-tailor it to specific applications. A scientific graphing module has
-already been written (*note graph::). Examples of `Asymptote' code and
-output, including animations, are available at
-
-     `http://asymptote.sourceforge.net/gallery/'.
-   Links to many external resources, including an excellent user-written
-`Asymptote' tutorial can be found at
-
-     `http://asymptote.sourceforge.net/links.html'.
-   A quick reference card for `Asymptote' is available at
-
-     `http://asymptote.sourceforge.net/asyRefCard.pdf'.
-
-
-File: asymptote.info,  Node: Installation,  Next: Tutorial,  Prev: Description,  Up: Top
-
-2 Installation
-**************
-
-* Menu:
-
-* UNIX binary distributions::   Prebuilt `UNIX' binaries
-* MacOS X binary distributions::  Prebuilt `MacOS X' binaries
-* Microsoft Windows::           Prebuilt `Microsoft Windows' binary
-* Configuring::                 Configuring `Asymptote' for your system
-* Search paths::                Where `Asymptote' looks for your files
-* Compiling from UNIX source::  Building `Asymptote' from scratch
-* Editing modes::               Convenient `emacs' and `vim' modes
-* Subversion::                  Getting the latest development source
-* Uninstall::                   Goodbye, `Asymptote'!
-
-   After following the instructions for your specific distribution,
-please see also *note Configuring::.
-
-We recommend subscribing to new release announcements at
-
-     `http://freshmeat.net/projects/asy'
-   Users may also wish to monitor the `Asymptote' forum:
-
-     `http://sourceforge.net/projects/asymptote/forums/forum/409349'
-
-
-File: asymptote.info,  Node: UNIX binary distributions,  Next: MacOS X binary distributions,  Up: Installation
-
-2.1 UNIX binary distributions
-=============================
-
-We release both `tgz' and RPM binary distributions of `Asymptote'. The
-root user can install the `Linux i386' `tgz' distribution of version
-`x.xx' of `Asymptote' with the commands:
-tar -C / -zxf asymptote-x.xx.i386.tgz
-texhash
- The `texhash' command, which installs LaTeX style files, is optional.
-The executable file will be `/usr/local/bin/asy') and example code will
-be installed by default in `/usr/local/share/doc/asymptote/examples'.
-
-Fedora users can easily install the most recent version of `Asymptote'
-with the command
-yum --enablerepo=rawhide install asymptote
-
-To install the latest version of `Asymptote' on a Debian-based
-distribution (e.g. Ubuntu, Mepis, Linspire) follow the instructions for
-compiling from `UNIX' source (*note Compiling from UNIX source::).
-Alternatively, Debian users can install one of Hubert Chan's prebuilt
-`Asymptote' binaries from
-
-     `http://ftp.debian.org/debian/pool/main/a/asymptote'
-
-
-File: asymptote.info,  Node: MacOS X binary distributions,  Next: Microsoft Windows,  Prev: UNIX binary distributions,  Up: Installation
-
-2.2 MacOS X binary distributions
-================================
-
-`MacOS X' users can either compile the `UNIX' source code (*note
-Compiling from UNIX source::) or install the contributed `Asymptote'
-binary available at
-
-`http://www.hmug.org/pub/MacOS_X/X/Applications/Publishing/asymptote/'
-
-Because these preconfigured binary distributions have strict
-architecture and library dependencies that many installations do not
-satisfy, we recommend installing `Asymptote' directly from the official
-source:
-
-   `http://sourceforge.net/project/showfiles.php?group_id=120000'
-
-Note that many `MacOS X' (and FreeBSD) systems lack the GNU `readline'
-library. For full interactive functionality, GNU `readline' version 4.3
-or later must be installed.
-
-
-File: asymptote.info,  Node: Microsoft Windows,  Next: Configuring,  Prev: MacOS X binary distributions,  Up: Installation
-
-2.3 Microsoft Windows
-=====================
-
-Users of the `Microsoft Windows' operating system can install the
-self-extracting `Asymptote' executable `asymptote-x.xx-setup.exe',
-where `x.xx' denotes the latest version.
-
-   A working TeX implementation (such as the one available at
-`http://www.miktex.org') will be required to typeset labels.  You will
-also need to install `GPL Ghostscript' from
-`http://sourceforge.net/projects/ghostscript/'.
-
-   To view the default `PostScript' output, you can install the program
-`gsview' available from `http://www.cs.wisc.edu/~ghost/gsview/'.  A
-better (and free) `PostScript' viewer available at
-`http://psview.sourceforge.net/' (which in particular works properly in
-interactive mode) unfortunately currently requires some manual
-configuration. Specifically, if version `x.xx' of `psview' is extracted
-to the directory `c:\Program Files' one needs to put
-import settings;
-psviewer="c:\Program Files\psview-x.xx\psv.exe";
- in the optional `Asymptote' configuration file; *note configuration
-file::).
-
-   The `ImageMagick' package from
-
-   `http://www.imagemagick.org/script/binary-releases.php'
-
-is required to support output formats other than EPS, PDF, SVG, and PNG
-(*note convert::).  The `Python 2' interpreter from
-`http://www.python.org' is only required if you wish to try out the
-graphical user interface (*note GUI::).
-
-Example code will be installed by default in the `examples'
-subdirectory of the installation directory (by default, `C:\Program
-Files\Asymptote').
-
-
-File: asymptote.info,  Node: Configuring,  Next: Search paths,  Prev: Microsoft Windows,  Up: Installation
-
-2.4 Configuring
-===============
-
-In interactive mode, or when given the `-V' option (the default when
-running `Asymptote' on a single file under `MSDOS'), `Asymptote' will
-automatically invoke the `PostScript' viewer `gv' (under `UNIX') or
-`gsview' (under `MSDOS' to display graphical output. These defaults may
-be overridden with the configuration variable `psviewer'.  The
-`PostScript' viewer should be capable of automatically redrawing
-whenever the output file is updated. The default `UNIX' `PostScript'
-viewer `gv' supports this (via a `SIGHUP' signal). Version `gv-3.6.3'
-or later (from `http://ftp.gnu.org/gnu/gv/') is required for
-interactive mode to work properly.  Users of `ggv' will need to enable
-`Watch file' under `Edit/Postscript Viewer Preferences'.  Users of
-`gsview' will need to enable `Options/Auto Redisplay' (however, under
-`MSDOS' it is still necessary to click on the `gsview' window; under
-`UNIX' one must manually redisplay by pressing the `r' key). A better
-(and free) multiplatform alternative to `gsview' is `psview' (*note
-psview::).
-
-   Configuration variables are most easily set as `Asymptote' variables
-in an optional configuration file `config.asy' *note configuration
-file::).  Here are the default values of several important configuration
-variables under `UNIX':
-
-
-import settings;
-psviewer="gv";
-pdfviewer="acroread";
-gs="gs";
-
-Under `MSDOS', the (installation-dependent) default values of these
-configuration variables are determined automatically from the
-`Microsoft Windows' registry. Viewer settings (such as `psviewer' and
-`pdfviewer') can be set to the string `cmd' to request the application
-normally associated with the corresponding file type.
-
-   For PDF format output, the `gs' setting specifies the location of
-the `PostScript'-to-PDF processor `Ghostscript', available from
-`http://sourceforge.net/projects/ghostscript/'.
-
-   The setting `pdfviewer' specifies the location of the PDF viewer. On
-`UNIX' systems, to support automatic document reloading in `Adobe
-Reader', we recommend copying the file `reload.js' from the `Asymptote'
-system directory (by default, `/usr/local/share/asymptote' under `UNIX'
-to `~/.adobe/Acrobat/x.x/JavaScripts/', where `x.x' represents the
-appropriate `Adobe Reader' version number. The automatic document
-reload feature must then be explicitly enabled by putting
-import settings;
-pdfreload=true;
-pdfreloadOptions="-tempFile";
- in the `Asymptote' configuration file. This reload feature is not
-useful under `MSDOS' since the document cannot be updated anyway on
-that operating system until it is first closed by `Adobe Reader'.
-
-   The configuration variable `dir' can be used to adjust the search
-path (*note Search paths::).
-
-   By default, `Asymptote' attempts to center the figure on the page,
-assuming that the paper type is `letter'. The default paper type may be
-changed to `a4' with the configuration variable `papertype'. Alignment
-to other paper sizes can be obtained by setting the configuration
-variables `paperwidth' and `paperheight'.
-
-   The following configuration variables normally do not require
-adjustment:
-texpath
-texcommand
-dvips
-dvisvgm
-convert
-display
-animate
- Warnings (such as "writeoverloaded") may be enabled or disabled with
-the functions
-warn(string s);
-nowarn(string s);
- or by directly modifying the string array `settings.suppress', which
-lists all disabled warnings.
-
-   Configuration variables may also be set or overwritten with a
-command-line option:
-asy -psviewer=gsview -V venn
-
-   Alternatively, system environment versions of the above configuration
-variables may be set in the conventional way. The corresponding
-environment variable name is obtained by converting the configuration
-variable name to upper case  and prepending `ASYMPTOTE_': for example,
-to set the environment variable
-ASYMPTOTE_PSVIEWER="C:\Program Files\Ghostgum\gsview\gsview32.exe";
- under `Microsoft Windows XP':
-  1. Click on the `Start' button;
-
-  2. Right-click on `My Computer';
-
-  3. Choose `View system information';
-
-  4. Click the `Advanced' tab;
-
-  5. Click the `Environment Variables' button.
-
-
-File: asymptote.info,  Node: Search paths,  Next: Compiling from UNIX source,  Prev: Configuring,  Up: Installation
-
-2.5 Search paths
-================
-
-In looking for `Asymptote' system files, `asy' will search the
-following paths, in the order listed:
-  1. The current directory;
-
-  2. A list of one or more directories specified by the configuration
-     variable `dir' or environment variable `ASYMPTOTE_DIR' (separated
-     by `:' under UNIX and `;' under `MSDOS');
-
-  3. The directory specified by the environment variable
-     `ASYMPTOTE_HOME'; if this variable is not set, the directory
-     `.asy' in the user's home directory (`%USERPROFILE%\.asy' under
-     `MSDOS') is used;
-
-  4. The `Asymptote' system directory (by default,
-     `/usr/local/share/asymptote' under `UNIX' and `C:\Program
-     Files\Asymptote' under `MSDOS').
-
-
-File: asymptote.info,  Node: Compiling from UNIX source,  Next: Editing modes,  Prev: Search paths,  Up: Installation
-
-2.6 Compiling from UNIX source
-==============================
-
-To compile and install a `UNIX' executable from a source release
-`x.xx', first execute the commands:
-gunzip asymptote-x.xx.src.tgz
-tar -xf asymptote-x.xx.src.tar
-cd asymptote-x.xx
- By default the system version of the Boehm garbage collector will be
-used; if it is old we recommend first putting
-`http://www.hpl.hp.com/personal/Hans_Boehm/gc/gc_source/gc-7.2d.tar.gz'
-in the `Asymptote' source directory.
-
-   On `UNIX' platforms (other than `MacOS X'), we recommend using
-version `2.8.1' of the `freeglut' library. To compile `freeglut',
-download
-
-     `http://prdownloads.sourceforge.net/freeglut/freeglut-2.8.1.tar.gz'
-   and type (as the root user):
-gunzip freeglut-2.8.1.tar.gz
-tar -xf freeglut-2.8.1.tar
-cd freeglut-2.8.1
-./configure --prefix=/usr
-make install
-cd ..
- Then compile `Asymptote' with the commands
-./configure
-make all
-make install
- Be sure to use GNU `make' (on non-GNU systems this command may be
-called `gmake').  To build the documentation, you may need to install
-the `texinfo-tex' package. If you get errors from a broken `texinfo' or
-`pdftex' installation, simply put
-
-     `http://asymptote.sourceforge.net/asymptote.pdf'
-   in the directory `doc' and repeat the command `make all'.
-
-For a (default) system-wide installation, the last command should be
-done as the root user. To install without root privileges, change the
-`./configure' command to
-./configure --prefix=$HOME/asymptote
- One can disable use of the Boehm garbage collector by configuring with
-`./configure --disable-gc'. For a list of other configuration options,
-say `./configure --help'. For example, one can tell configure to look
-for header files and libraries in nonstandard locations:
-./configure CFLAGS=-I/opt/usr/include LDFLAGS=-L/opt/usr/lib
-
-   If you are compiling `Asymptote' with `gcc', you will need a
-relatively recent version (e.g. 3.4.4 or later).  For full interactive
-functionality, you will need version 4.3 or later of the GNU `readline'
-library.  The file `gcc3.3.2curses.patch' in the `patches' directory can
-be used to patch the broken curses.h header file (or a local copy
-thereof in the current directory) on some `AIX' and `IRIX' systems.
-
-   The `FFTW' library is only required if you want `Asymptote' to be
-able to take Fourier transforms of data (say, to compute an audio power
-spectrum). The `GSL' library is only required if you require the
-special functions that it supports.
-
-   If you don't want to install `Asymptote' system wide, just make sure
-the compiled binary `asy' and GUI script `xasy' are in your path and
-set the configuration variable `dir' to point to the directory `base'
-(in the top level directory of the `Asymptote' source code).
-
-
-File: asymptote.info,  Node: Editing modes,  Next: Subversion,  Prev: Compiling from UNIX source,  Up: Installation
-
-2.7 Editing modes
-=================
-
-Users of `emacs' can edit `Asymptote' code with the mode `asy-mode',
-after enabling it by putting the following lines in their `.emacs'
-initialization file, replacing `ASYDIR' with the location of the
-`Asymptote' system directory (by default, `/usr/local/share/asymptote'
-or `C:\Program Files\Asymptote' under `MSDOS'):
-(add-to-list 'load-path "ASYDIR")
-(autoload 'asy-mode "asy-mode.el" "Asymptote major mode." t)
-(autoload 'lasy-mode "asy-mode.el" "hybrid Asymptote/Latex major mode." t)
-(autoload 'asy-insinuate-latex "asy-mode.el" "Asymptote insinuate LaTeX." t)
-(add-to-list 'auto-mode-alist '("\\.asy$" . asy-mode))
-
- Particularly useful key bindings in this mode are `C-c C-c', which
-compiles and displays the current buffer, and the key binding `C-c ?',
-which shows the available function prototypes for the command at the
-cursor.  For full functionality you should also install the Apache
-Software Foundation package `two-mode-mode':
-
-     `http://www.dedasys.com/freesoftware/files/two-mode-mode.el'
-   Once installed, you can use the hybrid mode `lasy-mode' to edit a
-LaTeX file containing embedded `Asymptote' code (*note LaTeX usage::).
-This mode can be enabled within `latex-mode' with the key sequence `M-x
-lasy-mode <RET>'.  On `UNIX' systems, additional keywords will be
-generated from all `asy' files in the space-separated list of
-directories specified by the environment variable `ASYMPTOTE_SITEDIR'.
-Further documentation of `asy-mode' is available within `emacs' by
-pressing the sequence keys `C-h f asy-mode <RET>'.
-
-   Fans of `vim' can customize `vim' for `Asymptote' with
-
-`cp /usr/local/share/asymptote/asy.vim ~/.vim/syntax/asy.vim'
-
-and add the following to their `~/.vimrc' file:
-augroup filetypedetect
-au BufNewFile,BufRead *.asy     setf asy
-augroup END
-filetype plugin on
-
-   If any of these directories or files don't exist, just create them.
-To set `vim' up to run the current asymptote script using `:make' just
-add to `~/.vim/ftplugin/asy.vim':
-setlocal makeprg=asy\ %
-setlocal errorformat=%f:\ %l.%c:\ %m
-
-   Syntax highlighting support for the KDE editor `Kate' can be enabled
-by running `asy-kate.sh' in the `/usr/local/share/asymptote' directory
-and putting the generated `asymptote.xml' file in
-`~/.kde/share/apps/katepart/syntax/'.
-
-
-File: asymptote.info,  Node: Subversion,  Next: Uninstall,  Prev: Editing modes,  Up: Installation
-
-2.8 Subversion (SVN)
-====================
-
-The following commands are needed to install the latest development
-version of `Asymptote' using `Subversion':
-svn co http://asymptote.svn.sourceforge.net/svnroot/asymptote/trunk/asymptote
-cd asymptote
-./autogen.sh
-./configure
-make all
-make install
-
-To compile without optimization, use the command `make CFLAGS=-g'.
-
-
-File: asymptote.info,  Node: Uninstall,  Prev: Subversion,  Up: Installation
-
-2.9 Uninstall
-=============
-
-To uninstall an `Linux i386' binary distribution, use the commands
-tar -zxvf asymptote-x.xx.i386.tgz | xargs --replace=% rm /%
-texhash
-
-To uninstall all `Asymptote' files installed from a source
-distribution, use the command
-make uninstall
-
-
-File: asymptote.info,  Node: Tutorial,  Next: Drawing commands,  Prev: Installation,  Up: Top
-
-3 Tutorial
-**********
-
-3.1 Drawing in batch mode
-=========================
-
-To draw a line from coordinate (0,0) to coordinate (100,100), create a
-text file `test.asy' containing
-
-draw((0,0)--(100,100));
- Then execute the command
-asy -V test
- Alternatively, `MSDOS' users can drag and drop `test.asy' onto the
-Desktop `asy' icon (or make `Asymptote' the default application for the
-extension `asy').
-
-This method, known as _batch mode_, outputs a `PostScript' file
-`test.eps'. If you prefer PDF output, use the command line
-asy -V -f pdf test
- In either case, the `-V' option opens up a viewer window so you can
-immediately view the result:
-
-
-Here, the `--' connector joins the two points `(0,0)' and `(100,100)'
-with a line segment.
-
-3.2 Drawing in interactive mode
-===============================
-
-Another method is _interactive mode_, where `Asymptote' reads
-individual commands as they are entered by the user. To try this out,
-enter `Asymptote''s interactive mode by clicking on the `Asymptote'
-icon or typing the command `asy'.  Then type
-draw((0,0)--(100,100));
- followed by `Enter', to obtain the above image.  At this point you can
-type further `draw' commands, which will be added to the displayed
-figure, `erase' to clear the canvas,
-input test;
- to execute all of the commands contained in the file `test.asy', or
-`quit' to exit interactive mode.  You can use the arrow keys in
-interactive mode to edit previous lines.  The tab key will
-automatically complete unambiguous words; otherwise, hitting tab again
-will show the possible choices. Further commands specific to
-interactive mode are described in *note Interactive mode::.
-
-3.3 Figure size
-===============
-
-In `Asymptote', coordinates like `(0,0)' and `(100,100)', called
-_pairs_, are expressed in `PostScript' "big points" (1 `bp' = 1/72
-`inch') and the default line width is `0.5bp'.  However, it is often
-inconvenient to work directly in `PostScript' coordinates.  The next
-example produces identical output to the previous example, by scaling
-the line `(0,0)--(1,1)' to fit a rectangle of width `100.5 bp' and
-height `100.5 bp' (the extra `0.5bp' accounts for the line width):
-size(100.5,100.5);
-draw((0,0)--(1,1));
-
-
-
-One can also specify the size in `pt' (1 `pt' = 1/72.27 `inch'), `cm',
-`mm', or `inches'.  Two nonzero size arguments (or a single size
-argument) restrict the size in both directions, preserving the aspect
-ratio.  If 0 is given as a size argument, no restriction is made in
-that direction; the overall scaling will be determined by the other
-direction (*note size::):
-
-size(0,100.5);
-draw((0,0)--(2,1),Arrow);
-
-
-
-To connect several points and create a cyclic path, use the `cycle'
-keyword:
-
-size(3cm);
-draw((0,0)--(1,0)--(1,1)--(0,1)--cycle);
-
-
-For convenience, the path `(0,0)--(1,0)--(1,1)--(0,1)--cycle' may be
-replaced with the predefined variable `unitsquare', or equivalently,
-`box((0,0),(1,1))'.
-
-   To make the user coordinates represent multiples of exactly `1cm':
-unitsize(1cm);
-draw(unitsquare);
-
-3.4 Labels
-==========
-
-Adding labels is easy in `Asymptote'; one specifies the label as a
-double-quoted `LaTeX' string, a coordinate, and an optional alignment
-direction:
-
-size(3cm);
-draw(unitsquare);
-label("$A$",(0,0),SW);
-label("$B$",(1,0),SE);
-label("$C$",(1,1),NE);
-label("$D$",(0,1),NW);
-
-
-
-`Asymptote' uses the standard compass directions `E=(1,0)', `N=(0,1)',
-`NE=unit(N+E)', and `ENE=unit(E+NE)', etc., which along with the
-directions `up', `down', `right', and `left' are defined as pairs in
-the `Asymptote' base module `plain' (a user who has a local variable
-named `E' may access the compass direction `E' by prefixing it with the
-name of the module where it is defined: `plain.E').
-
-3.5 Paths
-=========
-
-This example draws a path that approximates a quarter circle,
-terminated with an arrowhead:
-
-size(100,0);
-draw((1,0){up}..{left}(0,1),Arrow);
-
-
-Here the directions `up' and `left' in braces specify the incoming and
-outgoing directions at the points `(1,0)' and `(0,1)', respectively.
-
-   In general, a path is specified as a list of points (or other paths)
-interconnected with `--', which denotes a straight line segment, or
-`..', which denotes a cubic spline (*note Bezier curves::).  Specifying
-a final `..cycle' creates a cyclic path that connects smoothly back to
-the initial node, as in this approximation (accurate to within 0.06%)
-of a unit circle:
-path unitcircle=E..N..W..S..cycle;
-
-An `Asymptote' path, being connected, is equivalent to a `Postscript
-subpath'. The `^^' binary operator, which requests that the pen be
-moved (without drawing or affecting endpoint curvatures) from the final
-point of the left-hand path to the initial point of the right-hand
-path, may be used to group several `Asymptote' paths into a `path[]'
-array (equivalent to a `PostScript' path):
-
-size(0,100);
-path unitcircle=E..N..W..S..cycle;
-path g=scale(2)*unitcircle;
-filldraw(unitcircle^^g,evenodd+yellow,black);
-
-
-
-The `PostScript' even-odd fill rule here specifies that only the region
-bounded between the two unit circles is filled (*note fillrule::).  In
-this example, the same effect can be achieved by using the default zero
-winding number fill rule, if one is careful to alternate the
-orientation of the paths:
-filldraw(unitcircle^^reverse(g),yellow,black);
-
-   The `^^' operator is used by the `box(triple, triple)' function in
-the module `three.asy' to construct the edges of a cube `unitbox'
-without retracing steps (*note three::):
-
-import three;
-
-currentprojection=orthographic(5,4,2,center=true);
-
-size(5cm);
-size3(3cm,5cm,8cm);
-
-draw(unitbox);
-
-dot(unitbox,red);
-
-label("$O$",(0,0,0),NW);
-label("(1,0,0)",(1,0,0),S);
-label("(0,1,0)",(0,1,0),E);
-label("(0,0,1)",(0,0,1),Z);
-
-
-
-See section *note graph:: (or the online `Asymptote' gallery and
-external links posted at `http://asymptote.sourceforge.net') for
-further examples, including two-dimensional and interactive
-three-dimensional scientific graphs. Additional examples have been
-posted by Philippe Ivaldi at `http://www.piprime.fr/asymptote'.  A
-user-written `Asymptote' tutorial is available at
-http://www.artofproblemsolving.com/Wiki/index.php/Asymptote:_Basics
-
-
-File: asymptote.info,  Node: Drawing commands,  Next: Bezier curves,  Prev: Tutorial,  Up: Top
-
-4 Drawing commands
-******************
-
-All of `Asymptote''s graphical capabilities are based on four primitive
-commands. The three `PostScript' drawing commands `draw', `fill', and
-`clip' add objects to a picture in the order in which they are
-executed, with the most recently drawn object appearing on top.  The
-labeling command `label' can be used to add text labels and external
-EPS images, which will appear on top of the `PostScript' objects (since
-this is normally what one wants), but again in the relative order in
-which they were executed. After drawing objects on a picture, the
-picture can be output with the `shipout' function (*note shipout::).
-
-   If you wish to draw `PostScript' objects on top of labels (or
-verbatim `tex' commands; *note tex::), the `layer' command may be used
-to start a new `PostScript/LaTeX' layer:
-void layer(picture pic=currentpicture);
-
-   The `layer' function gives one full control over the order in which
-objects are drawn. Layers are drawn sequentially, with the most recent
-layer appearing on top. Within each layer, labels, images, and verbatim
-`tex' commands are always drawn after the `PostScript' objects in that
-layer.
-
-   While some of these drawing commands take many options, they all
-have sensible default values (for example, the picture argument
-defaults to currentpicture).
-
-* Menu:
-
-* draw::                        Draw a path on a picture or frame
-* fill::                        Fill a cyclic path on a picture or frame
-* clip::                        Clip a picture or frame to a cyclic path
-* label::                       Label a point on a picture
-
-
-File: asymptote.info,  Node: draw,  Next: fill,  Up: Drawing commands
-
-4.1 draw
-========
-
-void draw(picture pic=currentpicture, Label L="", path g,
-          align align=NoAlign, pen p=currentpen,
-          arrowbar arrow=None, arrowbar bar=None, margin margin=NoMargin,
-          Label legend="", marker marker=nomarker);
-
-Draw the path `g' on the picture `pic' using pen `p' for drawing, with
-optional drawing attributes (Label `L', explicit label alignment
-`align', arrows and bars `arrow' and `bar', margins `margin', legend,
-and markers `marker'). Only one parameter, the path, is required. For
-convenience, the arguments `arrow' and `bar' may be specified in either
-order. The argument `legend' is a Label to use in constructing an
-optional legend entry.
-
-   Bars are useful for indicating dimensions. The possible values of
-`bar' are `None', `BeginBar', `EndBar' (or equivalently `Bar'), and
-`Bars' (which draws a bar at both ends of the path). Each of these bar
-specifiers (except for `None') will accept an optional real argument
-that denotes the length of the bar in `PostScript' coordinates. The
-default bar length is `barsize(pen)'.
-
-   The possible values of `arrow' are `None', `Blank' (which draws no
-arrows or path), `BeginArrow', `MidArrow', `EndArrow' (or equivalently
-`Arrow'), and `Arrows' (which draws an arrow at both ends of the path).
-All of the arrow specifiers except for `None' and `Blank' may be given
-the optional arguments arrowhead `arrowhead' (one of the predefined
-arrowhead styles `DefaultHead', `SimpleHead', `HookHead', `TeXHead'),
-real `size' (arrowhead size in `PostScript' coordinates), real `angle'
-(arrowhead angle in degrees), filltype `filltype' (one of `FillDraw',
-`Fill', `NoFill', `UnFill', `Draw') and (except for `MidArrow' and
-`Arrows') a real `position' (in the sense of `point(path p, real t)')
-along the path where the tip of the arrow should be placed. The default
-arrowhead size when drawn with a pen `p' is `arrowsize(p)'. There are
-also arrow versions with slightly modified default values of `size' and
-`angle' suitable for curved arrows: `BeginArcArrow', `EndArcArrow' (or
-equivalently `ArcArrow'), `MidArcArrow', and `ArcArrows'.
-
-   Margins can be used to shrink the visible portion of a path by
-`labelmargin(p)' to avoid overlap with other drawn objects.  Typical
-values of `margin' are `NoMargin', `BeginMargin', `EndMargin' (or
-equivalently `Margin'), and `Margins' (which leaves a margin at both
-ends of the path). One may use `Margin(real begin, real end)' to
-specify the size of the beginning and ending margin, respectively, in
-multiples of the units `labelmargin(p)' used for aligning labels.
-Alternatively, `BeginPenMargin', `EndPenMargin' (or equivalently
-`PenMargin'), `PenMargins', `PenMargin(real begin, real end)' specify a
-margin in units of the pen line width, taking account of the pen line
-width when drawing the path or arrow. For example, use `DotMargin', an
-abbreviation for `PenMargin(-0.5*dotfactor,0.5*dotfactor)', to draw
-from the usual beginning point just up to the boundary of an end dot of
-width `dotfactor*linewidth(p)'.  The qualifiers `BeginDotMargin',
-`EndDotMargin', and `DotMargins' work similarly. The qualifier
-`TrueMargin(real begin, real end)' allows one to specify a margin
-directly in `PostScript' units, independent of the pen line width.
-
-   The use of arrows, bars, and margins is illustrated by the examples
-`Pythagoras.asy', `sqrtx01.asy', and `triads.asy'.
-
-   The legend for a picture `pic' can be fit and aligned to a frame
-with the routine: 
-frame legend(picture pic=currentpicture, int perline=1,
-             real xmargin=legendmargin, real ymargin=xmargin,
-             real linelength=legendlinelength,
-             real hskip=legendhskip, real vskip=legendvskip,
-             real maxwidth=0, real maxheight=0,
-             bool hstretch=false, bool vstretch=false, pen p=currentpen);
- Here `xmargin' and `ymargin' specify the surrounding x and y margins,
-`perline' specifies the number of entries per line (default 1; 0 means
-choose this number automatically), `linelength' specifies the length of
-the path lines, `hskip' and `vskip' specify the line skip (as a
-multiple of the legend entry size), `maxwidth' and `maxheight' specify
-optional upper limits on the width and height of the resulting legend
-(0 means unlimited), `hstretch' and `vstretch' allow the legend to
-stretch horizontally or vertically, and `p' specifies the pen used to
-draw the bounding box. The legend frame can then be added and aligned
-about a point on a picture `dest' using `add' or `attach' (*note add
-about::).
-
-   To draw a dot, simply draw a path containing a single point.  The
-`dot' command defined in the module `plain' draws a dot having a
-diameter equal to an explicit pen line width or the default line width
-magnified by `dotfactor' (6 by default), using the specified filltype
-(*note filltype::):
-void dot(picture pic=currentpicture, pair z, pen p=currentpen,
-         filltype filltype=Fill);
-void dot(picture pic=currentpicture, Label L, pair z, align align=NoAlign,
-         string format=defaultformat, pen p=currentpen, filltype filltype=Fill);
-void dot(picture pic=currentpicture, Label[] L=new Label[], pair[] z,
-         align align=NoAlign, string format=defaultformat, pen p=currentpen,
-         filltype filltype=Fill)
-void dot(picture pic=currentpicture, Label L, pen p=currentpen,
-         filltype filltype=Fill);
-
-   If the variable `Label' is given as the `Label' argument to the
-second routine, the `format' argument will be used to format a string
-based on the dot location (here `defaultformat' is `"$%.4g$"').  The
-third routine draws a dot at every point of a pair array `z'.  One can
-also draw a dot at every node of a path:
-void dot(picture pic=currentpicture, Label[] L=new Label[],
-         path g, align align=RightSide, string format=defaultformat,
-         pen p=currentpen, filltype filltype=Fill);
- See *note pathmarkers:: and *note markers:: for more general methods
-for marking path nodes.
-
-   To draw a fixed-sized object (in `PostScript' coordinates) about the
-user coordinate `origin', use the routine 
-void draw(pair origin, picture pic=currentpicture, Label L="", path g,
-          align align=NoAlign, pen p=currentpen, arrowbar arrow=None,
-          arrowbar bar=None, margin margin=NoMargin, Label legend="",
-          marker marker=nomarker);
-
-
-File: asymptote.info,  Node: fill,  Next: clip,  Prev: draw,  Up: Drawing commands
-
-4.2 fill
-========
-
-void fill(picture pic=currentpicture, path g, pen p=currentpen);
-
-Fill the interior region bounded by the cyclic path `g' on the picture
-`pic', using the pen `p'.
-
-   There is also a convenient `filldraw' command, which fills the path
-and then draws in the boundary. One can specify separate pens for each
-operation:
-void filldraw(picture pic=currentpicture, path g, pen fillpen=currentpen,
-              pen drawpen=currentpen);
-
-   This fixed-size version of `fill' allows one to fill an object
-described in `PostScript' coordinates about the user coordinate
-`origin':
-void fill(pair origin, picture pic=currentpicture, path g, pen p=currentpen);
-
-This is just a convenient abbreviation for the commands:
-picture opic;
-fill(opic,g,p);
-add(pic,opic,origin);
-
-   The routine 
-void filloutside(picture pic=currentpicture, path g, pen p=currentpen);
- fills the region exterior to the path `g', out to the current boundary
-of picture `pic'.
-
-   Lattice gradient shading varying smoothly over a two-dimensional
-array of pens `p', using fill rule `fillrule', can be produced with
-void latticeshade(picture pic=currentpicture, path g, bool stroke=false,
-                  pen fillrule=currentpen, pen[][] p)
- If `stroke=true', the region filled is the same as the region that
-would be drawn by `draw(pic,g,fillrule+zerowinding)'; in this case the
-path `g' need not be cyclic.  The pens in `p' must belong to the same
-color space. One can use the functions `rgb(pen)' or `cmyk(pen)' to
-promote pens to a higher color space, as illustrated in the example file
-`latticeshading.asy'.
-
-   Axial gradient shading varying smoothly from `pena' to `penb' in the
-direction of the line segment `a--b' can be achieved with
-void axialshade(picture pic=currentpicture, path g, bool stroke=false,
-                pen pena, pair a, bool extenda=true,
-                pen penb, pair b, bool extendb=true);
- The boolean parameters `extenda' and `extendb' indicate whether the
-shading should extend beyond the axis endpoints `a' and `b'.
-
-   Radial gradient shading varying smoothly from `pena' on the circle
-with center `a' and radius `ra' to `penb' on the circle with center `b'
-and radius `rb' is similar:
-void radialshade(picture pic=currentpicture, path g, bool stroke=false,
-                 pen pena, pair a, real ra, bool extenda=true,
-                 pen penb, pair b, real rb, bool extendb=true);
- The boolean parameters `extenda' and `extendb' indicate whether the
-shading should extend beyond the radii `a' and `b'.  Illustrations of
-radial shading are provided in the example files `shade.asy',
-`ring.asy', and `shadestroke.asy'.
-
-   Gouraud shading using fill rule `fillrule' and the vertex colors in
-the pen array `p' on a triangular lattice defined by the vertices `z'
-and edge flags `edges' is implemented with
-void gouraudshade(picture pic=currentpicture, path g, bool stroke=false,
-                  pen fillrule=currentpen, pen[] p, pair[] z,
-                  int[] edges);
-void gouraudshade(picture pic=currentpicture, path g, bool stroke=false,
-                  pen fillrule=currentpen, pen[] p, int[] edges);
- In the second form, the elements of `z' are taken to be successive
-nodes of path `g'. The pens in `p' must belong to the same color space.
-Illustrations of Gouraud shading are provided in the example file
-`Gouraud.asy' and in the solid geometry module `solids.asy'.  The edge
-flags used in Gouraud shading are documented here:
-
-     `http://partners.adobe.com/public/developer/en/ps/sdk/TN5600.SmoothShading.pdf'.
-
-   Tensor product shading using fill rule `fillrule' on patches bounded
-by the n cyclic paths of length 4 in path array `b', using the vertex
-colors specified in the n \times 4 pen array `p' and internal control
-points in the n \times 4 array `z', is implemented with
-void tensorshade(picture pic=currentpicture, path g, bool stroke=false,
-                 pen fillrule=currentpen, pen[][] p, path[] b=g,
-                 pair[][] z=new pair[][]);
- If the array `z' is empty, Coons shading, in which the color control
-points are calculated automatically, is used.  The pens in `p' must
-belong to the same color space.  A simpler interface for the case of a
-single patch (n=1) is also available:
-void tensorshade(picture pic=currentpicture, path g, bool stroke=false,
-                 pen fillrule=currentpen, pen[] p, path b=g,
-                 pair[] z=new pair[]);
- One can also smoothly shade the regions between consecutive paths of a
-sequence using a given array of pens:
-void draw(picture pic=currentpicture, pen fillrule=currentpen, path[] g,
-          pen[] p);
- Illustrations of tensor product and Coons shading are provided in the
-example files `tensor.asy', `Coons.asy', `BezierSurface.asy', and
-`rainbow.asy'.
-
-   More general shading possibilities are available with the `pdflatex',
-`context', and `pdftex' TeX engines: the routine
-void functionshade(picture pic=currentpicture, path[] g, bool stroke=false,
-                   pen fillrule=currentpen, string shader);
- shades on picture `pic' the interior of path `g' according to fill
-rule `fillrule' using the `PostScript' calculator routine specified by
-the string `shader'; this routine takes 2 arguments, each in [0,1], and
-returns `colors(fillrule).length' color components.  Function shading
-is illustrated in the example `functionshading.asy'.
-
-   The following routine uses `evenodd' clipping together with the `^^'
-operator to unfill a region:
-
-void unfill(picture pic=currentpicture, path g);
-
-
-File: asymptote.info,  Node: clip,  Next: label,  Prev: fill,  Up: Drawing commands
-
-4.3 clip
-========
-
-void clip(picture pic=currentpicture, path g, stroke=false,
-          pen fillrule=currentpen);
-
-Clip the current contents of picture `pic' to the region bounded by the
-path `g', using fill rule `fillrule' (*note fillrule::).  If
-`stroke=true', the clipped portion is the same as the region that would
-be drawn with `draw(pic,g,fillrule+zerowinding)'; in this case the path
-`g' need not be cyclic. For an illustration of picture clipping, see
-the first example in *note LaTeX usage::.
-
-
-File: asymptote.info,  Node: label,  Prev: clip,  Up: Drawing commands
-
-4.4 label
-=========
-
-void label(picture pic=currentpicture, Label L, pair position,
-           align align=NoAlign, pen p=currentpen, filltype filltype=NoFill)
-
-Draw Label `L' on picture `pic' using pen `p'. If `align' is `NoAlign',
-the label will be centered at user coordinate `position'; otherwise it
-will be aligned in the direction of `align' and displaced from
-`position' by the `PostScript' offset `align*labelmargin(p)'.  The
-constant `Align' can be used to align the bottom-left corner of the
-label at `position'.  The Label `L' can either be a string or the
-structure obtained by calling one of the functions
-Label Label(string s="", pair position, align align=NoAlign,
-            pen p=nullpen, embed embed=Rotate, filltype filltype=NoFill);
-Label Label(string s="", align align=NoAlign,
-            pen p=nullpen, embed embed=Rotate, filltype filltype=NoFill);
-Label Label(Label L, pair position, align align=NoAlign,
-            pen p=nullpen, embed embed=L.embed, filltype filltype=NoFill);
-Label Label(Label L, align align=NoAlign,
-            pen p=nullpen, embed embed=L.embed, filltype filltype=NoFill);
- The text of a Label can be scaled, slanted, rotated, or shifted by
-multiplying it on the left by an affine transform (*note Transforms::).
-For example, `rotate(45)*xscale(2)*L' first scales `L' in the x
-direction and then rotates it counterclockwise by 45 degrees. The final
-position of a Label can also be shifted by a `PostScript' coordinate
-translation: `shift(10,0)*L'.  An explicit pen specified within the
-Label overrides other pen arguments.  The `embed' argument determines
-how the Label should transform with the embedding picture:
-`Shift'
-     only shift with embedding picture;
-
-`Rotate'
-     only shift and rotate with embedding picture (default);
-
-`Rotate(pair z)'
-     rotate with (picture-transformed) vector `z'.
-
-`Slant'
-     only shift, rotate, slant, and reflect with embedding picture;
-
-`Scale'
-     shift, rotate, slant, reflect, and scale with embedding picture.
-
-
-   To add a label to a path, use
-void label(picture pic=currentpicture, Label L, path g, align align=NoAlign,
-           pen p=currentpen, filltype filltype=NoFill);
- By default the label will be positioned at the midpoint of the path.
-An alternative label position (in the sense of `point(path p, real t)')
-may be specified as a real value for `position' in constructing the
-Label. The position `Relative(real)' specifies a location relative to
-the total arclength of the path. These convenient abbreviations are
-predefined: 
-position BeginPoint=Relative(0);
-position MidPoint=Relative(0.5);
-position EndPoint=Relative(1);
-
-   Path labels are aligned in the direction `align', which may be
-specified as an absolute compass direction (pair) or a direction
-`Relative(pair)' measured relative to a north axis in the local
-direction of the path. For convenience `LeftSide', `Center', and
-`RightSide' are defined as `Relative(W)', `Relative((0,0))', and
-`Relative(E)', respectively.  Multiplying `LeftSide', `Center',
-`RightSide' on the left by a real scaling factor will move the label
-further away from or closer to the path.
-
-   A label with a fixed-size arrow of length `arrowlength' pointing to
-`b' from direction `dir' can be produced with the routine 
-void arrow(picture pic=currentpicture, Label L="", pair b, pair dir,
-           real length=arrowlength, align align=NoAlign,
-           pen p=currentpen, arrowbar arrow=Arrow, margin margin=EndMargin);
- If no alignment is specified (either in the Label or as an explicit
-argument), the optional Label will be aligned in the direction `dir',
-using margin `margin'.
-
-   The function `string graphic(string name, string options="")'
-returns a string that can be used to include an encapsulated
-`PostScript' (EPS) file. Here, `name' is the name of the file to
-include and `options' is a string containing a comma-separated list of
-optional bounding box (`bb=llx lly urx ury'), width (`width=value'),
-height (`height=value'), rotation (`angle=value'), scaling
-(`scale=factor'), clipping (`clip=bool'), and draft mode (`draft=bool')
-parameters. The `layer()' function can be used to force future objects
-to be drawn on top of the included image:
-label(graphic("file.eps","width=1cm"),(0,0),NE);
-layer();
-
-   The `string baseline(string s, string template="\strut")' function
-can be used to enlarge the bounding box of labels to match a given
-template, so that their baselines will be typeset on a horizontal line.
-See `Pythagoras.asy' for an example.
-
-   One can prevent labels from overwriting one another with the
-`overwrite' pen attribute (*note overwrite::).
-
-   The structure `object' defined in `plain_Label.asy' allows Labels
-and frames to be treated in a uniform manner.  A group of objects may
-be packed together into single frame with the routine 
-frame pack(pair align=2S ... object inset[]);
- To draw or fill a box (or ellipse or other path) around a Label and
-return the bounding object, use one of the routines
-object draw(picture pic=currentpicture, Label L, envelope e,
-            real xmargin=0, real ymargin=xmargin, pen p=currentpen,
-            filltype filltype=NoFill, bool above=true);
-object draw(picture pic=currentpicture, Label L, envelope e, pair position,
-            real xmargin=0, real ymargin=xmargin, pen p=currentpen,
-            filltype filltype=NoFill, bool above=true);
- Here `envelope' is a boundary-drawing routine such as `box',
-`roundbox', or `ellipse' defined in `plain_boxes.asy' (*note
-envelope::).
-
-   The function `path[] texpath(Label L)' returns the path array that
-TeX would fill to draw the Label `L'.
-
-   The `string minipage(string s, width=100pt)' function can be used to
-format string `s' into a paragraph of width `width'.  This example uses
-`minipage', `clip', and `graphic' to produce a CD label:
-
-
-size(11.7cm,11.7cm);
-asy(nativeformat(),"logo");
-fill(unitcircle^^(scale(2/11.7)*unitcircle),
-     evenodd+rgb(124/255,205/255,124/255));
-label(scale(1.1)*minipage(
-"\centering\scriptsize \textbf{\LARGE {\tt Asymptote}\\
-\smallskip
-\small The Vector Graphics Language}\\
-\smallskip
-\textsc{Andy Hammerlindl, John Bowman, and Tom Prince}
-http://asymptote.sourceforge.net\\
-",8cm),(0,0.6));
-label(graphic("logo."+nativeformat(),"height=7cm"),(0,-0.22));
-clip(unitcircle^^(scale(2/11.7)*unitcircle),evenodd);
-
-
-File: asymptote.info,  Node: Bezier curves,  Next: Programming,  Prev: Drawing commands,  Up: Top
-
-5 Bezier curves
-***************
-
-Each interior node of a cubic spline may be given a direction prefix or
-suffix `{dir}': the direction of the pair `dir' specifies the direction
-of the incoming or outgoing tangent, respectively, to the curve at that
-node. Exterior nodes may be given direction specifiers only on their
-interior side.
-
-   A cubic spline between the node z_0, with postcontrol point c_0, and
-the node z_1, with precontrol point c_1, is computed as the Bezier curve
-
-
-
-As illustrated in the diagram below, the third-order midpoint (m_5)
-constructed from two endpoints z_0 and z_1 and two control points c_0
-and c_1, is the point corresponding to t=1/2 on the Bezier curve formed
-by the quadruple (z_0, c_0, c_1, z_1). This allows one to recursively
-construct the desired curve, by using the newly extracted third-order
-midpoint as an endpoint and the respective second- and first-order
-midpoints as control points:
-
-
-
-Here m_0, m_1 and m_2 are the first-order midpoints, m_3 and m_4 are
-the second-order midpoints, and m_5 is the third-order midpoint.  The
-curve is then constructed by recursively applying the algorithm to
-(z_0, m_0, m_3, m_5) and (m_5, m_4, m_2, z_1).
-
-   In fact, an analogous property holds for points located at any
-fraction t in [0,1] of each segment, not just for midpoints (t=1/2).
-
-   The Bezier curve constructed in this manner has the following
-properties:
-   * It is entirely contained in the convex hull of the given four
-     points.
-
-   * It starts heading from the first endpoint to the first control
-     point and finishes heading from the second control point to the
-     second endpoint.
-
-
-   The user can specify explicit control points between two nodes like
-this:
-draw((0,0)..controls (0,100) and (100,100)..(100,0));
-
-   However, it is usually more convenient to just use the `..'
-operator, which tells `Asymptote' to choose its own control points
-using the algorithms described in Donald Knuth's monograph, The
-MetaFontbook, Chapter 14.  The user can still customize the guide (or
-path) by specifying direction, tension, and curl values.
-
-   The higher the tension, the straighter the curve is, and the more it
-approximates a straight line.  One can change the spline tension from
-its default value of 1 to any real value greater than or equal to 0.75
-(cf. John D. Hobby, Discrete and Computational Geometry 1, 1986):
-draw((100,0)..tension 2 ..(100,100)..(0,100));
-draw((100,0)..tension 3 and 2 ..(100,100)..(0,100));
-draw((100,0)..tension atleast 2 ..(100,100)..(0,100));
-
-   In these examples there is a space between `2' and `..'.  This is
-needed as `2.' is interpreted as a numerical constant.
-
-   The curl parameter specifies the curvature at the endpoints of a path
-(0 means straight; the default value of 1 means approximately circular):
-draw((100,0){curl 0}..(100,100)..{curl 0}(0,100));
-
-   The `MetaPost ...' path connector, which requests, when possible, an
-inflection-free curve confined to a triangle defined by the endpoints
-and directions, is implemented in `Asymptote' as the convenient
-abbreviation `::' for `..tension atleast 1 ..' (the ellipsis `...' is
-used in `Asymptote' to indicate a variable number of arguments; *note
-Rest arguments::).  For example, compare
-
-draw((0,0){up}..(100,25){right}..(200,0){down});
-
-
-with
-
-draw((0,0){up}::(100,25){right}::(200,0){down});
-
-
-
-The `---' connector is an abbreviation for `..tension atleast
-infinity..' and the `&' connector concatenates two paths, after first
-stripping off the last node of the first path (which normally should
-coincide with the first node of the second path).
-
-
-File: asymptote.info,  Node: Programming,  Next: LaTeX usage,  Prev: Bezier curves,  Up: Top
-
-6 Programming
-*************
-
-Here is a short introductory example to the `Asymptote' programming
-language that highlights the similarity of its control structures with
-those of C, C++, and Java: 
-// This is a comment.
-
-// Declaration: Declare x to be a real variable;
-real x;
-
-// Assignment: Assign the real variable x the value 1.
-x=1.0;
-
-// Conditional: Test if x equals 1 or not.
-if(x == 1.0) {
-  write("x equals 1.0");
-} else {
-  write("x is not equal to 1.0");
-}
-
-// Loop: iterate 10 times
-for(int i=0; i < 10; ++i) {
-  write(i);
-}
-
-   `Asymptote' supports `while', `do', `break', and `continue'
-statements just as in C/C++. It also supports the Java-style shorthand
-for iterating over all elements of an array:
-
-// Iterate over an array
-int[] array={1,1,2,3,5};
-for(int k : array) {
-  write(k);
-}
- In addition, it supports many features beyond the ones found in those
-languages.
-
-* Menu:
-
-* Data types::                  void, bool, int, real, pair, triple, string
-* Paths and guides::
-* Pens::                        Colors, line types, line widths, font sizes
-* Transforms::                  Affine transforms
-* Frames and pictures::         Canvases for immediate and deferred drawing
-* Files::                       Reading and writing your data
-* Variable initializers::       Initialize your variables
-* Structures::                  Organize your data
-* Operators::                   Arithmetic and logical operators
-* Implicit scaling::            Avoiding those ugly *s
-* Functions::                   Traditional and high-order functions
-* Arrays::                      Dynamic vectors
-* Casts::                       Implicit and explicit casts
-* Import::                      Importing external `Asymptote' modules
-* Static::                      Where to allocate your variable?
-
-
-File: asymptote.info,  Node: Data types,  Next: Paths and guides,  Up: Programming
-
-6.1 Data types
-==============
-
-`Asymptote' supports the following data types (in addition to
-user-defined types):
-
-`void'
-     The void type is used only by functions that take or return no
-     arguments.
-
-`bool'
-     a boolean type that can only take on the values `true' or `false'.
-     For example: bool b=true;
-
-     defines a boolean variable `b' and initializes it to the value
-     `true'. If no initializer is given: bool b;
-
-     the value `false' is assumed.
-
-`bool3'
-     an extended boolean type that can take on the values `true',
-     `default', or `false'. A bool3 type can be cast to or from a bool.
-     The default initializer for bool3 is `default'.
-
-`int'
-     an integer type; if no initializer is given, the implicit value `0'
-     is assumed. The minimum allowed value of an integer is `intMin'
-     and the maximum value is `intMax'.
-
-`real'
-     a real number; this should be set to the highest-precision native
-     floating-point type on the architecture. The implicit initializer
-     for reals is `0.0'. Real numbers have precision `realEpsilon',
-     with `realDigits' significant digits.  The smallest positive real
-     number is `realMin' and the largest positive real number is
-     `realMax'.  The variable `inf' and function `bool isnan(real x)'
-     are useful when floating-point exceptions are masked with the
-     `-mask' command-line option (the default in interactive mode).
-
-`pair'
-     complex number, that is, an ordered pair of real components
-     `(x,y)'.  The real and imaginary parts of a pair `z' can read as
-     `z.x' and `z.y'. We say that `x' and `y' are virtual members of
-     the data element pair; they cannot be directly modified, however.
-     The implicit initializer for pairs is `(0.0,0.0)'.
-
-     There are a number of ways to take the complex conjugate of a pair:
-          pair z=(3,4);
-          z=(z.x,-z.y);
-          z=z.x-I*z.y;
-          z=conj(z);
-
-     Here `I' is the pair `(0,1)'.  A number of built-in functions are
-     defined for pairs:
-
-    `pair conj(pair z)'
-          returns the conjugate of `z';
-
-    `real length(pair z)'
-          returns the complex modulus `|z|' of its argument `z'.  For
-          example,
-               pair z=(3,4);
-               length(z);
-          returns the result 5. A synonym for `length(pair)' is
-          `abs(pair)';
-
-    `real angle(pair z, bool warn=true)'
-          returns the angle of `z' in radians in the interval
-          [-`pi',`pi'] or `0' if `warn' is `false' and `z=(0,0)'
-          (rather than producing an error);
-
-    `real degrees(pair z, bool warn=true)'
-          returns the angle of `z' in degrees in the interval [0,360)
-          or `0' if `warn' is `false' and `z=(0,0)' (rather than
-          producing an error);
-
-    `pair unit(pair z)'
-          returns a unit vector in the direction of the pair `z';
-
-    `pair expi(real angle)'
-          returns a unit vector in the direction `angle' measured in
-          radians;
-
-    `pair dir(real degrees)'
-          returns a unit vector in the direction `degrees' measured in
-          degrees;
-
-    `real xpart(pair z)'
-          returns `z.x';
-
-    `real ypart(pair z)'
-          returns `z.y';
-
-    `pair realmult(pair z, pair w)'
-          returns the element-by-element product `(z.x*w.x,z.y*w.y)';
-
-    `real dot(explicit pair z, explicit pair w)'
-          returns the dot product `z.x*w.x+z.y*w.y';
-
-    `pair minbound(pair z, pair w)'
-          returns `(min(z.x,w.x),min(z.y,w.y))';
-
-    `pair maxbound(pair z, pair w)'
-          returns `(max(z.x,w.x),max(z.y,w.y))'.
-
-
-`triple'
-     an ordered triple of real components `(x,y,z)' used for
-     three-dimensional drawings. The respective components of a triple
-     `v' can read as `v.x', `v.y', and `v.z'.  The implicit initializer
-     for triples is `(0.0,0.0,0.0)'.
-
-     Here are the built-in functions for triples:
-    `real length(triple v)'
-          returns the length `|v|' of the vector `v'.  A synonym for
-          `length(triple)' is `abs(triple)';
-
-    `real polar(triple v, bool warn=true)'
-          returns the colatitude of `v' measured from the z axis in
-          radians or `0' if `warn' is `false' and `v=O' (rather than
-          producing an error);
-
-    `real azimuth(triple v, bool warn=true)'
-          returns the longitude of `v' measured from the x axis in
-          radians or `0' if `warn' is `false' and `v.x=v.y=0' (rather
-          than producing an error);
-
-    `real colatitude(triple v, bool warn=true)'
-          returns the colatitude of `v' measured from the z axis in
-          degrees or `0' if `warn' is `false' and `v=O' (rather than
-          producing an error);
-
-    `real latitude(triple v, bool warn=true)'
-          returns the latitude of `v' measured from the xy plane in
-          degrees or `0' if `warn' is `false' and `v=O' (rather than
-          producing an error);
-
-    `real longitude(triple v, bool warn=true)'
-          returns the longitude of `v' measured from the x axis in
-          degrees or `0' if `warn' is `false' and `v.x=v.y=0' (rather
-          than producing an error);
-
-    `triple unit(triple v)'
-          returns a unit triple in the direction of the triple `v';
-
-    `triple expi(real polar, real azimuth)'
-          returns a unit triple in the direction `(polar,azimuth)'
-          measured in radians;
-
-    `triple dir(real colatitude, real longitude)'
-          returns a unit triple in the direction
-          `(colatitude,longitude)' measured in degrees;
-
-    `real xpart(triple v)'
-          returns `v.x';
-
-    `real ypart(triple v)'
-          returns `v.y';
-
-    `real zpart(triple v)'
-          returns `v.z';
-
-    `real dot(triple u, triple v)'
-          returns the dot product `u.x*v.x+u.y*v.y+u.z*v.z';
-
-    `triple cross(triple u, triple v)'
-          returns the cross product
-
-          `(u.y*v.z-u.z*v.y,u.z*v.x-u.x*v.z,u.x*v.y-v.x*u.y)';
-
-    `triple minbound(triple u, triple v)'
-          returns `(min(u.x,v.x),min(u.y,v.y),min(u.z,v.z))';
-
-    `triple maxbound(triple u, triple v)'
-          returns `(max(u.x,v.x),max(u.y,v.y),max(u.z,v.z)').
-
-
-`string'
-     a character string, implemented using the STL `string' class.
-
-     Strings delimited by double quotes (`"') are subject to the
-     following mappings to allow the use of double quotes in TeX (e.g.
-     for using the `babel' package, *note babel::):
-
-        * \" maps to "
-
-        * \\ maps to \\
-
-     Strings delimited by single quotes (`'') have the same mappings as
-     character strings in ANSI `C':
-
-        * \' maps to '
-
-        * \" maps to "
-
-        * \? maps to ?
-
-        * \\ maps to backslash
-
-        * \a maps to alert
-
-        * \b maps to backspace
-
-        * \f maps to form feed
-
-        * \n maps to newline
-
-        * \r maps to carriage return
-
-        * \t maps to tab
-
-        * \v maps to vertical tab
-
-        * \0-\377 map to corresponding octal byte
-
-        * \x0-\xFF map to corresponding hexadecimal byte
-
-     The implicit initializer for strings is the empty string `""'.
-     Strings may be concatenated with the `+' operator. In the following
-     string functions, position `0' denotes the start of the string:
-    `int length(string s)'
-          returns the length of the string `s';
-
-    `int find(string s, string t, int pos=0)'
-          returns the position of the first occurrence of string `t' in
-          string `s' at or after position `pos', or -1 if `t' is not a
-          substring of `s';
-
-    `int rfind(string s, string t, int pos=-1)'
-          returns the position of the last occurrence of string `t' in
-          string `s' at or before position `pos' (if `pos'=-1, at the
-          end of the string `s'), or -1 if `t' is not a substring of
-          `s';
-
-    `string insert(string s, int pos, string t)'
-          returns the string formed by inserting string `t' at position
-          `pos' in `s';
-
-    `string erase(string s, int pos, int n)'
-          returns the string formed by erasing the string of length `n'
-          (if `n'=-1, to the end of the string `s') at position `pos'
-          in `s';
-
-    `string substr(string s, int pos, int n=-1)'
-          returns the substring of `s' starting at position `pos' and
-          of length `n' (if `n'=-1, until the end of the string `s');
-
-    `string reverse(string s)'
-          returns the string formed by reversing string `s';
-
-    `string replace(string s, string before, string after)'
-          returns a string with all occurrences of the string `before'
-          in the string `s' changed to the string `after';
-
-    `string replace(string s, string[][] table)'
-          returns a string constructed by translating in string `s' all
-          occurrences of the string `before' in an array `table' of
-          string pairs {`before',`after'} to the corresponding string
-          `after';
-
-    `string[] split(string s, string delimiter="")'
-          returns an array of strings obtained by splitting `s' into
-          substrings delimited by `delimiter' (an empty delimiter
-          signifies a space, but with duplicate delimiters discarded);
-
-    `string format(string s, int n, string locale="")'
-          returns a string containing `n' formatted according to the
-          C-style format string `s' using locale `locale' (or the
-          current locale if an empty string is specified);
-
-    `string format(string s=defaultformat, string s=defaultseparator, real x, string locale="")'
-          returns a string containing `x' formatted according to the
-          C-style format string `s' using locale `locale' (or the
-          current locale if an empty string is specified), following
-          the behaviour of the C function `fprintf'), except that only
-          one data field is allowed, trailing zeros are removed by
-          default (unless `#' is specified), and (if the format string
-          specifies math mode) TeX is used to typeset scientific
-          notation using the `defaultseparator="\!\times\!";';
-
-    `int hex(string s);'
-          casts a hexidecimal string `s' to an integer;
-
-    `int ascii(string s);'
-          returns the ASCII code for the first character of string `s';
-
-    `string string(real x, int digits=realDigits)'
-          casts `x' to a string using precision `digits' and the C
-          locale;
-
-    `string locale(string s="")'
-          sets the locale to the given string, if nonempty, and returns
-          the current locale;
-
-    `string time(string format="%a %b %d %T %Z %Y")'
-          returns the current time formatted by the ANSI C routine
-          `strftime' according to the string `format' using the current
-          locale. Thus time();
-          time("%a %b %d %H:%M:%S %Z %Y");
-
-          are equivalent ways of returning the current time in the
-          default format used by the `UNIX' `date' command;
-
-    `int seconds(string t="", string format="")'
-          returns the time measured in seconds after the Epoch (Thu Jan
-          01 00:00:00 UTC 1970) as determined by the ANSI C routine
-          `strptime' according to the string `format' using the current
-          locale, or the current time if `t' is the empty string.  Note
-          that the `"%Z"' extension to the POSIX `strptime'
-          specification is ignored by the current GNU C Library. If an
-          error occurs, the value -1 is returned. Here are some
-          examples: seconds("Mar 02 11:12:36 AM PST 2007","%b %d %r PST %Y");
-          seconds(time("%b %d %r %z %Y"),"%b %d %r %z %Y");
-          seconds(time("%b %d %r %Z %Y"),"%b %d %r "+time("%Z")+" %Y");
-          1+(seconds()-seconds("Jan 1","%b %d"))/(24*60*60);
-           The last example returns today's ordinal date, measured from
-          the beginning of the year.
-
-    `string time(int seconds, string format="%a %b %d %T %Z %Y")'
-          returns the time corresponding to `seconds' seconds after the
-          Epoch (Thu Jan 01 00:00:00 UTC 1970) formatted by the ANSI C
-          routine `strftime' according to the string `format' using the
-          current locale. For example, to return the date corresponding
-          to 24 hours ago: time(seconds()-24*60*60);
-
-    `int system(string s)'
-
-    `int system(string[] s)'
-          if the setting `safe' is false, call the arbitrary system
-          command `s';
-
-    `void asy(string format, bool overwrite=false ... string[] s)'
-          conditionally process each file name in array `s' in a new
-          environment, using format `format', overwriting the output
-          file only if `overwrite' is true;
-
-    `void abort(string s="")'
-          aborts execution (with a non-zero return code in batch mode);
-          if string `s' is nonempty, a diagnostic message constructed
-          from the source file, line number, and `s' is printed;
-
-    `void assert(bool b, string s="")'
-          aborts execution with an error message constructed from `s' if
-          `b=false';
-
-    `void exit()'
-          exits (with a zero error return code in batch mode);
-
-    `void sleep(int seconds)'
-          pauses for the given number of seconds;
-
-    `void usleep(int microseconds)'
-          pauses for the given number of microseconds;
-
-    `void beep()'
-          produces a beep on the console;
-
-
-
-   As in C/C++, complicated types may be abbreviated with `typedef'
-(see the example in *note Functions::).
-
-
-File: asymptote.info,  Node: Paths and guides,  Next: Pens,  Prev: Data types,  Up: Programming
-
-6.2 Paths and guides
-====================
-
-`path'
-     a cubic spline resolved into a fixed path.  The implicit
-     initializer for paths is `nullpath'.
-
-     For example, the routine `circle(pair c, real r)', which returns a
-     Bezier curve approximating a circle of radius `r' centered on `c',
-     is based on `unitcircle' (*note unitcircle::): path circle(pair c, real r)
-     {
-       return shift(c)*scale(r)*unitcircle;
-     }
-      If high accuracy is needed, a true circle may be produced with the
-     routine `Circle' defined in the module `graph.asy': import graph;
-     path Circle(pair c, real r, int n=nCircle);
-
-     A circular arc consistent with `circle' centered on `c' with
-     radius `r' from `angle1' to `angle2' degrees, drawing
-     counterclockwise if `angle2 >= angle1', can be constructed with path arc(pair c, real r, real angle1, real angle2);
-      One may also specify the direction explicitly: path arc(pair c, real r, real angle1, real angle2, bool direction);
-      Here the direction can be specified as CCW (counter-clockwise) or
-     CW (clockwise). For convenience, an arc centered at `c' from pair
-     `z1' to `z2' (assuming `|z2-c|=|z1-c|') in the may also be
-     constructed with path arc(pair c, explicit pair z1, explicit pair z2,
-              bool direction=CCW)
-
-     If high accuracy is needed, true arcs may be produced with routines
-     in the module `graph.asy' that produce Bezier curves with `n'
-     control points: import graph;
-     path Arc(pair c, real r, real angle1, real angle2, bool direction,
-              int n=nCircle);
-     path Arc(pair c, real r, real angle1, real angle2, int n=nCircle);
-     path Arc(pair c, explicit pair z1, explicit pair z2,
-              bool direction=CCW, int n=nCircle);
-
-     An ellipse can be drawn with the routine path ellipse(pair c, real a, real b)
-     {
-       return shift(c)*scale(a,b)*unitcircle;
-     }
-
-     This example illustrates the use of all five guide connectors
-     discussed in *note Tutorial:: and *note Bezier curves::: size(300,0);
-     pair[] z=new pair[10];
-
-     z[0]=(0,100); z[1]=(50,0); z[2]=(180,0);
-
-     for(int n=3; n <= 9; ++n)
-       z[n]=z[n-3]+(200,0);
-
-     path p=z[0]..z[1]---z[2]::{up}z[3]
-     &z[3]..z[4]--z[5]::{up}z[6]
-     &z[6]::z[7]---z[8]..{up}z[9];
-
-     draw(p,grey+linewidth(4mm));
-
-     dot(z);
-
-
-
-     Here are some useful functions for paths:
-
-    `int length(path p);'
-          This is the number of (linear or cubic) segments in path `p'.
-          If `p' is cyclic, this is the same as the number of nodes in
-          `p'.
-
-    `int size(path p);'
-          This is the number of nodes in the path `p'.  If `p' is
-          cyclic, this is the same as `length(p)'.
-
-    `bool cyclic(path p);'
-          returns `true' iff path `p' is cyclic.
-
-    `bool straight(path p, int i);'
-          returns `true' iff the segment of path `p' between node `i'
-          and node `i+1' is straight.
-
-    `bool piecewisestraight(path p)'
-          returns `true' iff the path `p' is piecewise straight.
-
-    `pair point(path p, int t);'
-          If `p' is cyclic, return the coordinates of node `t' mod
-          `length(p)'. Otherwise, return the coordinates of node `t',
-          unless `t' < 0 (in which case `point(0)' is returned) or `t'
-          > `length(p)' (in which case `point(length(p))' is returned).
-
-    `pair point(path p, real t);'
-          This returns the coordinates of the point between node
-          `floor(t)' and `floor(t)+1' corresponding to the cubic spline
-          parameter `t-floor(t)' (*note Bezier curves::). If `t' lies
-          outside the range [0,`length(p)'], it is first reduced modulo
-          `length(p)' in the case where `p' is cyclic or else converted
-          to the corresponding endpoint of `p'.
-
-    `pair dir(path p, int t, int sign=0, bool normalize=true);'
-          If `sign < 0', return the direction (as a pair) of the
-          incoming tangent to path `p' at node `t'; if `sign > 0',
-          return the direction of the outgoing tangent. If `sign=0',
-          the mean of these two directions is returned.
-
-    `pair dir(path p, real t, bool normalize=true);'
-          returns the direction of the tangent to path `p' at the point
-          between node `floor(t)' and `floor(t)+1' corresponding to the
-          cubic spline parameter `t-floor(t)' (*note Bezier curves::).
-
-    `pair dir(path p)'
-          returns dir(p,length(p)).
-
-    `pair dir(path p, path q)'
-          returns unit(dir(p)+dir(q)).
-
-    `pair accel(path p, int t, int sign=0);'
-          If `sign < 0', return the acceleration of the incoming path
-          `p' at node `t'; if `sign > 0', return the acceleration of
-          the outgoing path. If `sign=0', the mean of these two
-          accelerations is returned.
-
-    `pair accel(path p, real t);'
-          returns the acceleration of the path `p' at the point `t'.
-
-    `real radius(path p, real t);'
-          returns the radius of curvature of the path `p' at the point
-          `t'.
-
-    `pair precontrol(path p, int t);'
-          returns the precontrol point of `p' at node `t'.
-
-    `pair precontrol(path p, real t);'
-          returns the effective precontrol point of `p' at parameter
-          `t'.
-
-    `pair postcontrol(path p, int t);'
-          returns the postcontrol point of `p' at node `t'.
-
-    `pair postcontrol(path p, real t);'
-          returns the effective postcontrol point  of `p' at parameter
-          `t'.
-
-    `real arclength(path p);'
-          returns the length (in user coordinates) of the piecewise
-          linear or cubic curve that path `p' represents.
-
-    `real arctime(path p, real L);'
-          returns the path "time", a real number between 0 and the
-          length of the path in the sense of `point(path p, real t)',
-          at which the cumulative arclength (measured from the
-          beginning of the path) equals `L'.
-
-    `real arcpoint(path p, real L);'
-          returns `point(p,arctime(p,L))'.
-
-    `real dirtime(path p, pair z);'
-          returns the first "time", a real number between 0 and the
-          length of the path in the sense of `point(path, real)', at
-          which the tangent to the path has the direction of pair `z',
-          or -1 if this never happens.
-
-    `real reltime(path p, real l);'
-          returns the time on path `p' at the relative fraction `l' of
-          its arclength.
-
-    `pair relpoint(path p, real l);'
-          returns the point on path `p' at the relative fraction `l' of
-          its arclength.
-
-    `pair midpoint(path p);'
-          returns the point on path `p' at half of its arclength.
-
-    `path reverse(path p);'
-          returns a path running backwards along `p'.
-
-    `path subpath(path p, int a, int b);'
-          returns the subpath of `p' running from node `a' to node `b'.
-          If `a' < `b', the direction of the subpath is reversed.
-
-    `path subpath(path p, real a, real b);'
-          returns the subpath  of `p' running from path time `a' to path
-          time `b', in the sense of `point(path, real)'. If `a' < `b',
-          the direction of the subpath is reversed.
-
-    `real[] intersect(path p, path q, real fuzz=-1);'
-          If `p' and `q' have at least one intersection point, return a
-          real array of length 2 containing the times representing the
-          respective path times along `p' and `q', in the sense of
-          `point(path, real)', for one such intersection point (as
-          chosen by the algorithm described on page 137 of `The
-          MetaFontbook').  The computations are performed to the
-          absolute error specified by `fuzz', or if `fuzz < 0', to
-          machine precision. If the paths do not intersect, return a
-          real array of length 0.
-
-    `real[][] intersections(path p, path q, real fuzz=-1);'
-          Return all (unless there are infinitely many) intersection
-          times of paths `p' and `q' as a sorted array of real arrays
-          of length 2 (*note sort::). The computations are performed to
-          the absolute error specified by `fuzz', or if `fuzz < 0', to
-          machine precision.
-
-    `real[] intersections(path p, explicit pair a, explicit pair b, real fuzz=-1);'
-          Return all (unless there are infinitely many) intersection
-          times of path `p' with the (infinite) line through points `a'
-          and `b' as a sorted array. The intersections returned are
-          guaranteed to be correct to within the absolute error
-          specified by `fuzz', or if `fuzz < 0', to machine precision.
-
-    `real[] times(path p, real x)'
-          returns all intersection times of path `p' with the vertical
-          line through `(x,0)'.
-
-    `real[] times(path p, explicit pair z)'
-          returns all intersection times of path `p' with the
-          horizontal line through `(0,z.y)'.
-
-    `real[] mintimes(path p)'
-          returns an array of length 2 containing times at which path
-          `p' reaches its minimal horizontal and vertical extents,
-          respectively.
-
-    `real[] maxtimes(path p)'
-          returns an array of length 2 containing times at which path
-          `p' reaches its maximal horizontal and vertical extents,
-          respectively.
-
-    `pair intersectionpoint(path p, path q, real fuzz=-1);'
-          returns the intersection point
-          `point(p,intersect(p,q,fuzz)[0])'.
-
-    `pair[] intersectionpoints(path p, path q, real fuzz=-1);'
-          returns an array containing all intersection points of the
-          paths `p' and `q'.
-
-    `pair extension(pair P, pair Q, pair p, pair q);'
-          returns the intersection point of the extensions of the line
-          segments `P--Q' and `p--q', or if the lines are parallel,
-          `(infinity,infinity)'.
-
-    `slice cut(path p, path knife, int n);'
-          returns the portions of path `p' before and after the `n'th
-          intersection of `p' with path `knife' as a structure `slice'
-          (if no intersection exist is found, the entire path is
-          considered to be `before' the intersection): struct slice {
-            path before,after;
-          }
-           The argument `n' is treated as modulo the number of
-          intersections.
-
-    `slice firstcut(path p, path knife);'
-          equivalent to `cut(p,knife,0);' Note that `firstcut.after'
-          plays the role of the `MetaPost cutbefore' command.
-
-    `slice lastcut(path p, path knife);'
-          equivalent to `cut(p,knife,-1);' Note that `lastcut.before'
-          plays the role of the `MetaPost cutafter' command.
-
-    `path buildcycle(... path[] p);'
-          This returns the path surrounding a region bounded by a list
-          of two or more consecutively intersecting paths, following
-          the behaviour of the `MetaPost buildcycle' command.
-
-    `pair min(path p);'
-          returns the pair (left,bottom) for the path bounding box of
-          path `p'.
-
-    `pair max(path p);'
-          returns the pair (right,top) for the path bounding box of
-          path `p'.
-
-    `int windingnumber(path p, pair z);'
-          returns the winding number of the cyclic path `p' relative to
-          the point `z'. The winding number is positive if the path
-          encircles `z' in the counterclockwise direction. If `z' lies
-          on `p' the constant `undefined' (defined to be the largest
-          odd integer) is returned.
-
-    `bool interior(int windingnumber, pen fillrule)'
-          returns true if `windingnumber' corresponds to an interior
-          point according to `fillrule'.
-
-    `bool inside(path p, pair z, pen fillrule=currentpen);'
-          returns `true' iff the point `z' lies inside or on the edge of
-          the region bounded by the cyclic path `p' according to the
-          fill rule `fillrule' (*note fillrule::).
-
-    `int inside(path p, path q, pen fillrule=currentpen);'
-          returns `1' if the cyclic path `p' strictly contains `q'
-          according to the fill rule `fillrule' (*note fillrule::), `-1'
-          if the cyclic path `q' strictly contains `p', and `0'
-          otherwise.
-
-    `pair inside(path p, pen fillrule=currentpen);'
-          returns an arbitrary point strictly inside a cyclic path `p'
-          according to the fill rule `fillrule' (*note fillrule::).
-
-    `path[] strokepath(path g, pen p=currentpen);'
-          returns the path array that `PostScript' would fill in
-          drawing path `g' with pen `p'.
-
-
-`guide'
-     an unresolved cubic spline (list of cubic-spline nodes and control
-     points).  The implicit initializer for a guide is `nullpath'; this
-     is useful for building up a guide within a loop.
-
-     A guide is similar to a path except that the computation of the
-     cubic spline is deferred until drawing time (when it is resolved
-     into a path); this allows two guides with free endpoint conditions
-     to be joined together smoothly.  The solid curve in the following
-     example is built up incrementally as a guide, but only resolved at
-     drawing time; the dashed curve is incrementally resolved at each
-     iteration, before the entire set of nodes (shown in red) is known:
-
-     size(200);
-
-     real mexican(real x) {return (1-8x^2)*exp(-(4x^2));}
-
-     int n=30;
-     real a=1.5;
-     real width=2a/n;
-
-     guide hat;
-     path solved;
-
-     for(int i=0; i < n; ++i) {
-       real t=-a+i*width;
-       pair z=(t,mexican(t));
-       hat=hat..z;
-       solved=solved..z;
-     }
-
-     draw(hat);
-     dot(hat,red);
-     draw(solved,dashed);
-
-
-
-     We point out an efficiency distinction in the use of guides and
-     paths: guide g;
-     for(int i=0; i < 10; ++i)
-       g=g--(i,i);
-     path p=g;
-
-     runs in linear time, whereas path p;
-     for(int i=0; i < 10; ++i)
-       p=p--(i,i);
-
-     runs in quadratic time, as the entire path up to that point is
-     copied at each step of the iteration.
-
-     The following routines can be used to examine the individual
-     elements of a guide without actually resolving the guide to a
-     fixed path (except for internal cycles, which are resolved):
-
-    `int size(guide g);'
-          Analogous to `size(path p)'.
-
-    `int length(guide g);'
-          Analogous to `length(path p)'.
-
-    `bool cyclic(path p);'
-          Analogous to `cyclic(path p)'.
-
-    `pair point(guide g, int t);'
-          Analogous to `point(path p, int t)'.
-
-    `guide reverse(guide g);'
-          Analogous to `reverse(path p)'. If `g' is cyclic and also
-          contains a secondary cycle, it is first solved to a path,
-          then reversed. If `g' is not cyclic but contains an internal
-          cycle, only the internal cycle is solved before reversal. If
-          there are no internal cycles, the guide is reversed but not
-          solved to a path.
-
-    `pair[] dirSpecifier(guide g, int i);'
-          This returns a pair array of length 2 containing the outgoing
-          (in element 0) and incoming (in element 1) direction
-          specifiers (or `(0,0)' if none specified) for the segment of
-          guide `g' between nodes `i' and `i+1'.
-
-    `pair[] controlSpecifier(guide g, int i);'
-          If the segment of guide `g' between nodes `i' and `i+1' has
-          explicit outgoing and incoming control points, they are
-          returned as elements 0 and 1, respectively, of a two-element
-          array. Otherwise, an empty array is returned.
-
-    `tensionSpecifier tensionSpecifier(guide g, int i);'
-          This returns the tension specifier for the segment of guide
-          `g' between nodes `i' and `i+1'. The individual components of
-          the `tensionSpecifier' type can be accessed as the virtual
-          members `in', `out', and `atLeast'.
-
-    `real[] curlSpecifier(guide g);'
-          This returns an array containing the initial curl specifier
-          (in element 0) and final curl specifier (in element 1) for
-          guide `g'.
-
-
-     As a technical detail we note that a direction specifier given to
-     `nullpath' modifies the node on the other side: the guides a..{up}nullpath..b;
-     c..nullpath{up}..d;
-     e..{up}nullpath{down}..f;
-      are respectively equivalent to a..nullpath..{up}b;
-     c{up}..nullpath..d;
-     e{down}..nullpath..{up}f;
-
-
-
-File: asymptote.info,  Node: Pens,  Next: Transforms,  Prev: Paths and guides,  Up: Programming
-
-6.3 Pens
-========
-
-In `Asymptote', pens provide a context for the four basic drawing
-commands (*note Drawing commands::). They are used to specify the
-following drawing attributes: color, line type, line width, line cap,
-line join, fill rule, text alignment, font, font size, pattern,
-overwrite mode, and calligraphic transforms on the pen nib. The default
-pen used by the drawing routines is called `currentpen'. This provides
-the same functionality as the `MetaPost' command `pickup'.  The
-implicit initializer for pens is `defaultpen'.
-
-   Pens may be added together with the nonassociative binary operator
-`+'. This will add the colors of the two pens.  All other non-default
-attributes of the rightmost pen will override those of the leftmost
-pen. Thus, one can obtain a yellow dashed pen by saying
-`dashed+red+green' or `red+green+dashed' or `red+dashed+green'. The
-binary operator `*' can be used to scale the color of a pen by a real
-number, until it saturates with one or more color components equal to 1.
-
-   * Colors are specified using one of the following colorspaces: 
-    `pen gray(real g);'
-          This produces a grayscale color, where the intensity `g' lies
-          in the interval [0,1], with 0.0 denoting black and 1.0
-          denoting white.
-
-    `pen rgb(real r, real g, real b);'
-          This produces an RGB color, where each of the red, green, and
-          blue intensities `r', `g', `b', lies in the interval [0,1].
-
-    `pen cmyk(real c, real m, real y, real k);'
-          This produces a CMYK color, where each of the cyan, magenta,
-          yellow, and black intensities `c', `m', `y', `k', lies in the
-          interval [0,1].
-
-    `pen invisible;'
-          This special pen writes in invisible ink, but adjusts the
-          bounding box as if something had been drawn (like the
-          `\phantom' command in TeX). The function `bool
-          invisible(pen)' can be used to test whether a pen is
-          invisible.
-
-
-     The default color is `black'; this may be changed with the routine
-     `defaultpen(pen)'. The function `colorspace(pen p)' returns the
-     colorspace of pen `p' as a string (`"gray"', `"rgb"', `"cmyk"', or
-     `""').
-
-     The function `real[] colors(pen)' returns the color components of
-     a pen.  The functions `pen gray(pen)', `pen rgb(pen)',  and `pen
-     cmyk(pen)' return new pens obtained by converting their arguments
-     to the respective color spaces.  The function
-     `colorless(pen=currentpen)' returns a copy of its argument with
-     the color attributes stripped (to avoid color mixing).
-
-     A 6-character RGB hexidecimal string can be converted to a pen with
-     the routine pen rgb(string s);
-      A pen can be converted to a hexidecimal string with 
-
-   * string hex(pen p);
-
-     Various shades and mixtures of the grayscale primary colors
-     `black' and `white', RGB primary colors `red', `green', and
-     `blue', and RGB secondary colors `cyan', `magenta', and `yellow'
-     are defined as named colors, along with the CMYK primary colors
-     `Cyan', `Magenta', `Yellow', and `Black', in the module `plain':
-
-
-
-     The standard 140 RGB `X11' colors can be imported with the command import x11colors;
-      and the standard 68 CMYK TeX colors can be imported with the
-     command import texcolors;
-      Note that there is some overlap between these two standards and
-     the definitions of some colors (e.g. `Green') actually disagree.
-
-     `Asymptote' also comes with a `asycolors.sty' `LaTeX' package that
-     defines to `LaTeX' CMYK versions of `Asymptote''s predefined
-     colors, so that they can be used directly within `LaTeX' strings.
-     Normally, such colors are passed to `LaTeX' via a pen argument;
-     however, to change the color of only a portion of a string, say
-     for a slide presentation, (*note slide::) it may be desirable to
-     specify the color directly to `LaTeX'. This file can be passed to
-     `LaTeX' with the `Asymptote' command usepackage("asycolors");
-
-     The structure `hsv' defined in `plain_pens.asy' may be used to
-     convert between HSV and RGB spaces, where the hue `h' is an angle
-     in [0,360) and the saturation `s' and value `v' lie in `[0,1]': pen p=hsv(180,0.5,0.75);
-     write(p);           // ([default], red=0.375, green=0.75, blue=0.75)
-     hsv q=p;
-     write(q.h,q.s,q.v); // 180     0.5     0.75
-
-   * Line types are specified with the function `pen linetype(real[] a,
-     real offset=0, bool scale=true, bool adjust=true)', where `a' is
-     an array of real array numbers.  The optional parameter `offset'
-     specifies where in the pattern to begin. The first number
-     specifies how far (if `scale' is `true', in units of the pen line
-     width; otherwise in `PostScript' units) to draw with the pen on,
-     the second number specifies how far to draw with the pen off, and
-     so on. If `adjust' is `true', these spacings are automatically
-     adjusted by `Asymptote' to fit the arclength of the path. Here are
-     the predefined line types: pen solid=linetype(new real[]);
-     pen dotted=linetype(new real[] {0,4});
-     pen dashed=linetype(new real[] {8,8});
-     pen longdashed=linetype(new real[] {24,8});
-     pen dashdotted=linetype(new real[] {8,8,0,8});
-     pen longdashdotted=linetype(new real[] {24,8,0,8});
-     pen Dotted(pen p=currentpen) {return linetype(new real[] {0,3})+2*linewidth(p);}
-     pen Dotted=Dotted();
-
-
-
-     The default line type is `solid'; this may be changed with
-     `defaultpen(pen)'.  The line type of a pen can be determined with
-     the functions `real[] linetype(pen p=currentpen)', `real
-     offset(pen p)', `bool scale(pen p)', and `bool adjust(pen p)'.
-
-   * The pen line width is specified in `PostScript' units with `pen
-     linewidth(real)'. The default line width is 0.5 bp; this value may
-     be changed with `defaultpen(pen)'. The line width of a pen is
-     returned by `real linewidth(pen p=currentpen)'.  For convenience,
-     in the module `plain_pens' we define void defaultpen(real w) {defaultpen(linewidth(w));}
-     pen operator +(pen p, real w) {return p+linewidth(w);}
-     pen operator +(real w, pen p) {return linewidth(w)+p;}
-      so that one may set the line width like this: defaultpen(2);
-     pen p=red+0.5;
-
-   * A pen with a specific `PostScript' line cap is returned on calling
-     `linecap' with an integer argument: pen squarecap=linecap(0);
-     pen roundcap=linecap(1);
-     pen extendcap=linecap(2);
-
-     The default line cap, `roundcap', may be changed with
-     `defaultpen(pen)'. The line cap of a pen is returned by `int
-     linecap(pen p=currentpen)'.
-
-   * A pen with a specific `PostScript' join style is returned on
-     calling `linejoin' with an integer argument: pen miterjoin=linejoin(0);
-     pen roundjoin=linejoin(1);
-     pen beveljoin=linejoin(2);
-
-     The default join style, `roundjoin', may be changed with
-     `defaultpen(pen)'.The join style of a pen is returned by `int
-     linejoin(pen p=currentpen)'.
-
-   * A pen with a specific `PostScript' miter limit is returned by
-     calling `miterlimit(real)'.  The default miterlimit, `10.0', may
-     be changed with `defaultpen(pen)'. The miter limit of a pen is
-     returned by `real miterlimit(pen p=currentpen)'.
-
-   * A pen with a specific `PostScript' fill rule is returned on
-     calling `fillrule' with an integer argument: pen zerowinding=fillrule(0);
-     pen evenodd=fillrule(1);
-
-     The fill rule, which identifies the algorithm used to determine the
-     insideness of a path or array of paths, only affects the `clip',
-     `fill', and `inside' functions. For the `zerowinding' fill rule, a
-     point `z' is outside the region bounded by a path if the number of
-     upward intersections of the path with the horizontal line
-     `z--z+infinity' minus the number of downward intersections is
-     zero. For the `evenodd' fill rule, `z' is considered to be outside
-     the region if the total number of such intersections is even.  The
-     default fill rule, `zerowinding', may be changed with
-     `defaultpen(pen)'. The fill rule of a pen is returned by `int
-     fillrule(pen p=currentpen)'.
-
-   * A pen with a specific text alignment setting is returned on
-     calling `basealign' with an integer argument: pen nobasealign=basealign(0);
-     pen basealign=basealign(1);
-
-     The default setting, `nobasealign',which may be changed with
-     `defaultpen(pen)', causes the label alignment routines to use the
-     full label bounding box for alignment. In contrast, `basealign'
-     requests that the TeX baseline be respected.  The base align
-     setting of a pen is returned by `int basealigin(pen p=currentpen)'.
-
-   * The font size is specified in TeX points (1 pt = 1/72.27 inches)
-     with the function `pen fontsize(real size, real
-     lineskip=1.2*size)'.  The default font size, 12pt, may be changed
-     with `defaultpen(pen)'.  Nonstandard font sizes may require
-     inserting import fontsize;
-      at the beginning of the file (this requires the `type1cm' package
-     available from
-
-          `http://www.ctan.org/tex-archive/macros/latex/contrib/type1cm/'
-     and included in recent `LaTeX' distributions). The font size and
-     line skip of a pen can be examined with the routines `real
-     fontsize(pen p=currentpen)' and `real lineskip(pen p=currentpen)',
-     respectively.
-
-   * A pen using a specific `LaTeX' `NFSS' font is returned by calling
-     the function `pen font(string encoding, string family, string
-     series, string shape)'. The default setting,
-     `font("OT1","cmr","m","n")', corresponds to 12pt Computer Modern
-     Roman; this may be changed with `defaultpen(pen)'.  The font
-     setting of a pen is returned by `string font(pen p=currentpen)'.
-     Support for standardized international characters is provided by
-     the `unicode' package (*note unicode::).
-
-     Alternatively, one may select a fixed-size TeX font (on which
-     `fontsize' has no effect) like `"cmr12"' (12pt Computer Modern
-     Roman) or `"pcrr"' (Courier) using the function `pen font(string
-     name)'. An optional size argument can also be given to scale the
-     font to the requested size: `pen font(string name, real size)'.
-
-     A nonstandard font command can be generated with `pen
-     fontcommand(string)'.
-
-     A convenient interface to the following standard `PostScript'
-     fonts is also provided: pen AvantGarde(string series="m", string shape="n");
-     pen Bookman(string series="m", string shape="n");
-     pen Courier(string series="m", string shape="n");
-     pen Helvetica(string series="m", string shape="n");
-     pen NewCenturySchoolBook(string series="m", string shape="n");
-     pen Palatino(string series="m", string shape="n");
-     pen TimesRoman(string series="m", string shape="n");
-     pen ZapfChancery(string series="m", string shape="n");
-     pen Symbol(string series="m", string shape="n");
-     pen ZapfDingbats(string series="m", string shape="n");
-
-   * The transparency of a pen can be changed with the command: pen opacity(real opacity=1, string blend="Compatible");
-      The opacity can be varied from `0' (fully transparent) to the
-     default value of `1' (opaque), and `blend' specifies one of the
-     following foreground-background blending operations: "Compatible","Normal","Multiply","Screen","Overlay","SoftLight",
-     "HardLight","ColorDodge","ColorBurn","Darken","Lighten","Difference",
-     "Exclusion","Hue","Saturation","Color","Luminosity",
-      as described in
-
-     `http://partners.adobe.com/public/developer/en/pdf/PDFReference16.pdf'.
-     Since `PostScript' does not support transparency, this feature is
-     only effective with the `-f pdf' output format option; other
-     formats can be produced from the resulting PDF file with the
-     `ImageMagick' `convert' program.  Labels are always drawn with an
-     `opacity' of 1.  A simple example of transparent filling is
-     provided in the example file `transparency.asy'.
-
-   * `PostScript' commands within a `picture' may be used to create a
-     tiling pattern, identified by the string `name', for `fill' and
-     `draw' operations by adding it to the global `PostScript' frame
-     `currentpatterns', with optional left-bottom margin `lb' and
-     right-top margin `rt'.  import patterns;
-     void add(string name, picture pic, pair lb=0, pair rt=0);
-
-     To `fill' or `draw' using pattern `name', use the pen
-     `pattern("name")'. For example, rectangular tilings can be
-     constructed using the routines `picture tile(real Hx=5mm, real
-     Hy=0, pen p=currentpen, filltype filltype=NoFill)', `picture
-     checker(real Hx=5mm, real Hy=0, pen p=currentpen)', and `picture
-     brick(real Hx=5mm, real Hy=0, pen p=currentpen)' defined in
-     `patterns.asy': size(0,90);
-     import patterns;
-
-     add("tile",tile());
-     add("filledtilewithmargin",tile(6mm,4mm,red,Fill),(1mm,1mm),(1mm,1mm));
-     add("checker",checker());
-     add("brick",brick());
-
-     real s=2.5;
-     filldraw(unitcircle,pattern("tile"));
-     filldraw(shift(s,0)*unitcircle,pattern("filledtilewithmargin"));
-     filldraw(shift(2s,0)*unitcircle,pattern("checker"));
-     filldraw(shift(3s,0)*unitcircle,pattern("brick"));
-
-
-
-     Hatch patterns can be generated with the routines `picture
-     hatch(real H=5mm, pair dir=NE, pen p=currentpen)', `picture
-     crosshatch(real H=5mm, pen p=currentpen)': size(0,100);
-     import patterns;
-
-     add("hatch",hatch());
-     add("hatchback",hatch(NW));
-     add("crosshatch",crosshatch(3mm));
-
-     real s=1.25;
-     filldraw(unitsquare,pattern("hatch"));
-     filldraw(shift(s,0)*unitsquare,pattern("hatchback"));
-     filldraw(shift(2s,0)*unitsquare,pattern("crosshatch"));
-
-
-
-     You may need to turn off aliasing in your `PostScript' viewer for
-     patterns to appear correctly. Custom patterns can easily be
-     constructed, following the examples in `patterns.asy'. The tiled
-     pattern can even incorporate shading (*note gradient shading::),
-     as illustrated in this example (not included in the manual because
-     not all printers support `PostScript' 3): size(0,100);
-     import patterns;
-
-     real d=4mm;
-     picture tiling;
-     path square=scale(d)*unitsquare;
-     axialshade(tiling,square,white,(0,0),black,(d,d));
-     fill(tiling,shift(d,d)*square,blue);
-     add("shadedtiling",tiling);
-
-     filldraw(unitcircle,pattern("shadedtiling"));
-
-      
-
-   * One can specify a custom pen nib as an arbitrary polygonal path
-     with `pen makepen(path)'; this path represents the mark to be
-     drawn for paths containing a single point. This pen nib path can be
-     recovered from a pen with `path nib(pen)'. Unlike in `MetaPost',
-     the path need not be convex:
-
-     size(200);
-     pen convex=makepen(scale(10)*polygon(8))+grey;
-     draw((1,0.4),convex);
-     draw((0,0)---(1,1)..(2,0)--cycle,convex);
-
-     pen nonconvex=scale(10)*
-       makepen((0,0)--(0.25,-1)--(0.5,0.25)--(1,0)--(0.5,1.25)--cycle)+red;
-     draw((0.5,-1.5),nonconvex);
-     draw((0,-1.5)..(1,-0.5)..(2,-1.5),nonconvex);
-
-
-
-     The value `nullpath' represents a circular pen nib (the default);
-     an elliptical pen can be achieved simply by multiplying the pen by
-     a transform: `yscale(2)*currentpen'.
-
-   * One can prevent labels from overwriting one another by using the
-     pen attribute `overwrite', which takes a single argument:
-
-    `Allow'
-          Allow labels to overwrite one another. This is the default
-          behaviour (unless overridden with `defaultpen(pen)'.
-
-    `Suppress'
-          Suppress, with a warning, each label that would overwrite
-          another label.
-
-    `SuppressQuiet'
-          Suppress, without warning, each label that would overwrite
-          another label.
-
-    `Move'
-          Move a label that would overwrite another out of the way and
-          issue a warning.  As this adjustment is during the final
-          output phase (in `PostScript' coordinates) it could result in
-          a larger figure than requested.
-
-    `MoveQuiet'
-          Move a label that would overwrite another out of the way,
-          without warning.  As this adjustment is during the final
-          output phase (in `PostScript' coordinates) it could result in
-          a larger figure than requested.
-
-
-
-   The routine `defaultpen()' returns the current default pen
-attributes.  Calling the routine `resetdefaultpen()' resets all pen
-default attributes to their initial values.
-
-
-File: asymptote.info,  Node: Transforms,  Next: Frames and pictures,  Prev: Pens,  Up: Programming
-
-6.4 Transforms
-==============
-
-`Asymptote' makes extensive use of affine transforms. A pair `(x,y)' is
-transformed by the transform `t=(t.x,t.y,t.xx,t.xy,t.yx,t.yy)' to
-`(x',y')', where
-x' = t.x + t.xx * x + t.xy * y
-y' = t.y + t.yx * x + t.yy * y
- This is equivalent to the `PostScript' transformation `[t.xx t.yx t.xy
-t.yy t.x t.y]'.
-
-   Transforms can be applied to pairs, guides, paths, pens, strings,
-transforms, frames, and pictures by multiplication (via the binary
-operator `*') on the left (*note circle:: for an example).  Transforms
-can be composed with one another and inverted with the function
-`transform inverse(transform t)'; they can also be raised to any
-integer power with the `^' operator.
-
-   The built-in transforms are:
-
-`transform identity();'
-     the identity transform;
-
-`transform shift(pair z);'
-     translates by the pair `z';
-
-`transform shift(real x, real y);'
-     translates by the pair `(x,y)';
-
-`transform xscale(real x);'
-     scales by `x' in the x direction;
-
-`transform yscale(real y);'
-     scales by `y' in the y direction;
-
-`transform scale(real s);'
-     scale by `s' in both x and y directions;
-
-`transform scale(real x, real y);'
-     scale by `x' in the x direction and by `y' in the y direction;
-
-`transform slant(real s);'
-     maps `(x,y)' -> `(x+s*y,y)';
-
-`transform rotate(real angle, pair z=(0,0));'
-     rotates by `angle' in degrees about `z';
-
-`transform reflect(pair a, pair b);'
-     reflects about the line `a--b'.
-
-   The implicit initializer for transforms is `identity()'.  The
-routines `shift(transform t)' and `shiftless(transform t)' return the
-transforms `(t.x,t.y,0,0,0,0)' and `(0,0,t.xx,t.xy,t.yx,t.yy)'
-respectively.
-
-
-File: asymptote.info,  Node: Frames and pictures,  Next: Files,  Prev: Transforms,  Up: Programming
-
-6.5 Frames and pictures
-=======================
-
-`frame'
-     Frames are canvases for drawing in `PostScript' coordinates. While
-     working with frames directly is occasionally necessary for
-     constructing deferred drawing routines, pictures are usually more
-     convenient to work with.  The implicit initializer for frames is
-     `newframe'. The function `bool empty(frame f)' returns `true' only
-     if the frame `f' is empty. A frame may be erased with the
-     `erase(frame)' routine.  The functions `pair min(frame)' and `pair
-     max(frame)' return the (left,bottom) and (right,top) coordinates
-     of the frame bounding box, respectively. The contents of frame
-     `src' may be appended to frame `dest' with the command void add(frame dest, frame src);
-      or prepended with void prepend(frame dest, frame src);
-      A frame obtained by aligning frame `f' in the direction `align',
-     in a manner analogous to the `align' argument of `label' (*note
-     label::), is returned by frame align(frame f, pair align);
-
-     To draw or fill a box or ellipse around a label or frame and
-     return the boundary as a path, use one of the predefined
-     `envelope' routines path box(frame f, Label L="", real xmargin=0,
-              real ymargin=xmargin, pen p=currentpen,
-              filltype filltype=NoFill, bool above=true);
-     path roundbox(frame f, Label L="", real xmargin=0,
-                   real ymargin=xmargin, pen p=currentpen,
-                   filltype filltype=NoFill, bool above=true);
-     path ellipse(frame f, Label L="", real xmargin=0,
-                  real ymargin=xmargin, pen p=currentpen,
-                  filltype filltype=NoFill, bool above=true);
-
-`picture'
-     Pictures are high-level structures (*note Structures::) defined in
-     the module `plain' that provide canvases for drawing in user
-     coordinates.  The default picture is called `currentpicture'. A
-     new picture can be created like this: picture pic;
-      Anonymous pictures can be made by the expression `new picture'.
-
-     The `size' routine specifies the dimensions of the desired picture:
-
-     void size(picture pic=currentpicture, real x, real y=x,
-               bool keepAspect=Aspect);
-
-     If the `x' and `y' sizes are both 0, user coordinates will be
-     interpreted as `PostScript' coordinates. In this case, the
-     transform mapping `pic' to the final output frame is `identity()'.
-
-     If exactly one of `x' or `y' is 0, no size restriction is imposed
-     in that direction; it will be scaled the same as the other
-     direction.
-
-     If `keepAspect' is set to `Aspect' or `true', the picture will be
-     scaled with its aspect ratio preserved such that the final width
-     is no more than `x' and the final height is no more than `y'.
-
-     If `keepAspect' is set to `IgnoreAspect' or `false', the picture
-     will be scaled in both directions so that the final width is `x'
-     and the height is `y'.
-
-     To make the user coordinates of picture `pic' represent multiples
-     of `x' units in the x direction and `y' units in the y direction,
-     use void unitsize(picture pic=currentpicture, real x, real y=x);
-      When nonzero, these `x' and `y' values override the corresponding
-     size parameters of picture `pic'.
-
-     The routine void size(picture pic=currentpicture, real xsize, real ysize,
-               pair min, pair max);
-      forces the final picture scaling to map the user coordinates
-     `box(min,max)' to a region of width `xsize' and height `ysize'
-     (when these parameters are nonzero).
-
-     Alternatively, calling the routine transform fixedscaling(picture pic=currentpicture, pair min,
-                            pair max, pen p=nullpen, bool warn=false);
-      will cause picture `pic' to use a fixed scaling to map user
-     coordinates in `box(min,max)' to the (already specified) picture
-     size, taking account of the width of pen `p'. A warning will be
-     issued if the final picture exceeds the specified size.
-
-     A picture `pic' can be fit to a frame and output to a file
-     `prefix'.`format' using image format `format' by calling the
-     `shipout' function: void shipout(string prefix=defaultfilename, picture pic=currentpicture,
-                  orientation orientation=orientation,
-                  string format="", bool wait=false, bool view=true,
-                  string options="", string script="",
-                  light light=currentlight, projection P=currentprojection)
-      The default output format, `PostScript', may be changed with the
-     `-f' or `-tex' command-line options.  The `options', `script', and
-     `projection' parameters are only relevant for 3D pictures. If
-     `defaultfilename' is an empty string, the prefix `outprefix()'
-     will be used.
-
-     A `shipout()' command is added implicitly at file exit if no
-     previous `shipout' commands have been executed.  The default page
-     orientation is `Portrait'; this may be modified by changing the
-     variable `orientation'. To output in landscape mode, simply set
-     the variable `orientation=Landscape' or issue the command shipout(Landscape);
-
-     To rotate the page by -90 degrees, use the orientation `Seascape'.  The
-     orientation `UpsideDown' rotates the page by 180 degrees.
-
-     A picture `pic' can be explicitly fit to a frame by calling frame pic.fit(real xsize=pic.xsize, real ysize=pic.ysize,
-                   bool keepAspect=pic.keepAspect);
-      The default size and aspect ratio settings are those given to the
-     `size' command (which default to `0', `0', and `true',
-     respectively).  The transformation that would currently be used to
-     fit a picture `pic' to a frame is returned by the member function
-     `pic.calculateTransform()'.
-
-     In certain cases (e.g. 2D graphs) where only an approximate size
-     estimate for `pic' is available, the picture fitting routine frame pic.scale(real xsize=this.xsize, real ysize=this.ysize,
-                     bool keepAspect=this.keepAspect);
-      (which scales the resulting frame, including labels and fixed-size
-     objects) will enforce perfect compliance with the requested size
-     specification, but should not normally be required.
-
-     To draw a bounding box with margins around a picture, fit the
-     picture to a frame using the function frame bbox(picture pic=currentpicture, real xmargin=0,
-                real ymargin=xmargin, pen p=currentpen,
-                filltype filltype=NoFill);
-      Here `filltype' specifies one of the following fill types:
-    `FillDraw'
-          Fill the interior and draw the boundary.
-
-    `FillDraw(real xmargin=0, real ymargin=xmargin, pen fillpen=nullpen,'
-          `pen drawpen=nullpen)' If `fillpen' is `nullpen', fill with
-          the drawing pen; otherwise fill with pen `fillpen'.  If
-          `drawpen' is `nullpen', draw the boundary with `fillpen';
-          otherwise with `drawpen'. An optional margin of `xmargin' and
-          `ymargin' can be specified.
-
-    `Fill'
-          Fill the interior.
-
-    `Fill(real xmargin=0, real ymargin=xmargin, pen p=nullpen)'
-          If `p' is `nullpen', fill with the drawing pen; otherwise
-          fill with pen `p'. An optional margin of `xmargin' and
-          `ymargin' can be specified.
-
-    `NoFill'
-          Do not fill.
-
-    `Draw'
-          Draw only the boundary.
-
-    `Draw(real xmargin=0, real ymargin=xmargin, pen p=nullpen)'
-          If `p' is `nullpen', draw the boundary with the drawing pen;
-          otherwise draw with pen `p'. An optional margin of `xmargin'
-          and `ymargin' can be specified.
-
-    `UnFill'
-          Clip the region.
-
-    `UnFill(real xmargin=0, real ymargin=xmargin)'
-          Clip the region and surrounding margins `xmargin' and
-          `ymargin'.
-
-    `RadialShade(pen penc, pen penr)'
-          Fill varying radially from `penc' at the center of the
-          bounding box to `penr' at the edge.
-
-    `RadialShadeDraw(real xmargin=0, real ymargin=xmargin, pen penc,'
-          `pen penr, pen drawpen=nullpen)' Fill with RadialShade and
-          draw the boundary.
-
-
-     For example, to draw a bounding box around a picture with a 0.25 cm
-     margin and output the resulting frame, use the command: shipout(bbox(0.25cm));
-      A `picture' may be fit to a frame with the background color pen
-     `p', using the function `bbox(p,Fill)'.
-
-     The functions pair min(picture pic, user=false);
-     pair max(picture pic, user=false);
-     pair size(picture pic, user=false);
-      calculate the bounds that picture `pic' would have if it were
-     currently fit to a frame using its default size specification.  If
-     `user' is `false' the returned value is in `PostScript'
-     coordinates, otherwise it is in user coordinates.
-
-     The function pair point(picture pic=currentpicture, pair dir, bool user=true);
-      is a convenient way of determining the point on the bounding box
-     of `pic' in the direction `dir' relative to its center, ignoring
-     the contributions from fixed-size objects (such as labels and
-     arrowheads).  If `user' is `true' the returned value is in user
-     coordinates, otherwise it is in `PostScript' coordinates.
-
-     The function pair truepoint(picture pic=currentpicture, pair dir, bool user=true);
-      is identical to `point', except that it also accounts for
-     fixed-size objects, using the scaling transform that picture `pic'
-     would have if currently fit to a frame using its default size
-     specification. If `user' is `true' the returned value is in user
-     coordinates, otherwise it is in `PostScript' coordinates.
-
-     Sometimes it is useful to draw objects on separate pictures and
-     add one picture to another using the `add' function: void add(picture src, bool group=true,
-              filltype filltype=NoFill, bool above=true);
-     void add(picture dest, picture src, bool group=true,
-              filltype filltype=NoFill, bool above=true);
-      The first example adds `src' to `currentpicture'; the second one
-     adds `src' to `dest'.  The `group' option specifies whether or not
-     the graphical user interface `xasy' should treat all of the
-     elements of `src' as a single entity (*note GUI::), `filltype'
-     requests optional background filling or clipping, and `above'
-     specifies whether to add `src' above or below existing objects.
-
-     There are also routines to add a picture or frame `src' specified
-     in postscript coordinates to another picture `dest' (or
-     `currentpicture') about the user coordinate `position': void add(picture src, pair position, bool group=true,
-              filltype filltype=NoFill, bool above=true);
-     void add(picture dest, picture src, pair position,
-              bool group=true, filltype filltype=NoFill, bool above=true);
-     void add(picture dest=currentpicture, frame src, pair position=0,
-              bool group=true, filltype filltype=NoFill, bool above=true);
-     void add(picture dest=currentpicture, frame src, pair position,
-              pair align, bool group=true, filltype filltype=NoFill,
-              bool above=true);
-
-     The optional `align' argument in the last form specifies a
-     direction to use for aligning the frame, in a manner analogous to
-     the `align' argument of `label' (*note label::). However, one key
-     difference is that when `align' is not specified, labels are
-     centered, whereas frames and pictures are aligned so that their
-     origin is at `position'. Illustrations of frame alignment can be
-     found in the examples *note errorbars:: and *note image::. If you
-     want to align three or more subpictures, group them two at a time:
-
-     picture pic1;
-     real size=50;
-     size(pic1,size);
-     fill(pic1,(0,0)--(50,100)--(100,0)--cycle,red);
-
-     picture pic2;
-     size(pic2,size);
-     fill(pic2,unitcircle,green);
-
-     picture pic3;
-     size(pic3,size);
-     fill(pic3,unitsquare,blue);
-
-     picture pic;
-     add(pic,pic1.fit(),(0,0),N);
-     add(pic,pic2.fit(),(0,0),10S);
-
-     add(pic.fit(),(0,0),N);
-     add(pic3.fit(),(0,0),10S);
-
-
-
-     Alternatively, one can use `attach' to automatically increase the
-     size of picture `dest' to accommodate adding a frame `src' about
-     the user coordinate `position': void attach(picture dest=currentpicture, frame src,
-                      pair position=0, bool group=true,
-                      filltype filltype=NoFill, bool above=true);
-     void attach(picture dest=currentpicture, frame src,
-                      pair position, pair align, bool group=true,
-                      filltype filltype=NoFill, bool above=true);
-
-     To erase the contents of a picture (but not the size
-     specification), use the function void erase(picture pic=currentpicture);
-
-     To save a snapshot of `currentpicture', `currentpen', and
-     `currentprojection', use the function `save()'.
-
-     To restore a snapshot of `currentpicture', `currentpen', and
-     `currentprojection', use the function `restore()'.
-
-     Many further examples of picture and frame operations are provided
-     in the base module `plain'.
-
-     It is possible to insert verbatim `PostScript' commands in a
-     picture with one of the routines void postscript(picture pic=currentpicture, string s);
-     void postscript(picture pic=currentpicture, string s, pair min,
-                     pair max)
-      Here `min' and `max' can be used to specify explicit bounds
-     associated with the resulting `PostScript' code.
-
-     Verbatim TeX commands can be inserted in the intermediate `LaTeX'
-     output file with one of the functions void tex(picture pic=currentpicture, string s);
-     void tex(picture pic=currentpicture, string s, pair min, pair max)
-      Here `min' and `max' can be used to specify explicit bounds
-     associated with the resulting TeX code.
-
-     To issue a global TeX command (such as a TeX macro definition) in
-     the TeX preamble (valid for the remainder of the top-level module)
-     use: void texpreamble(string s);
-
-     The TeX environment can be reset to its initial state, clearing all
-     macro definitions, with the function void texreset();
-
-     The routine void usepackage(string s, string options="");
-      provides a convenient abbreviation for texpreamble("\usepackage["+options+"]{"+s+"}");
-      that can be used for importing `LaTeX' packages.
-
-
-
-File: asymptote.info,  Node: Files,  Next: Variable initializers,  Prev: Frames and pictures,  Up: Programming
-
-6.6 Files
-=========
-
-`Asymptote' can read and write text files (including comma-separated
-value) files and portable XDR (External Data Representation) binary
-files.
-
-   An input file must first be opened with
-input(string name="", bool check=true, string comment="#", string mode="");
- reading is then done by assignment: 
-file fin=input("test.txt");
-real a=fin;
-
-   If the optional boolean argument `check' is `false', no check will
-be made that the file exists. If the file does not exist or is not
-readable, the function `bool error(file)' will return `true'.  The
-first character of the string `comment' specifies a comment character.
-If this character is encountered in a data file, the remainder of the
-line is ignored. When reading strings, a comment character followed
-immediately by another comment character is treated as a single literal
-comment character.
-
-   One can change the current working directory for read operations to
-the contents of the string `s' with the function `string cd(string s)',
-which returns the new working directory. If `string s' is empty, the
-path is reset to the value it had at program startup.
-
-   When reading pairs, the enclosing parenthesis are optional.  Strings
-are also read by assignment, by reading characters up to but not
-including a newline. In addition, `Asymptote' provides the function
-`string getc(file)' to read the next character (treating the comment
-character as an ordinary character) and return it as a string.
-
-   A file named `name' can be open for output with
-file output(string name="", bool update=false, string comment="#", string mode="");
- If `update=false', any existing data in the file will be erased and
-only write operations can be used on the file.  If `update=true', any
-existing data will be preserved, the position will be set to the
-end-of-file, and both reading and writing operations will be enabled.
-For security reasons, writing to files in directories other than the
-current directory is allowed only if the `-globalwrite' (or `-nosafe')
-command-line option is specified.  The function `string mktemp(string
-s)' may be used to create and return the name of a unique temporary
-file in the current directory based on the string `s'.
-
-   There are two special files: `stdin', which reads from the keyboard,
-and `stdout', which writes to the terminal. The implicit initializer
-for files is `null'.
-
-   Data of a built-in type `T' can be written to an output file by
-calling one of the functions 
-write(string s="", T x, suffix suffix=endl ... T[]);
-write(file file, string s="", T x, suffix suffix=none ... T[]);
-write(file file=stdout, string s="", explicit T[] x ... T[][]);
-write(file file=stdout, T[][]);
-write(file file=stdout, T[][][]);
-write(suffix suffix=endl);
-write(file file, suffix suffix=none);
- If `file' is not specified, `stdout' is used and terminated by default
-with a newline. If specified, the optional identifying string `s' is
-written before the data `x'.  An arbitrary number of data values may be
-listed when writing scalars or one-dimensional arrays. The `suffix' may
-be one of the following: `none' (do nothing), `flush' (output buffered
-data), `endl' (terminate with a newline and flush), `newl' (terminate
-with a newline), `DOSendl' (terminate with a DOS newline and flush),
-`DOSnewl' (terminate with a DOS newline), `tab' (terminate with a tab),
-or `comma' (terminate with a comma). Here are some simple examples of
-data output:
-file fout=output("test.txt");
-write(fout,1);                  // Writes "1"
-write(fout);                    // Writes a new line
-write(fout,"List: ",1,2,3);     // Writes "List: 1     2     3"
- A file may be opened with `mode="xdr"', to read or write double
-precision (64-bit) reals and single precision (32-bit) integers in Sun
-Microsystem's XDR (External Data Representation) portable binary format
-(available on all `UNIX' platforms).  Alternatively, a file may also be
-opened with `mode="binary"' to read or write double precision reals and
-single precision integers in the native (nonportable) machine binary
-format.  The virtual member functions `file singlereal(bool b=true)'
-and `file singleint(bool b=true)' be used to change the precision of
-real and integer I/O operations, respectively, for an XDR or binary
-file `f'.  Similarly, the function `file signedint(bool b=true)' can be
-used to modify the signedness of integer reads and writes for an XDR or
-binary file `f'.
-
-   The virtual members `name', `mode', `singlereal', `singleint', and
-`signedint' may be used to query the respective parameters for a given
-file.
-
-   One can test a file for end-of-file with the boolean function
-`eof(file)', end-of-line with `eol(file)', and for I/O errors with
-`error(file)'.  One can flush the output buffers with `flush(file)',
-clear a previous I/O error with `clear(file)', and close the file with
-`close(file)'. The function `int precision(file file=stdout, int
-digits=0)' sets the number of digits of output precision for `file' to
-`digits', provided `digits' is nonzero, and returns the previous
-precision setting. The function `int tell(file)' returns the current
-position in a file relative to the beginning.  The routine `seek(file
-file, int pos)' can be used to change this position, where a negative
-value for the position `pos' is interpreted as relative to the
-end-of-file. For example, one can rewind a file `file' with the command
-`seek(file,0)' and position to the final character in the file with
-`seek(file,-1)'.  The command `seekeof(file)' sets the position to the
-end of the file.
-
-   Assigning `settings.scroll=n' for a positive integer `n' requests a
-pause after every `n' output lines to `stdout'.  One may then press
-`Enter' to continue to the next `n' output lines, `s' followed by
-`Enter' to scroll without further interruption, or `q' followed by
-`Enter' to quit the current output operation. If `n' is negative, the
-output scrolls a page at a time (i.e. by one less than the current
-number of display lines). The default value, `settings.scroll=0',
-specifies continuous scrolling.
-
-   The routines 
-string getstring(string name="", string default="", string prompt="",
-                 bool store=true);
-int getint(string name="", int default=0, string prompt="",
-           bool store=true);
-real getreal(string name="", real default=0, string prompt="",
-             bool store=true);
-pair getpair(string name="", pair default=0, string prompt="",
-             bool store=true);
-triple gettriple(string name="", triple default=(0,0,0), string prompt="",
-                 bool store=true);
- defined in the module `plain' may be used to prompt for a value from
-`stdin' using the GNU `readline' library.  If `store=true', the history
-of values for `name' is stored in the file `".asy_history_"+name'
-(*note history::). The most recent value in the history will be used to
-provide a default value for subsequent runs.  The default value
-(initially `default') is displayed after `prompt'. These functions are
-based on the internal routines 
-string readline(string prompt="", string name="", bool tabcompletion=false);
-void saveline(string name, string value, bool store=true);
- Here, `readline' prompts the user with the default value formatted
-according to `prompt', while `saveline' is used to save the string
-`value' in a local history named `name', optionally storing the local
-history in a file `".asy_history_"+name'.
-
-   The routine `history(string name, int n=1)' can be used to look up
-the `n' most recent values (or all values up to `historylines' if
-`n=0') entered for string `name'.  The routine `history(int n=0)'
-returns the interactive history.  For example,
-write(output("transcript.asy"),history());
- outputs the interactive history to the file `transcript.asy'.
-
-   The function `int delete(string s)' deletes the file named by the
-string `s'. Unless the `-globalwrite' (or `-nosafe') option is enabled,
-the file must reside in the current directory.  The function `int
-rename(string from, string to)' may be used to rename file `from' to
-file `to'.  Unless the `-globalwrite' (or `-nosafe') option is enabled,
-this operation is restricted to the current directory.  The functions
-int convert(string args="", string file="", string format="");
-int animate(string args="", string file="", string format="");
- call the `ImageMagick' commands `convert' and `animate', respectively,
-with the arguments `args' and the file name constructed from the
-strings `file' and `format'.
-
-
-File: asymptote.info,  Node: Variable initializers,  Next: Structures,  Prev: Files,  Up: Programming
-
-6.7 Variable initializers
-=========================
-
-A variable can be assigned a value when it is declared, as in `int
-x=3;' where the variable `x' is assigned the value `3'.  As well as
-literal constants such as `3', arbitary expressions can be used as
-initializers, as in `real x=2*sin(pi/2);'.
-
-   A variable is not added to the namespace until after the initializer
-is evaluated, so for example, in
-int x=2;
-int x=5*x;
- the `x' in the initializer on the second line refers to the variable
-`x' declared on the first line.  The second line, then, declares a
-variable `x' shadowing the original `x' and initializes it to the value
-`10'.
-
-   Variables of most types can be declared without an explicit
-initializer and they will be initialized by the default initializer of
-that type:
-
-   * Variables of the numeric types `int', `real', and `pair' are all
-     initialized to zero; variables of type `triple' are initialized to
-     `O=(0,0,0)'.
-
-   * `boolean' variables are initialized to `false'.
-
-   * `string' variables are initialized to the empty string.
-
-   * `transform' variables are initialized to the identity
-     transformation.
-
-   * `path' and `guide' variables are initialized to `nullpath'.
-
-   * `pen' variables are initialized to the default pen.
-
-   * `frame' and `picture' variables are initialized to empty frames
-     and pictures, respectively.
-
-   * `file' variables are initialized to `null'.
-
-   The default initializers for user-defined array, structure, and
-function types are explained in their respective sections.  Some types,
-such as `code', do not have default initializers.  When a variable of
-such a type is introduced, the user must initialize it by explicitly
-giving it a value.
-
-   The default initializer for any type `T' can be redeclared by
-defining the function `T operator init()'.  For instance, `int'
-variables are usually initialized to zero, but in
-int operator init() {
-  return 3;
-}
-int y;
-
-the variable `y' is initialized to `3'.  This example was given for
-illustrative purposes; redeclaring the initializers of built-in types
-is not recommended. Typically, `operator init' is used to define
-sensible defaults for user-defined types.
-
-   The special type `var' may be used to infer the type of a variable
-from its initializer.  If the initializer is an expression of a unique
-type, then the variable will be defined with that type.  For instance,
-var x=5;
-var y=4.3;
-var reddash=red+dashed;
- is equivalent to
-int x=5;
-real y=4.3;
-pen reddash=red+dashed;
-
-   `var' may also be used with the extended `for' loop syntax.
-
-int[] a = {1,2,3};
-for (var x : a)
-  write(x);
-
-
-File: asymptote.info,  Node: Structures,  Next: Operators,  Prev: Variable initializers,  Up: Programming
-
-6.8 Structures
-==============
-
-Users may also define their own data types as structures, along with
-user-defined operators, much as in C++. By default, structure members
-are `public' (may be read and modified anywhere in the code), but may be
-optionally declared `restricted' (readable anywhere but writeable only
-inside the structure where they are defined) or `private' (readable and
-writable only inside the structure). In a structure definition, the
-keyword `this' can be used as an expression to refer to the enclosing
-structure. Any code at the top-level scope within the structure is
-executed on initialization.
-
-   Variables hold references to structures.  That is, in the example:
-struct T {
-  int x;
-}
-
-T foo=new T;
-T bar=foo;
-bar.x=5;
-
-   The variable `foo' holds a reference to an instance of the structure
-`T'.  When `bar' is assigned the value of `foo', it too now holds a
-reference to the same instance as `foo' does.  The assignment `bar.x=5'
-changes the value of the field `x' in that instance, so that `foo.x'
-will also be equal to `5'.
-
-   The expression `new T' creates a new instance of the structure `T'
-and returns a reference to that instance.  In creating the new
-instance, any code in the body of the record definition is executed.
-For example:
-int Tcount=0;
-struct T {
-  int x;
-  ++Tcount;
-}
-
-T foo=new T;
-
-   Here, the expression `new T' will produce a new instance of the
-class, but will also cause `Tcount' to be incremented, so that it keeps
-track of the number of instances produced.
-
-   The expression `null' can be cast to any structure type to yield a
-null reference, a reference that does not actually refer to any
-instance of the structure.  Trying to use a field of a null reference
-will cause an error.
-
-   The function `bool alias(T,T)' checks to see if two structure
-references refer to the same instance of the structure (or both to
-`null').  For example, in the example code at the start of the section,
-`alias(foo,bar)' would return true, but `alias(foo,new T)' would return
-false, as `new T' creates a new instance of the structure `T'.  The
-boolean operators `==' and `!=' are by default equivalent to `alias' and
-`!alias' respectively, but may be overwritten for a particular type
-(for example, to do a deep comparison).
-
-   After the definition of a structure `T', a variable of type `T' is
-initialized to a new instance (`new T') by default.  During the
-definition of the structure, however, variables of type `T' are
-initialized to `null' by default. This special behaviour is to avoid
-infinite recursion of creating new instances in code such as
-struct tree {
-  int value;
-  tree left;
-  tree right;
-}
-
-   Here is a simple example that illustrates the use of structures:
-struct S {
-  real a=1;
-  real f(real a) {return a+this.a;}
-}
-
-S s;                            // Initializes s with new S;
-
-write(s.f(2));                  // Outputs 3
-
-S operator + (S s1, S s2)
-{
-  S result;
-  result.a=s1.a+s2.a;
-  return result;
-}
-
-write((s+s).f(0));              // Outputs 2
-
-   It is often convenient to have functions that construct new
-instances of a structure.  Say we have a `Person' structure:
-struct Person {
-  string firstname;
-  string lastname;
-}
-
-Person joe=new Person;
-joe.firstname="Joe";
-joe.lastname="Jones";
- Creating a new Person is a chore; it takes three lines to create a new
-instance and to initialize its fields (that's still considerably less
-effort than creating a new person in real life, though).
-
-   We can reduce the work by defining a constructor function
-`Person(string,string)':
-struct Person {
-  string firstname;
-  string lastname;
-
-  static Person Person(string firstname, string lastname) {
-    Person p=new Person;
-    p.firstname=firstname;
-    p.lastname=lastname;
-    return p;
-  }
-}
-
-Person joe=Person.Person("Joe", "Jones");
-
-   While it is now easier than before to create a new instance, we still
-have to refer to the constructor by the qualified name `Person.Person'.
-If we add the line
-from Person unravel Person;
- immediately after the structure definition, then the constructor can
-be used without qualification: `Person joe=Person("Joe", "Jones");'.
-
-   The constructor is now easy to use, but it is quite a hassle to
-define.  If you write a lot of constructors, you will find that you are
-repeating a lot of code in each of them.  Fortunately, your friendly
-neighbourhood Asymptote developers have devised a way to automate much
-of the process.
-
-   If, in the body of a structure, Asymptote encounters the definition
-of a function of the form `void operator init(ARGS)',  it implicitly
-defines a constructor function of the arguments `ARGS' that uses the
-`void operator init' function to initialize a new instance of the
-structure.  That is, it essentially defines the following constructor
-(assuming the structure is called `Foo'):
-
-     static Foo Foo(ARGS) {
-       Foo instance=new Foo;
-       instance.operator init(ARGS);
-       return instance;
-     }
-
-   This constructor is also implicitly copied to the enclosing scope
-after the end of the structure definition, so that it can used
-subsequently without qualifying it by the structure name.  Our `Person'
-example can thus be implemented as:
-struct Person {
-  string firstname;
-  string lastname;
-
-  void operator init(string firstname, string lastname) {
-    this.firstname=firstname;
-    this.lastname=lastname;
-  }
-}
-
-Person joe=Person("Joe", "Jones");
-
-   The use of `operator init' to implicitly define constructors should
-not be confused with its use to define default values for variables
-(*note Variable initializers::).  Indeed, in the first case, the return
-type of the `operator init' must be `void' while in the second, it must
-be the (non-`void') type of the variable.
-
-   The function `cputime()' returns a structure `cputime' with
-cumulative CPU times broken down into the fields `parent.user',
-`parent.system', `child.user', and `child.system'. For convenience, the
-incremental fields `change.user' and `change.system' indicate the
-change in the corresponding total parent and child CPU times since the
-last call to `cputime()'. The function
-void write(file file=stdout, string s="", cputime c,
-           string format=cputimeformat, suffix suffix=none);
- displays the incremental user cputime followed by "u", the incremental
-system cputime followed by "s", the total user cputime followed by "U",
-and the total system cputime followed by "S".
-
-   Much like in C++, casting (*note Casts::) provides for an elegant
-implementation of structure inheritance, including virtual functions:
-struct parent {
-  real x;
-  void operator init(int x) {this.x=x;}
-  void virtual(int) {write(0);}
-  void f() {virtual(1);}
-}
-
-void write(parent p) {write(p.x);}
-
-struct child {
-  parent parent;
-  real y=3;
-  void operator init(int x) {parent.operator init(x);}
-  void virtual(int x) {write(x);}
-  parent.virtual=virtual;
-  void f()=parent.f;
-}
-
-parent operator cast(child child) {return child.parent;}
-
-parent p=parent(1);
-child c=child(2);
-
-write(c);                       // Outputs 2;
-
-p.f();                          // Outputs 0;
-c.f();                          // Outputs 1;
-
-write(c.parent.x);              // Outputs 2;
-write(c.y);                     // Outputs 3;
-
-   For further examples of structures, see `Legend' and `picture' in
-the `Asymptote' base module `plain'.
-
-
-File: asymptote.info,  Node: Operators,  Next: Implicit scaling,  Prev: Structures,  Up: Programming
-
-6.9 Operators
-=============
-
-* Menu:
-
-* Arithmetic & logical::        Basic mathematical operators
-* Self & prefix operators::     Increment and decrement
-* User-defined operators::      Overloading operators
-
-
-File: asymptote.info,  Node: Arithmetic & logical,  Next: Self & prefix operators,  Up: Operators
-
-6.9.1 Arithmetic & logical operators
-------------------------------------
-
-`Asymptote' uses the standard binary arithmetic operators.  However,
-when one integer is divided by another, both arguments are converted to
-real values before dividing and a real quotient is returned (since this
-is usually what is intended). The function `int quotient(int x, int y)'
-returns the greatest integer less than or equal to `x/y'. In all other
-cases both operands are promoted to the same type, which will also be
-the type of the result:
-`+'
-     addition 
-
-`-'
-     subtraction 
-
-`*'
-     multiplication 
-
-`/'
-     division 
-
-`%'
-     modulo; the result always has the same sign as the divisor.  In
-     particular, this makes `q*quotient(p,q)+p%q == p' for all integers
-     `p' and nonzero integers `q'.  
-
-`^'
-     power; if the exponent (second argument) is an int, recursive
-     multiplication is used; otherwise, logarithms and exponentials are
-     used (`**' is a synonym for `^').
-
-
-   The usual boolean operators are also defined:
-`=='
-     equals 
-
-`!='
-     not equals 
-
-`<'
-     less than 
-
-`<='
-     less than or equals 
-
-`>='
-     greater than or equals 
-
-`>'
-     greater than 
-
-`&&'
-     and (with conditional evaluation of right-hand argument) 
-
-`&'
-     and 
-
-`||'
-     or (with conditional evaluation of right-hand argument) 
-
-`|'
-     or 
-
-`^'
-     xor 
-
-`!'
-     not
-
-   `Asymptote' also supports the C-like conditional syntax: 
-bool positive=(pi > 0) ? true : false;
-
-   The function `T interp(T a, T b, real t)' returns `(1-t)*a+t*b' for
-nonintegral built-in arithmetic types `T'. If `a' and `b' are pens,
-they are first promoted to the same color space.
-
-   `Asymptote' also defines bitwise functions `int AND(int,int)', `int
-OR(int,int)', `int XOR(int,int)', `int NOT(int)', `int CLZ(int)' (count
-leading zeros), and `int CTZ(int)' (count trailing zeros).
-
-
-File: asymptote.info,  Node: Self & prefix operators,  Next: User-defined operators,  Prev: Arithmetic & logical,  Up: Operators
-
-6.9.2 Self & prefix operators
------------------------------
-
-As in C, each of the arithmetic operators `+', `-', `*', `/', `%', and
-`^' can be used as a self operator.  The prefix operators `++'
-(increment by one) and `--' (decrement by one) are also defined.  For
-example,
-int i=1;
-i += 2;
-int j=++i;
-
-is equivalent to the code
-int i=1;
-i=i+2;
-int j=i=i+1;
-
-   However, postfix operators like `i++' and `i--' are not defined
-(because of the inherent ambiguities that would arise with the `--'
-path-joining operator). In the rare instances where `i++' and `i--' are
-really needed, one can substitute the expressions `(++i-1)' and
-`(--i+1)', respectively.
-
-
-File: asymptote.info,  Node: User-defined operators,  Prev: Self & prefix operators,  Up: Operators
-
-6.9.3 User-defined operators
-----------------------------
-
-The following symbols may be used with `operator' to define or redefine
-operators on structures and built-in types:
-- + * / % ^ ! < > == != <= >= & | ^^ .. :: -- --- ++
-<< >> $ $$ @ @@
- The operators on the second line have precedence one higher than the
-boolean operators `<', `>', `<=', and `>='.
-
-   Guide operators like `..' may be overloaded, say, to write a user
-function that produces a new guide from a given guide:
-guide dots(... guide[] g)=operator ..;
-
-guide operator ..(... guide[] g) {
-  guide G;
-  if(g.length > 0) {
-    write(g[0]);
-    G=g[0];
-  }
-  for(int i=1; i < g.length; ++i) {
-    write(g[i]);
-    write();
-    G=dots(G,g[i]);
-  }
-  return G;
-}
-
-guide g=(0,0){up}..{SW}(100,100){NE}..{curl 3}(50,50)..(10,10);
-write("g=",g);
-
-
-File: asymptote.info,  Node: Implicit scaling,  Next: Functions,  Prev: Operators,  Up: Programming
-
-6.10 Implicit scaling
-=====================
-
-If a numeric literal is in front of certain types of expressions, then
-the two are multiplied:
-int x=2;
-real y=2.0;
-real cm=72/2.540005;
-
-write(3x);
-write(2.5x);
-write(3y);
-write(-1.602e-19 y);
-write(0.5(x,y));
-write(2x^2);
-write(3x+2y);
-write(3(x+2y));
-write(3sin(x));
-write(3(sin(x))^2);
-write(10cm);
-
-   This produces the output
-6
-5
-6
--3.204e-19
-(1,1)
-8
-10
-18
-2.72789228047704
-2.48046543129542
-283.464008929116
-
-
-File: asymptote.info,  Node: Functions,  Next: Arrays,  Prev: Implicit scaling,  Up: Programming
-
-6.11 Functions
-==============
-
-`Asymptote' functions are treated as variables with a signature
-(non-function variables have null signatures). Variables with the same
-name are allowed, so long as they have distinct signatures.
-
-   Functions arguments are passed by value. To pass an argument by
-reference, simply enclose it in a structure (*note Structures::).
-
-   Here are some significant features of `Asymptote' functions:
-
-  1. Variables with signatures (functions) and without signatures
-     (nonfunction variables) are distinct: int x, x();
-     x=5;
-     x=new int() {return 17;};
-     x=x();              // calls x() and puts the result, 17, in the scalar x
-
-  2. Traditional function definitions are allowed: int sqr(int x)
-     {
-       return x*x;
-     }
-     sqr=null;           // but the function is still just a variable.
-
-  3. Casting can be used to resolve ambiguities: int a, a(), b, b(); // Valid: creates four variables.
-     a=b;                // Invalid: assignment is ambiguous.
-     a=(int) b;          // Valid: resolves ambiguity.
-     (int) (a=b);        // Valid: resolves ambiguity.
-     (int) a=b;          // Invalid: cast expressions cannot be L-values.
-
-     int c();
-     c=a;                // Valid: only one possible assignment.
-
-  4. Anonymous (so-called "high-order") functions are also allowed: typedef int intop(int);
-     intop adder(int m)
-     {
-       return new int(int n) {return m+n;};
-     }
-     intop addby7=adder(7);
-     write(addby7(1));   // Writes 8.
-
-  5. One may redefine a function `f', even for calls to `f' in
-     previously declared functions, by assigning another (anonymous or
-     named) function to it. However, if `f' is overloaded by a new
-     function definition, previous calls will still access the original
-     version of `f', as illustrated in this example: void f() {
-       write("hi");
-     }
-
-     void g() {
-       f();
-     }
-
-     g(); // writes "hi"
-
-     f=new void() {write("bye");};
-
-     g(); // writes "bye"
-
-     void f() {write("overloaded");};
-
-     f(); // writes "overloaded"
-     g(); // writes "bye"
-
-  6. Anonymous functions can be used to redefine a function variable
-     that has been declared (and implicitly initialized to the null
-     function) but not yet explicitly defined: void f(bool b);
-
-     void g(bool b) {
-       if(b) f(b);
-       else write(b);
-     }
-
-     f=new void(bool b) {
-       write(b);
-       g(false);
-     };
-
-     g(true); // Writes true, then writes false.
-
-
-   `Asymptote' is the only language we know of that treats functions as
-variables, but allows overloading by distinguishing variables based on
-their signatures.
-
-   Functions are allowed to call themselves recursively. As in C++,
-infinite nested recursion will generate a stack overflow (reported as a
-segmentation fault, unless a fully working version of the GNU library
-`libsigsegv' (e.g. 2.4 or later) is installed at configuration time).
-
-* Menu:
-
-* Default arguments::           Default values can appear anywhere
-* Named arguments::             Assigning function arguments by keyword
-* Rest arguments::              Functions with a variable number of arguments
-* Mathematical functions::      Standard libm functions
-
-
-File: asymptote.info,  Node: Default arguments,  Next: Named arguments,  Up: Functions
-
-6.11.1 Default arguments
-------------------------
-
-`Asymptote' supports a more flexible mechanism for default function
-arguments than C++: they may appear anywhere in the function prototype.
-Because certain data types are implicitly cast to more sophisticated
-types (*note Casts::) one can often avoid ambiguities by ordering
-function arguments from the simplest to the most complicated.  For
-example, given
-real f(int a=1, real b=0) {return a+b;}
- then `f(1)' returns 1.0, but `f(1.0)' returns 2.0.
-
-   The value of a default argument is determined by evaluating the
-given `Asymptote' expression in the scope where the called function is
-defined.
-
-
-File: asymptote.info,  Node: Named arguments,  Next: Rest arguments,  Prev: Default arguments,  Up: Functions
-
-6.11.2 Named arguments
-----------------------
-
-It is sometimes difficult to remember the order in which arguments
-appear in a function declaration. Named (keyword) arguments make calling
-functions with multiple arguments easier. Unlike in the C and C++
-languages, an assignment in a function argument is interpreted as an
-assignment to a parameter of the same name in the function signature,
-_not within the local scope_. The command-line option `-d' may be used
-to check `Asymptote' code for cases where a named argument may be
-mistaken for a local assignment.
-
-   When matching arguments to signatures, first all of the keywords are
-matched, then the arguments without names are matched against the
-unmatched formals as usual. For example,
-int f(int x, int y) {
-  return 10x+y;
-}
-write(f(4,x=3));
- outputs 34, as `x' is already matched when we try to match the unnamed
-argument `4', so it gets matched to the next item, `y'.
-
-   For the rare occasions where it is desirable to assign a value to
-local variable within a function argument (generally _not_ a good
-programming practice), simply enclose the assignment in parentheses.
-For example, given the definition of `f' in the previous example,
-int x;
-write(f(4,(x=3)));
- is equivalent to the statements
-int x;
-x=3;
-write(f(4,3));
- and outputs 43.
-
-   Parameters can be specified as "keyword-only" by putting `keyword'
-immediately before the parameter name, as in `int f(int keyword x)' or
-`int f(int keyword x=77)'.  This forces the caller of the function to
-use a named argument to give a value for this parameter.  That is,
-`f(x=42)' is legal, but `f(25)' is not.  Keyword-only parameters must
-be listed after normal parameters in a function definition.
-
-   As a technical detail, we point out that, since variables of the same
-name but different signatures are allowed in the same scope, the code
-int f(int x, int x()) {
-  return x+x();
-}
-int seven() {return 7;}
- is legal in `Asymptote', with `f(2,seven)' returning 9.  A named
-argument matches the first unmatched formal of the same name, so
-`f(x=2,x=seven)' is an equivalent call, but `f(x=seven,2)' is not, as
-the first argument is matched to the first formal, and `int ()' cannot
-be implicitly cast to `int'.  Default arguments do not affect which
-formal a named argument is matched to, so if `f' were defined as
-int f(int x=3, int x()) {
-  return x+x();
-}
- then `f(x=seven)' would be illegal, even though `f(seven)' obviously
-would be allowed.
-
-
-File: asymptote.info,  Node: Rest arguments,  Next: Mathematical functions,  Prev: Named arguments,  Up: Functions
-
-6.11.3 Rest arguments
----------------------
-
-Rest arguments allow one to write functions that take a variable number
-of arguments:
-// This function sums its arguments.
-int sum(... int[] nums) {
-  int total=0;
-  for(int i=0; i < nums.length; ++i)
-    total += nums[i];
-  return total;
-}
-
-sum(1,2,3,4);                       // returns 10
-sum();                              // returns 0
-
-// This function subtracts subsequent arguments from the first.
-int subtract(int start ... int[] subs) {
-  for(int i=0; i < subs.length; ++i)
-    start -= subs[i];
-  return start;
-}
-
-subtract(10,1,2);                   // returns 7
-subtract(10);                       // returns 10
-subtract();                         // illegal
-
-   Putting an argument into a rest array is called _packing_.  One can
-give an explicit list of arguments for the rest argument, so `subtract'
-could alternatively be implemented as
-int subtract(int start ... int[] subs) {
-  return start - sum(... subs);
-}
-
-   One can even combine normal arguments with rest arguments:
-sum(1,2,3 ... new int[] {4,5,6});   // returns 21
- This builds a new six-element array that is passed to `sum' as `nums'.
-The opposite operation, _unpacking_, is not allowed:
-subtract(... new int[] {10, 1, 2});
- is illegal, as the start formal is not matched.
-
-   If no arguments are packed, then a zero-length array (as opposed to
-`null') is bound to the rest parameter. Note that default arguments are
-ignored for rest formals and the rest argument is not bound to a
-keyword.
-
-   In some cases, keyword-only parameters are helpful to avoid
-arguments intended for the rest parameter to be assigned to other
-parameters.  For example, here the use of `keyword' is to avoid
-`pnorm(1.0,2.0,0.3)' matching `1.0' to `p'.
-real pnorm(real keyword p=2.0 ... real[] v)
-{
-  return sum(v^p)^(1/p);
-}
-
-   The overloading resolution in `Asymptote' is similar to the function
-matching rules used in C++. Every argument match is given a score.
-Exact matches score better than matches with casting, and matches with
-formals (regardless of casting) score better than packing an argument
-into the rest array.  A candidate is maximal if all of the arguments
-score as well in it as with any other candidate.  If there is one
-unique maximal candidate, it is chosen; otherwise, there is an
-ambiguity error.
-
-int f(path g);
-int f(guide g);
-f((0,0)--(100,100)); // matches the second; the argument is a guide
-
-int g(int x, real y);
-int g(real x, int x);
-
-g(3,4); // ambiguous; the first candidate is better for the first argument,
-        // but the second candidate is better for the second argument
-
-int h(... int[] rest);
-int h(real x ... int[] rest);
-
-h(1,2); // the second definition matches, even though there is a cast,
-        // because casting is preferred over packing
-
-int i(int x ... int[] rest);
-int i(real x, real y ... int[] rest);
-
-i(3,4); // ambiguous; the first candidate is better for the first argument,
-        // but the second candidate is better for the second one
-
-
-File: asymptote.info,  Node: Mathematical functions,  Prev: Rest arguments,  Up: Functions
-
-6.11.4 Mathematical functions
------------------------------
-
-`Asymptote' has built-in versions of the standard `libm' mathematical
-real(real) functions `sin', `cos', `tan', `asin', `acos', `atan',
-`exp', `log', `pow10', `log10', `sinh', `cosh', `tanh', `asinh',
-`acosh', `atanh', `sqrt', `cbrt', `fabs', `expm1', `log1p', as well as
-the identity function `identity'.  `Asymptote' also defines the order
-`n' Bessel functions of the first kind `Jn(int n, real)' and second kind
-`Yn(int n, real)', as well as the gamma function `gamma', the error
-function `erf', and the complementary error function `erfc'. The
-standard real(real, real) functions `atan2', `hypot', `fmod',
-`remainder' are also included.
-
-   The functions `degrees(real radians)' and `radians(real degrees)'
-can be used to convert between radians and degrees. The function
-`Degrees(real radians)' returns the angle in degrees in the interval
-[0,360).  For convenience, `Asymptote' defines variants `Sin', `Cos',
-`Tan', `aSin', `aCos', and `aTan' of the standard trigonometric
-functions that use degrees rather than radians.  We also define complex
-versions of the `sqrt', `sin', `cos', `exp', `log', and `gamma'
-functions.
-
-   The functions `floor', `ceil', and `round' differ from their usual
-definitions in that they all return an int value rather than a real
-(since that is normally what one wants).  The functions `Floor',
-`Ceil', and `Round' are respectively similar, except that if the result
-cannot be converted to a valid int, they return `intMax' for positive
-arguments and `intMin' for negative arguments, rather than generating
-an integer overflow.  We also define a function `sgn', which returns
-the sign of its real argument as an integer (-1, 0, or 1).
-
-   There is an `abs(int)' function, as well as an `abs(real)' function
-(equivalent to `fabs(real)'), an `abs(pair)' function (equivalent to
-`length(pair)').
-
-   Random numbers can be seeded with `srand(int)' and generated with
-the `int rand()' function, which returns a random integer between 0 and
-the integer `randMax'. The `unitrand()' function returns a random
-number uniformly distributed in the interval [0,1].  A Gaussian random
-number generator `Gaussrand' and a collection of statistics routines,
-including `histogram', are provided in the base file `stats.asy'.  The
-functions `factorial(int n)', which returns n!, and `choose(int n, int
-k)', which returns n!/(k!(n-k)!), are also defined.
-
-   When configured with the GNU Scientific Library (GSL), available from
-`http://www.gnu.org/software/gsl/', `Asymptote' contains an internal
-module `gsl' that defines the airy functions `Ai(real)', `Bi(real)',
-`Ai_deriv(real)', `Bi_deriv(real)', `zero_Ai(int)', `zero_Bi(int)',
-`zero_Ai_deriv(int)', `zero_Bi_deriv(int)', the Bessel functions
-`I(int, real)', `K(int, real)', `j(int, real)', `y(int, real)',
-`i_scaled(int, real)', `k_scaled(int, real)', `J(real, real)', `Y(real,
-real)', `I(real, real)', `K(real, real)', `zero_J(real, int)', the
-elliptic functions `F(real, real)', `E(real, real)', and `P(real,
-real)', the Jacobi elliptic functions `real[] sncndn(real,real)', the
-exponential/trigonometric integrals `Ei', `Si', and `Ci', the Legendre
-polynomials `Pl(int, real)', and the Riemann zeta function
-`zeta(real)'. For example, to compute the sine integral `Si' of 1.0:
-import gsl;
-write(Si(1.0));
-
-   `Asymptote' also provides a few general purpose numerical routines:
-
-``real newton(int iterations=100, real f(real), real fprime(real), real x, bool verbose=false);''
-     Use Newton-Raphson iteration to solve for a root of a real-valued
-     differentiable function `f', given its derivative `fprime' and an
-     initial guess `x'. Diagnostics for each iteration are printed if
-     `verbose=true'.  If the iteration fails after the maximum allowed
-     number of loops (`iterations'), `realMax' is returned.
-
-``real newton(int iterations=100, real f(real), real fprime(real), real x1, real x2, bool verbose=false);''
-     Use bracketed Newton-Raphson bisection to solve for a root of a
-     real-valued differentiable function `f' within an interval
-     [`x1',`x2'] (on which the endpoint values of `f' have opposite
-     signs), given its derivative `fprime'. Diagnostics for each
-     iteration are printed if `verbose=true'.  If the iteration fails
-     after the maximum allowed number of loops (`iterations'),
-     `realMax' is returned.
-
-``real simpson(real f(real), real a, real b, real acc=realEpsilon, real dxmax=b-a)''
-     returns the integral of `f' from `a' to `b' using adaptive Simpson
-     integration.
-
-
-
-File: asymptote.info,  Node: Arrays,  Next: Casts,  Prev: Functions,  Up: Programming
-
-6.12 Arrays
-===========
-
-* Menu:
-
-* Slices::                      Python-style array slices
-
-   Appending `[]' to a built-in or user-defined type yields an array.
-The array element `i' of an array `A' can be accessed as `A[i]'.  By
-default, attempts to access or assign to an array element using a
-negative index generates an error. Reading an array element with an
-index beyond the length of the array also generates an error; however,
-assignment to an element beyond the length of the array causes the
-array to be resized to accommodate the new element.  One can also index
-an array `A' with an integer array `B': the array `A[B]' is formed by
-indexing array `A' with successive elements of array `B'.  A convenient
-Java-style shorthand exists for iterating over all elements of an
-array; see *note array iteration::.
-
-   The declaration
-real[] A;
-
-initializes `A' to be an empty (zero-length) array. Empty arrays should
-be distinguished from null arrays. If we say
-real[] A=null;
-
-then `A' cannot be dereferenced at all (null arrays have no length and
-cannot be read from or assigned to).
-
-   Arrays can be explicitly initialized like this:
-real[] A={0,1,2};
-
-   Array assignment in `Asymptote' does a shallow copy: only the
-pointer is copied (if one copy if modified, the other will be too).
-The `copy' function listed below provides a deep copy of an array.
-
-   Every array `A' of type `T[]' has the virtual members
-   * `int length',
-
-   * `int cyclic',
-
-   * `int[] keys',
-
-   * `T push(T x)',
-
-   * `void append(T[] a)',
-
-   * `T pop()',
-
-   * `void insert(int i ... T[] x)',
-
-   * `void delete(int i, int j=i)',
-
-   * `void delete()', and
-
-   * `bool initialized(int n)'.
-
-   The member `A.length' evaluates to the length of the array.  Setting
-`A.cyclic=true' signifies that array indices should be reduced modulo
-the current array length. Reading from or writing to a nonempty cyclic
-array never leads to out-of-bounds errors or array resizing.
-
-   The member `A.keys' evaluates to an array of integers containing the
-indices of initialized entries in the array in ascending order.  Hence,
-for an array of length `n' with all entries initialized, `A.keys'
-evaluates to `{0,1,...,n-1}'.  A new keys array is produced each time
-`A.keys' is evaluated.
-
-   The functions `A.push' and `A.append' append their arguments onto
-the end of the array, while `A.insert(int i ... T[] x)' inserts `x'
-into the array at index `i'.  For convenience `A.push' returns the
-pushed item.  The function `A.pop()' pops and returns the last element,
-while `A.delete(int i, int j=i)' deletes elements with indices in the
-range [`i',`j'], shifting the position of all higher-indexed elements
-down. If no arguments are given, `A.delete()' provides a convenient way
-of deleting all elements of `A'. The routine `A.initialized(int n)' can
-be used to examine whether the element at index `n' is initialized.
-Like all `Asymptote' functions, `push', `append', `pop', `insert',
-`delete', and `initialized' can be "pulled off" of the array and used
-on their own. For example,
-int[] A={1};
-A.push(2);         // A now contains {1,2}.
-A.append(A);       // A now contains {1,2,1,2}.
-int f(int)=A.push;
-f(3);              // A now contains {1,2,1,2,3}.
-int g()=A.pop;
-write(g());        // Outputs 3.
-A.delete(0);       // A now contains {2,1,2}.
-A.delete(0,1);       // A now contains {2}.
-A.insert(1,3);     // A now contains {2,3}.
-A.insert(1 ... A); // A now contains {2,2,3,3}
-A.insert(2,4,5);   // A now contains {2,2,4,5,3,3}.
-
-   The `[]' suffix can also appear after the variable name; this is
-sometimes convenient for declaring a list of variables and arrays of
-the same type:
-real a,A[];
- This declares `a' to be `real' and implicitly declares `A' to be of
-type `real[]'.
-
-   In the following list of built-in array functions, `T' represents a
-generic type. Note that the internal functions `alias', `array',
-`copy', `concat', `sequence', `map', and `transpose', which depend on
-type `T[]', are defined only after the first declaration of a variable
-of type `T[]'.
-
-`new T[]'
-     returns a new empty array of type `T[]';
-
-`new T[] {list}'
-     returns a new array of type `T[]' initialized with `list' (a comma
-     delimited list of elements).
-
-`new T[n]'
-     returns a new array of `n' elements of type `T[]'.  These `n'
-     array elements are not initialized unless they are arrays
-     themselves (in which case they are each initialized to empty
-     arrays).
-
-`T[] array(int n, T value, int depth=intMax)'
-     returns an array consisting of `n' copies of `value'.  If `value'
-     is itself an array, a deep copy of `value' is made for each entry.
-     If `depth' is specified, this deep copying only recurses to the
-     specified number of levels.
-
-`int[] sequence(int n)'
-     if `n >= 1' returns the array `{0,1,...,n-1}' (otherwise returns a
-     null array);
-
-`int[] sequence(int n, int m)'
-     if `m >= n' returns an array `{n,n+1,...,m}' (otherwise returns a
-     null array);
-
-`T[] sequence(T f(int), int n)'
-     if `n >= 1' returns the sequence `{f_i :i=0,1,...n-1}' given a
-     function `T f(int)' and integer `int n' (otherwise returns a null
-     array);
-
-`T[] map(T f(T), T[] a)'
-     returns the array obtained by applying the function `f' to each
-     element of the array `a'. This is equivalent to `sequence(new
-     T(int i) {return f(a[i]);},a.length)'.
-
-`int[] reverse(int n)'
-     if `n >= 1' returns the array `{n-1,n-2,...,0}' (otherwise returns
-     a null array);
-
-`int[] complement(int[] a, int n)'
-     returns the complement of the integer array `a' in
-     `{0,1,2,...,n-1}', so that `b[complement(a,b.length)]' yields the
-     complement of `b[a]'.
-
-`real[] uniform(real a, real b, int n)'
-     if `n >= 1' returns a uniform partition of `[a,b]' into `n'
-     subintervals (otherwise returns a null array);
-
-`int find(bool[], int n=1)'
-     returns the index of the `n'th `true' value or -1 if not found.
-     If `n' is negative, search backwards from the end of the array for
-     the `-n'th value;
-
-`int search(T[] a, T key)'
-     For built-in ordered types `T', searches a sorted array `a' of `n'
-     elements for k, returning the index `i' if `a[i] <= key < a[i+1]',
-     `-1' if `key' is less than all elements of `a', or `n-1' if `key'
-     is greater than or equal to the last element of `a'.
-
-`int search(T[] a, T key, bool less(T i, T j))'
-     searches an array `a' sorted in ascending order such that element
-     `i' precedes element `j' if `less(i,j)' is true;
-
-`T[] copy(T[] a)'
-     returns a deep copy of the array `a';
-
-`T[] concat(... T[][] a)'
-     returns a new array formed by concatenating the given
-     one-dimensional arrays given as arguments;
-
-`bool alias(T[] a, T[] b)'
-     returns `true' if the arrays `a' and `b' are identical;
-
-`T[] sort(T[] a)'
-     For built-in ordered types `T', returns a copy of `a' sorted in
-     ascending order;
-
-`T[][] sort(T[][] a)'
-     For built-in ordered types `T', returns a copy of `a' with the rows
-     sorted by the first column, breaking ties with successively higher
-     columns. For example: string[][] a={{"bob","9"},{"alice","5"},{"pete","7"},
-                   {"alice","4"}};
-     // Row sort (by column 0, using column 1 to break ties):
-     write(sort(a));
-
-     produces alice   4
-     alice   5
-     bob     9
-     pete    7
-
-`T[] sort(T[] a, bool less(T i, T j))'
-     returns a copy of `a' stably sorted in ascending order such that
-     element `i' precedes element `j' if `less(i,j)' is true.
-
-`T[][] transpose(T[][] a)'
-     returns the transpose of `a'.
-
-`T[][][] transpose(T[][][] a, int[] perm)'
-     returns the 3D transpose of `a' obtained by applying the
-     permutation `perm' of `new int[]{0,1,2}' to the indices of each
-     entry.
-
-`T sum(T[] a)'
-     For arithmetic types `T', returns the sum of `a'.  In the case
-     where `T' is `bool', the number of true elements in `a' is
-     returned.
-
-`T min(T[] a)'
-
-`T min(T[][] a)'
-
-`T min(T[][][] a)'
-     For built-in ordered types `T', returns the minimum element of `a'.
-
-`T max(T[] a)'
-
-`T max(T[][] a)'
-
-`T max(T[][][] a)'
-     For built-in ordered types `T', returns the maximum element of `a'.
-
-`T[] min(T[] a, T[] b)'
-     For built-in ordered types `T', and arrays `a' and `b' of the same
-     length, returns an array composed of the minimum of the
-     corresponding elements of `a' and `b'.
-
-`T[] max(T[] a, T[] b)'
-     For built-in ordered types `T', and arrays `a' and `b' of the same
-     length, returns an array composed of the maximum of the
-     corresponding elements of `a' and `b'.
-
-`pair[] pairs(real[] x, real[] y);'
-     For arrays `x' and `y' of the same length, returns the pair array
-     `sequence(new pair(int i) {return (x[i],y[i]);},x.length)'.
-
-`pair[] fft(pair[] a, int sign=1)'
-     returns the Fast Fourier Transform of `a' (if the optional `FFTW'
-     package is installed), using the given `sign'. Here is a simple
-     example: int n=4;
-     pair[] f=sequence(n);
-     write(f);
-     pair[] g=fft(f,-1);
-     write();
-     write(g);
-     f=fft(g,1);
-     write();
-     write(f/n);
-
-`real dot(real[] a, real[] b)'
-     returns the dot product of the vectors `a' and `b'.
-
-`pair dot(pair[] a, pair[] b)'
-     returns the complex dot product `sum(a*conj(b))' of the vectors
-     `a' and `b'.
-
-`real[] tridiagonal(real[] a, real[] b, real[] c, real[] f);'
-     Solve the periodic tridiagonal problem L`x'=`f' and return the
-     solution `x', where `f' is an n vector and L is the n \times n
-     matrix [ b[0] c[0]           a[0]   ]
-     [ a[1] b[1] c[1]             ]
-     [      a[2] b[2] c[2]        ]
-     [                ...         ]
-     [ c[n-1]       a[n-1] b[n-1] ]
-      For Dirichlet boundary conditions (denoted here by `u[-1]' and
-     `u[n]'), replace `f[0]' by `f[0]-a[0]u[-1]' and
-     `f[n-1]-c[n-1]u[n]'; then set `a[0]=c[n-1]=0'.
-
-`real[] solve(real[][] a, real[] b, bool warn=true)'
-     Solve the linear equation `a'x=`b' by LU decomposition and return
-     the solution x, where `a' is an n \times n matrix and `b' is an
-     array of length n.  For example: import math;
-     real[][] a={{1,-2,3,0},{4,-5,6,2},{-7,-8,10,5},{1,50,1,-2}};
-     real[] b={7,19,33,3};
-     real[] x=solve(a,b);
-     write(a); write();
-     write(b); write();
-     write(x); write();
-     write(a*x);
-      If `a' is a singular matrix and `warn' is `false', return an
-     empty array.  If the matrix `a' is tridiagonal, the routine
-     `tridiagonal' provides a more efficient algorithm (*note
-     tridiagonal::).
-
-`real[][] solve(real[][] a, real[][] b, bool warn=true)'
-     Solve the linear equation `a'x=`b' and return the solution x,
-     where `a' is an n \times n matrix and `b' is an n \times m matrix.
-     If `a' is a singular matrix and `warn' is `false', return an empty
-     matrix.
-
-`real[][] identity(int n);'
-     returns the n \times n identity matrix.
-
-`real[][] diagonal(... real[] a)'
-     returns the diagonal matrix with diagonal entries given by a.
-
-`real[][] inverse(real[][] a)'
-     returns the inverse of a square matrix `a'.
-
-``real[] quadraticroots(real a, real b, real c);''
-     This numerically robust solver returns the real roots of the
-     quadratic equation ax^2+bx+c=0, in ascending order. Multiple roots
-     are listed separately.
-
-``pair[] quadraticroots(explicit pair a, explicit pair b, explicit pair c);''
-     This numerically robust solver returns the complex roots of the
-     quadratic equation ax^2+bx+c=0.
-
-``real[] cubicroots(real a, real b, real c, real d);''
-     This numerically robust solver returns the real roots of the cubic
-     equation ax^3+bx^2+cx+d=0. Multiple roots are listed separately.
-
-
-   `Asymptote' includes a full set of vectorized array instructions for
-arithmetic (including self) and logical operations. These
-element-by-element instructions are implemented in C++ code for speed.
-Given
-real[] a={1,2};
-real[] b={3,2};
- then `a == b' and `a >= 2' both evaluate to the vector `{false, true}'.  To
-test whether all components of `a' and `b' agree, use the boolean
-function `all(a == b)'. One can also use conditionals like `(a >= 2) ?
-a : b', which returns the array `{3,2}', or `write((a >= 2) ? a :
-null', which returns the array `{2}'.
-
-   All of the standard built-in `libm' functions of signature
-`real(real)' also take a real array as an argument, effectively like an
-implicit call to `map'.
-
-   As with other built-in types, arrays of the basic data types can be
-read in by assignment. In this example, the code
-file fin=input("test.txt");
-real[] A=fin;
-
-reads real values into `A' until the end-of-file is reached (or an I/O
-error occurs).
-
-   The virtual members `dimension', `line', `csv', `word', and `read'
-of a file are useful for reading arrays.  For example, if line mode is
-set with `file line(bool b=true)', then reading will stop once the end
-of the line is reached instead
-file fin=input("test.txt");
-real[] A=fin.line();
-
-   Since string reads by default read up to the end of line anyway,
-line mode normally has no effect on string array reads.  However, there
-is a white-space delimiter mode for reading strings, `file word(bool
-b=true)', which causes string reads to respect white-space delimiters,
-instead of the default end-of-line delimiter:
-file fin=input("test.txt").line().word();
-real[] A=fin;
-
-   Another useful mode is comma-separated-value mode, `file csv(bool
-b=true)', which causes reads to respect comma delimiters:
-file fin=csv(input("test.txt"));
-real[] A=fin;
-
-   To restrict the number of values read, use the `file dimension(int)'
-function:
-file fin=input("test.txt");
-real[] A=dimension(fin,10);
-
-   This reads 10 values into A, unless end-of-file (or end-of-line in
-line mode) occurs first. Attempting to read beyond the end of the file
-will produce a runtime error message. Specifying a value of 0 for the
-integer limit is equivalent to the previous example of reading until
-end-of-file (or end-of-line in line mode) is encountered.
-
-   Two- and three-dimensional arrays of the basic data types can be read
-in like this:
-file fin=input("test.txt");
-real[][] A=fin.dimension(2,3);
-real[][][] B=fin.dimension(2,3,4);
- Again, an integer limit of zero means no restriction.
-
-   Sometimes the array dimensions are stored with the data as integer
-fields at the beginning of an array. Such 1, 2, or 3 dimensional arrays
-can be read in with the virtual member functions `read(1)', `read(2)',
-or `read(3)', respectively:
-file fin=input("test.txt");
-real[] A=fin.read(1);
-real[][] B=fin.read(2);
-real[][][] C=fin.read(3);
-
-   One, two, and three-dimensional arrays of the basic data types can be
-output with the functions `write(file,T[])', `write(file,T[][])',
-`write(file,T[][][])', respectively.
-
-
-File: asymptote.info,  Node: Slices,  Up: Arrays
-
-6.12.1 Slices
--------------
-
-Asymptote allows a section of an array to be addressed as a slice using
-a Python-like syntax.  If `A' is an array, the expression `A[m:n]'
-returns a new array consisting of the elements of `A' with indices from
-`m' up to but not including `n'. For example,
-int[] x={0,1,2,3,4,5,6,7,8,9};
-int[] y=x[2:6];  // y={2,3,4,5};
-int[] z=x[5:10]; // z={5,6,7,8,9};
-
-   If the left index is omitted, it is taken be `0'.  If the right
-index is omitted it is taken to be the length of the array.  If both
-are omitted, the slice then goes from the start of the array to the
-end, producing a non-cyclic deep copy of the array.  For example:
-int[] x={0,1,2,3,4,5,6,7,8,9};
-int[] y=x[:4];  // y={0,1,2,3}
-int[] z=x[5:];  // z={5,6,7,8,9}
-int[] w=x[:];   // w={0,1,2,3,4,5,6,7,8,9}, distinct from array x.
-
-   If A is a non-cyclic array, it is illegal to use negative values for
-either of the indices.  If the indices exceed the length of the array,
-however, they are politely truncated to that length.
-
-   For cyclic arrays, the slice `A[m:n]' still consists of the cells
-with indices in the set [`m',`n'), but now negative values and values
-beyond the length of the array are allowed.  The indices simply wrap
-around.  For example:
-
-int[] x={0,1,2,3,4,5,6,7,8,9};
-x.cyclic=true;
-int[] y=x[8:15];  // y={8,9,0,1,2,3,4}.
-int[] z=x[-5:5];  // z={5,6,7,8,9,0,1,2,3,4}
-int[] w=x[-3:17]; // w={7,8,9,0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6}
-
-   Notice that with cyclic arrays, it is possible to include the same
-element of the original array multiple times within a slice.
-Regardless of the original array, arrays produced by slices are always
-non-cyclic.
-
-   If the left and right indices of a slice are the same, the result is
-an empty array.  If the array being sliced is empty, the result is an
-empty array.  Any slice with a left index greater than its right index
-will yield an error.
-
-   Slices can also be assigned to, changing the value of the original
-array.  If the array being assigned to the slice has a different length
-than the slice itself, elements will be inserted or removed from the
-array to accommodate it. For instance:
-string[] toppings={"mayo", "salt", "ham", "lettuce"};
-toppings[0:2]=new string[] {"mustard", "pepper"};
-    // Now toppings={"mustard", "pepper", "ham", "lettuce"}
-toppings[2:3]=new string[] {"turkey", "bacon" };
-    // Now toppings={"mustard", "pepper", "turkey", "bacon", "lettuce"}
-toppings[0:3]=new string[] {"tomato"};
-    // Now toppings={"tomato", "bacon", "lettuce"}
-
-   If an array is assigned to a slice of itself, a copy of the original
-array is assigned to the slice.  That is, code such as `x[m:n]=x' is
-equivalent to `x[m:n]=copy(x)'.  One can use the shorthand `x[m:m]=y'
-to insert the contents of the array `y' into the array `x' starting at
-the location just before `x[m]'.
-
-   For a cyclic array, a slice is bridging if it addresses cells up to
-the end of the array and then continues on to address cells at the
-start of the array.  For instance, if `A' is a cyclic array of length
-10, `A[8:12]', `A[-3:1]', and `A[5:25]' are bridging slices whereas
-`A[3:7]', `A[7:10]', `A[-3:0]' and `A[103:107]' are not.  Bridging
-slices can only be assigned to if the number of elements in the slice
-is exactly equal to the number of elements we are assigning to it.
-Otherwise, there is no clear way to decide which of the new entries
-should be `A[0]' and an error is reported.  Non-bridging slices may be
-assigned an array of any length.
-
-   For a cyclic array `A' an expression of the form
-`A[A.length:A.length]' is equivalent to the expression `A[0:0]' and so
-assigning to this slice will insert values at the start of the array.
-`A.append()' can be used to insert values at the end of the array.
-
-   It is illegal to assign to a slice of a cyclic array that repeats
-any of the cells.
-
-
-File: asymptote.info,  Node: Casts,  Next: Import,  Prev: Arrays,  Up: Programming
-
-6.13 Casts
-==========
-
-`Asymptote' implicitly casts `int' to `real', `int' to `pair', `real'
-to `pair', `pair' to `path', `pair' to `guide', `path' to `guide',
-`guide' to `path', `real' to `pen', `pair[]' to `guide[]', `pair[]' to
-`path[]', `path' to `path[]', and `guide' to `path[]', along with
-various three-dimensional casts defined in `three.asy'.  Implicit casts
-are automatically attempted on assignment and when trying to match
-function calls with possible function signatures. Implicit casting can
-be inhibited by declaring individual arguments `explicit' in the
-function signature, say to avoid an ambiguous function call in the
-following example, which outputs 0:
-int f(pair a) {return 0;}
-int f(explicit real x) {return 1;}
-
-write(f(0));
-
-   Other conversions, say `real' to `int' or `real' to `string',
-require an explicit cast:
-int i=(int) 2.5;
-string s=(string) 2.5;
-
-real[] a={2.5,-3.5};
-int[] b=(int []) a;
-write(stdout,b);     // Outputs 2,-3
-
-   Casting to user-defined types is also possible using `operator cast':
-struct rpair {
-  real radius;
-  real angle;
-}
-
-pair operator cast(rpair x) {
-  return (x.radius*cos(x.angle),x.radius*sin(x.angle));
-}
-
-rpair x;
-x.radius=1;
-x.angle=pi/6;
-
-write(x);            // Outputs (0.866025403784439,0.5)
-
-   One must use care when defining new cast operators. Suppose that in
-some code one wants all integers to represent multiples of 100. To
-convert them to reals, one would first want to multiply them by 100.
-However, the straightforward implementation
-real operator cast(int x) {return x*100;}
- is equivalent to an infinite recursion, since the result `x*100' needs
-itself to be cast from an integer to a real. Instead, we want to use
-the standard conversion of int to real:
-real convert(int x) {return x*100;}
-real operator cast(int x)=convert;
-
-   Explicit casts are implemented similarly, with `operator ecast'.
-
-
-File: asymptote.info,  Node: Import,  Next: Static,  Prev: Casts,  Up: Programming
-
-6.14 Import
-===========
-
-While `Asymptote' provides many features by default, some applications
-require specialized features contained in external `Asymptote' modules.
-For instance, the lines
-access graph;
-graph.axes();
- draw x and y axes on a two-dimensional graph.  Here, the command looks
-up the module under the name `graph' in a global dictionary of modules
-and puts it in a new variable named `graph'.  The module is a
-structure, and we can refer to its fields as we usually would with a
-structure.
-
-   Often, one wants to use module functions without having to specify
-the module name.  The code
-from graph access axes;
- adds the `axes' field of `graph' into the local name space, so that
-subsequently, one can just write `axes()'.  If the given name is
-overloaded, all types and variables of that name are added.  To add
-more than one name, just use a comma-separated list:
-from graph access axes, xaxis, yaxis;
- Wild card notation can be used to add all non-private fields and types
-of a module to the local name space:
-
-from graph access *;
-
-   Similarly, one can add the non-private fields and types of a
-structure to the local environment with the `unravel' keyword:
-struct matrix {
-  real a,b,c,d;
-}
-
-real det(matrix m) {
-  unravel m;
-  return a*d-b*c;
-}
- Alternatively, one can unravel selective fields:
-real det(matrix m) {
-  from m unravel a,b,c as C,d;
-  return a*d-b*C;
-}
-
-   The command
-import graph;
- is a convenient abbreviation for the commands
-access graph;
-unravel graph;
- That is, `import graph' first loads a module into a structure called
-`graph' and then adds its non-private fields and types to the local
-environment. This way, if a member variable (or function) is
-overwritten with a local variable (or function of the same signature),
-the original one can still be accessed by qualifying it with the module
-name.
-
-   Wild card importing will work fine in most cases, but one does not
-usually know all of the internal types and variables of a module, which
-can also change as the module writer adds or changes features of the
-module.  As such, it is prudent to add `import' commands at the start
-of an `Asymptote' file, so that imported names won't shadow locally
-defined functions.  Still, imported names may shadow other imported
-names, depending on the order in which they were imported, and imported
-functions may cause overloading resolution problems if they have the
-same name as local functions defined later.
-
-   To rename modules or fields when adding them to the local
-environment, use `as':
-access graph as graph2d;
-from graph access xaxis as xline, yaxis as yline;
-
-   The command
-import graph as graph2d;
- is a convenient abbreviation for the commands
-access graph as graph2d;
-unravel graph2d;
-
-   Except for a few built-in modules, such as `settings', all modules
-are implemented as `Asymptote' files.  When looking up a module that
-has not yet been loaded, `Asymptote' searches the standard search paths
-(*note Search paths::) for the matching file.  The file corresponding
-to that name is read and the code within it is interpreted as the body
-of a structure defining the module.
-
-   If the file name contains nonalphanumeric characters, enclose it
-with quotation marks:
-
-`access "/usr/local/share/asymptote/graph.asy" as graph;'
-
-`from "/usr/local/share/asymptote/graph.asy" access axes;'
-
-`import "/usr/local/share/asymptote/graph.asy" as graph;'
-
-   It is an error if modules import themselves (or each other in a
-cycle).  The module name to be imported must be known at compile time.
-
-   However, you can import an `Asymptote' module determined by the
-string `s' at runtime like this:
-eval("import "+s,true);
-
-   To conditionally execute an array of asy files, use
-void asy(string format, bool overwrite ... string[] s);
- The file will only be processed, using output format `format', if
-overwrite is `true' or the output file is missing.
-
-   One can evaluate an `Asymptote' expression (without any return
-value, however) contained in the string `s' with: 
-void eval(string s, bool embedded=false);
- It is not necessary to terminate the string `s' with a semicolon.  If
-`embedded' is `true', the string will be evaluated at the top level of
-the current environment.  If `embedded' is `false' (the default), the
-string will be evaluated in an independent environment, sharing the same
-`settings' module (*note settings::).
-
-   One can evaluate arbitrary `Asymptote' code (which may contain
-unescaped quotation marks) with the command
-void eval(code s, bool embedded=false);
- Here `code' is a special type used with `quote {}' to enclose
-`Asymptote code' like this:
-real a=1;
-code s=quote {
-  write(a);
-};
-eval(s,true);        // Outputs 1
-
-   To include the contents of an existing file `graph' verbatim (as if
-the contents of the file were inserted at that point), use one of the
-forms:
-include graph;
-
-`include "/usr/local/share/asymptote/graph.asy";'
-
-   To list all global functions and variables defined in a module named
-by the contents of the string `s', use the function
-void list(string s, bool imports=false);
- Imported global functions and variables are also listed if `imports'
-is `true'.
-
-
-File: asymptote.info,  Node: Static,  Prev: Import,  Up: Programming
-
-6.15 Static
-===========
-
-Static qualifiers allocate the memory address of a variable in a higher
-enclosing level.
-
-   For a function body, the variable is allocated in the block where the
-function is defined; so in the code
-struct s {
-  int count() {
-    static int c=0;
-    ++c;
-    return c;
-  }
-}
-
-there is one instance of the variable `c' for each object `s' (as
-opposed to each call of `count').
-
-   Similarly, in
-int factorial(int n) {
-  int helper(int k) {
-    static int x=1;
-    x *= k;
-    return k == 1 ? x : helper(k-1);
-  }
-  return helper(n);
-}
-
-there is one instance of `x' for every call to `factorial' (and not for
-every call to `helper'), so this is a correct, but ugly, implementation
-of factorial.
-
-   Similarly, a static variable declared within a structure is
-allocated in the block where the structure is defined. Thus,
-struct A {
-  struct B {
-    static pair z;
-  }
-}
-
-creates one object `z' for each object of type `A' created.
-
-   In this example,
-int pow(int n, int k) {
-  struct A {
-    static int x=1;
-    void helper() {
-      x *= n;
-    }
-  }
-  for(int i=0; i < k; ++i) {
-    A a;
-    a.helper();
-  }
-  return A.x;
-}
-
-there is one instance of `x' for each call to `pow', so this is an ugly
-implementation of exponentiation.
-
-   Loop constructs allocate a new frame in every iteration.  This is so
-that higher-order functions can refer to variables of a specific
-iteration of a loop:
-void f();
-for(int i=0; i < 10; ++i) {
-  int x=i;
-  if(x==5) {
-    f=new void () { write(x); }
-  }
-}
-f();
-
-   Here, every iteration of the loop has its own variable `x', so `f()'
-will write `5'.  If a variable in a loop is declared static, it will be
-allocated where the enclosing function or structure was defined (just
-as if it were declared static outside of the loop).  For instance, in:
-void f() {
-  static int x;
-  for(int i=0; i < 10; ++i) {
-    static int y;
-  }
-}
- both `x' and `y' will be allocated in the same place, which is also
-where `f' is also allocated.
-
-   Statements may also be declared static, in which case they are run
-at the place where the enclosing function or structure is defined.
-Declarations or statements not enclosed in a function or structure
-definition are already at the top level, so static modifiers are
-meaningless.  A warning is given in such a case.
-
-   Since structures can have static fields, it is not always clear for
-a qualified name whether the qualifier is a variable or a type.  For
-instance, in:
-
-struct A {
-  static int x;
-}
-pair A;
-
-int y=A.x;
- does the `A' in `A.x' refer to the structure or to the pair variable.
-It is the convention in Asymptote that, if there is a non-function
-variable with the same name as the qualifier, the qualifier refers to
-that variable, and not to the type.  This is regardless of what fields
-the variable actually possesses.
-
-
-File: asymptote.info,  Node: LaTeX usage,  Next: Base modules,  Prev: Programming,  Up: Top
-
-7 `LaTeX' usage
-***************
-
-`Asymptote' comes with a convenient `LaTeX' style file `asymptote.sty'
-that makes `LaTeX' `Asymptote'-aware. Entering `Asymptote' code
-directly into the `LaTeX' source file, at the point where it is needed,
-keeps figures organized and avoids the need to invent new file names
-for each figure. Simply add the line `\usepackage{asymptote}' at the
-beginning of your file and enclose your `Asymptote' code within a
-`\begin{asy}...\end{asy}' environment. As with the `LaTeX' `comment'
-environment, the `\end{asy}' command must appear on a line by itself,
-with no trailing commands/comments.  A blank line is not allowed after
-`\begin{asy}'.
-
-   The sample `LaTeX' file below, named `latexusage.tex', can be run as
-follows:
-latex latexusage
-asy latexusage-*.asy
-latex latexusage
-
-or
-pdflatex latexusage
-asy latexusage-*.asy
-pdflatex latexusage
- To switch between using inline Asymptote code with `latex' and
-`pdflatex' you may first need to remove the files `latexusage-*.tex'.
-
-   An even better method for processing a `LaTeX' file with embedded
-`Asymptote' code is to use the `latexmk' utility from
-
-     `http://www.ctan.org/tex-archive/support/latexmk/'
-   after putting the contents of
-`http://asymptote.svn.sourceforge.net/viewvc/asymptote/trunk/asymptote/doc/latexmkrc'
-in a file `latexmkrc' in the same directory. The command
-latexmk -pdf latexusage
- will then call `Asymptote' automatically, recompiling only the figures
-that have changed. Since each figure is compiled in a separate system
-process, this method also tends to use less memory.  To store the
-figures in a separate directory named `asy', one can define
-\def\asydir{asy}
- in `latexusage.tex' and put the contents of
-`http://asymptote.svn.sourceforge.net/viewvc/asymptote/trunk/asymptote/doc/latexmkrc_asydir'
-in a file `latexmkrc' in the same directory.  External `Asymptote' code
-in `filename.asy' should be included with 
-\asyinclude[<options>]{<filename.asy>}
- so that `latexmk' will recognize when the code is changed. Note that
-`latemk' requires `perl', available from `http://www.perl.org/'.
-
-   One can specify `width', `height', `keepAspect', `viewportwidth',
-`viewportheight', `attach', and `inline'.  `keyval'-style options to
-the `asy' and `asyinclude' environments.  Three-dimensional PRC files
-may either be embedded within the page (the default) or attached as
-annotated (but printable) attachments, using the `attach' option and
-the `attachfile2' (or older `attachfile') `LaTeX' package.  The
-`inline' option generates inline `LaTeX' code instead of EPS or PDF
-files. This makes 2D LaTeX symbols visible to the
-`\begin{asy}...\end{asy}' environment.  In this mode, Asymptote
-correctly aligns 2D LaTeX symbols defined outside of
-`\begin{asy}...\end{asy}', but treats their size as zero; an optional
-second string can be given to `Label' to provide an estimate of the
-unknown label size.
-
-   Note that if the `latex' TeX engine is used with the `inline'
-option, labels might not show up in DVI viewers that cannot handle raw
-`PostScript' code. One can use `dvips'/`dvipdf' to produce
-`PostScript'/PDF output (we recommend using the modified version of
-`dvipdf' in the `Asymptote' patches directory, which accepts the `dvips
--z' hyperdvi option).
-
-   Here now is `latexusage.tex':
-
-\documentclass[12pt]{article}
-
-% Use this form to include EPS (latex) or PDF (pdflatex) files:
-\usepackage{asymptote}
-
-% Use this form with latex or pdflatex to include inline LaTeX code by default:
-%\usepackage[inline]{asymptote}
-
-% Use this form with latex or pdflatex to create PDF attachments by default:
-%\usepackage[attach]{asymptote}
-
-% Enable this line to support the attach option:
-%\usepackage[dvips]{attachfile2}
-
-\begin{document}
-
-% Optional subdirectory for asy files (no spaces):
-\def\asydir{}
-
-\begin{asydef}
-// Global Asymptote definitions can be put here.
-import three;
-usepackage("bm");
-texpreamble("\def\V#1{\bm{#1}}");
-// One can globally override the default toolbar settings here:
-// settings.toolbar=true;
-\end{asydef}
-
-Here is a venn diagram produced with Asymptote, drawn to width 4cm:
-
-\def\A{A}
-\def\B{\V{B}}
-
-%\begin{figure}
-\begin{center}
-\begin{asy}
-size(4cm,0);
-pen colour1=red;
-pen colour2=green;
-
-pair z0=(0,0);
-pair z1=(-1,0);
-pair z2=(1,0);
-real r=1.5;
-path c1=circle(z1,r);
-path c2=circle(z2,r);
-fill(c1,colour1);
-fill(c2,colour2);
-
-picture intersection=new picture;
-fill(intersection,c1,colour1+colour2);
-clip(intersection,c2);
-
-add(intersection);
-
-draw(c1);
-draw(c2);
-
-//draw("$\A$",box,z1);              // Requires [inline] package option.
-//draw(Label("$\B$","$B$"),box,z2); // Requires [inline] package option.
-draw("$A$",box,z1);
-draw("$\V{B}$",box,z2);
-
-pair z=(0,-2);
-real m=3;
-margin BigMargin=Margin(0,m*dot(unit(z1-z),unit(z0-z)));
-
-draw(Label("$A\cap B$",0),conj(z)--z0,Arrow,BigMargin);
-draw(Label("$A\cup B$",0),z--z0,Arrow,BigMargin);
-draw(z--z1,Arrow,Margin(0,m));
-draw(z--z2,Arrow,Margin(0,m));
-
-shipout(bbox(0.25cm));
-\end{asy}
-%\caption{Venn diagram}\label{venn}
-\end{center}
-%\end{figure}
-
-Each graph is drawn in its own environment. One can specify the width
-and height to \LaTeX\ explicitly. This 3D example can be viewed
-interactively either with Adobe Reader or Asymptote's fast OpenGL-based
-renderer. To support {\tt latexmk}, 3D figures should specify
-\verb+inline=true+. It is sometimes desirable to embed 3D files as annotated
-attachments; this requires the \verb+attach=true+ option as well as the
-\verb+attachfile2+ \LaTeX\ package.
-\begin{center}
-\begin{asy}[height=4cm,inline=true,attach=false,viewportwidth=\linewidth]
-currentprojection=orthographic(5,4,2);
-draw(unitcube,blue);
-label("$V-E+F=2$",(0,1,0.5),3Y,blue+fontsize(17pt));
-\end{asy}
-\end{center}
-
-One can also scale the figure to the full line width:
-\begin{center}
-\begin{asy}[width=\the\linewidth,inline=true]
-pair z0=(0,0);
-pair z1=(2,0);
-pair z2=(5,0);
-pair zf=z1+0.75*(z2-z1);
-
-draw(z1--z2);
-dot(z1,red+0.15cm);
-dot(z2,darkgreen+0.3cm);
-label("$m$",z1,1.2N,red);
-label("$M$",z2,1.5N,darkgreen);
-label("$\hat{\ }$",zf,0.2*S,fontsize(24pt)+blue);
-
-pair s=-0.2*I;
-draw("$x$",z0+s--z1+s,N,red,Arrows,Bars,PenMargins);
-s=-0.5*I;
-draw("$\bar{x}$",z0+s--zf+s,blue,Arrows,Bars,PenMargins);
-s=-0.95*I;
-draw("$X$",z0+s--z2+s,darkgreen,Arrows,Bars,PenMargins);
-\end{asy}
-\end{center}
-\end{document}
-
-
-File: asymptote.info,  Node: Base modules,  Next: Options,  Prev: LaTeX usage,  Up: Top
-
-8 Base modules
-**************
-
-`Asymptote' currently ships with the following base modules:
-
-* Menu:
-
-* plain::                       Default `Asymptote' base file
-* simplex::                     Linear programming: simplex method
-* math::                        Extend `Asymptote''s math capabilities
-* interpolate::                 Interpolation routines
-* geometry::                    Geometry routines
-* trembling::                   Wavy lines
-* stats::                       Statistics routines and histograms
-* patterns::                    Custom fill and draw patterns
-* markers::                     Custom path marker routines
-* tree::                        Dynamic binary search tree
-* binarytree::                  Binary tree drawing module
-* drawtree::                    Tree drawing module
-* syzygy::                      Syzygy and braid drawing module
-* feynman::                     Feynman diagrams
-* roundedpath::                 Round the sharp corners of paths
-* animation::                   Embedded PDF and MPEG movies
-* embed::                       Embedding movies, sounds, and 3D objects
-* slide::                       Making presentations with `Asymptote'
-* MetaPost::                    `MetaPost' compatibility routines
-* unicode::                     Accept `unicode' (UTF-8) characters
-* latin1::                      Accept `ISO 8859-1' characters
-* babel::                       Interface to `LaTeX' `babel' package
-* labelpath::                   Drawing curved labels
-* labelpath3::                  Drawing curved labels in 3D
-* annotate::                    Annotate your PDF files
-* CAD::                         2D CAD pen and measurement functions (DIN 15)
-* graph::                       2D linear & logarithmic graphs
-* palette::                     Color density images and palettes
-* three::                       3D vector graphics
-* obj::                         3D obj files
-* graph3::                      3D linear & logarithmic graphs
-* grid3::                       3D grids
-* solids::                      3D solid geometry
-* tube::                        3D rotation minimizing tubes
-* flowchart::                   Flowchart drawing routines
-* contour::                     Contour lines
-* contour3::                    Contour surfaces
-* slopefield::                  Slope fields
-* ode::                         Ordinary differential equations
-
-
-File: asymptote.info,  Node: plain,  Next: simplex,  Up: Base modules
-
-8.1 `plain'
-===========
-
-This is the default `Asymptote' base file, which defines key parts of
-the drawing language (such as the `picture' structure).
-
-   By default, an implicit `private import plain;' occurs before
-translating a file and before the first command given in interactive
-mode.  This also applies when translating files for module definitions
-(except when translating `plain', of course).  This means that the
-types and functions defined in `plain' are accessible in almost all
-`Asymptote' code. Use the `-noautoplain' command-line option to disable
-this feature.
-
-
-File: asymptote.info,  Node: simplex,  Next: math,  Prev: plain,  Up: Base modules
-
-8.2 `simplex'
-=============
-
-This package solves the two-variable linear programming problem using
-the simplex method. It is used by the module `plain' for automatic
-sizing of pictures.
-
-
-File: asymptote.info,  Node: math,  Next: interpolate,  Prev: simplex,  Up: Base modules
-
-8.3 `math'
-==========
-
-This package extends `Asymptote''s mathematical capabilities with
-useful functions such as
-
-`void drawline(picture pic=currentpicture, pair P, pair Q, pen p=currentpen);'
-     draw the visible portion of the (infinite) line going through `P'
-     and `Q', without altering the size of picture `pic', using pen `p'.
-
-`real intersect(triple P, triple Q, triple n, triple Z);'
-     returns the intersection time of the extension of the line segment
-     `PQ' with the plane perpendicular to `n' and passing through `Z'.
-
-`triple intersectionpoint(triple n0, triple P0, triple n1, triple P1);'
-     Return any point on the intersection of the two planes with normals
-     `n0' and `n1' passing through points `P0' and `P1', respectively.
-     If the planes are parallel, return `(infinity,infinity,infinity)'.
-
-`pair[] quarticroots(real a, real b, real c, real d, real e);'
-     returns the four complex roots of the quartic equation
-     ax^4+bx^3+cx^2+dx+e=0.
-
-`pair[][] fft(pair[][] a, int sign=1)'
-     returns the two-dimensional Fourier transform of a using the given
-     `sign'.
-
-`real time(path g, real x, int n=0)'
-     returns the `n'th intersection time of path `g' with the vertical
-     line through x.
-
-`real time(path g, explicit pair z, int n=0)'
-     returns the `n'th intersection time of path `g' with the horizontal
-     line through `(0,z.y)'.
-
-`real value(path g, real x, int n=0)'
-     returns the `n'th `y' value of `g' at `x'.
-
-`real value(path g, real x, int n=0)'
-     returns the `n'th `x' value of `g' at `y=z.y'.
-
-`real slope(path g, real x, int n=0)'
-     returns the `n'th slope of `g' at `x'.
-
-`real slope(path g, explicit pair z, int n=0)'
-     returns the `n'th slope of `g' at `y=z.y'.
-
-     int[][] segment(bool[] b) returns the indices of consecutive
-     true-element segments of bool[] `b'.
-
-`real[] partialsum(real[] a)'
-     returns the partial sums of a real array `a'.
-
-`real[] partialsum(real[] a, real[] dx)'
-     returns the partial `dx'-weighted sums of a real array `a'.
-
-`bool increasing(real[] a, bool strict=false)'
-     returns, if `strict=false', whether `i > j' implies `a[i] >=
-     a[j]', or if `strict=true', whether `i > j' implies implies `a[i]
-     > a[j]'.
-
-`int unique(real[] a, real x)'
-     if the sorted array `a' does not contain `x', insert it
-     sequentially, returning the index of `x' in the resulting array.
-
-`bool lexorder(pair a, pair b)'
-     returns the strict lexicographical partial order of `a' and `b'.
-
-`bool lexorder(triple a, triple b)'
-     returns the strict lexicographical partial order of `a' and `b'.
-
-
-File: asymptote.info,  Node: interpolate,  Next: geometry,  Prev: math,  Up: Base modules
-
-8.4 `interpolate'
-=================
-
-This module implements Lagrange, Hermite, and standard cubic spline
-interpolation in `Asymptote', as illustrated in the example
-`interpolate1.asy'.
-
-
-File: asymptote.info,  Node: geometry,  Next: trembling,  Prev: interpolate,  Up: Base modules
-
-8.5 `geometry'
-==============
-
-This module, written by Philippe Ivaldi, provides an extensive set of
-geometry routines, including `perpendicular' symbols and a `triangle'
-structure. Link to the documentation for the `geometry' module are
-posted here: `http://asymptote.sourceforge.net/links.html', including
-an extensive set of examples,
-`http://www.piprime.fr/files/asymptote/geometry/', and an index:
-
-     `http://www.piprime.fr/files/asymptote/geometry/modules/geometry.asy.index.type.html'
-
-
-File: asymptote.info,  Node: trembling,  Next: stats,  Prev: geometry,  Up: Base modules
-
-8.6 `trembling'
-===============
-
-This module, written by Philippe Ivaldi and illustrated in the example
-`floatingdisk.asy', allows one to draw wavy lines, as if drawn by hand.
-
-
-File: asymptote.info,  Node: stats,  Next: patterns,  Prev: trembling,  Up: Base modules
-
-8.7 `stats'
-===========
-
-This package implements a Gaussian random number generator and a
-collection of statistics routines, including `histogram' and
-`leastsquares'.
-
-
-File: asymptote.info,  Node: patterns,  Next: markers,  Prev: stats,  Up: Base modules
-
-8.8 `patterns'
-==============
-
-This package implements `Postscript' tiling patterns and includes
-several convenient pattern generation routines.
-
-
-File: asymptote.info,  Node: markers,  Next: tree,  Prev: patterns,  Up: Base modules
-
-8.9 `markers'
-=============
-
-This package implements specialized routines for marking paths and
-angles.  The principal mark routine provided by this package is
-markroutine markinterval(int n=1, frame f, bool rotated=false);
- which centers `n' copies of frame `f' within uniformly space intervals
-in arclength along the path, optionally rotated by the angle of the
-local tangent.
-
-   The `marker' (*note marker::) routine can be used to construct new
-markers from these predefined frames:
-
-frame stickframe(int n=1, real size=0, pair space=0, real angle=0,
-                 pair offset=0, pen p=currentpen);
- 
-frame circlebarframe(int n=1, real barsize=0,
-                     real radius=0,real angle=0,
-                     pair offset=0, pen p=currentpen,
-                     filltype filltype=NoFill, bool above=false);
- 
-frame crossframe(int n=3, real size=0, pair space=0,
-                 real angle=0, pair offset=0, pen p=currentpen);
- 
-frame tildeframe(int n=1, real size=0, pair space=0,
-                 real angle=0, pair offset=0, pen p=currentpen);
-
-   For convenience, this module also constructs the markers
-`StickIntervalMarker',  `CrossIntervalMarker',
-`CircleBarIntervalMarker', and `TildeIntervalMarker' from the above
-frames. The example `markers1.asy' illustrates the use of these markers:
-
-
-
-
-This package also provides a routine for marking an angle AOB: 
-void markangle(picture pic=currentpicture, Label L="",
-               int n=1, real radius=0, real space=0,
-               pair A, pair O, pair B, arrowbar arrow=None,
-               pen p=currentpen, margin margin=NoMargin,
-               marker marker=nomarker);
- as illustrated in the example `markers2.asy'.
-
-
-
-
-
-File: asymptote.info,  Node: tree,  Next: binarytree,  Prev: markers,  Up: Base modules
-
-8.10 `tree'
-===========
-
-This package implements an example of a dynamic binary search tree.
-
-
-File: asymptote.info,  Node: binarytree,  Next: drawtree,  Prev: tree,  Up: Base modules
-
-8.11 `binarytree'
-=================
-
-This module can be used to draw an arbitrary binary tree and includes an
-input routine for the special case of a binary search tree, as
-illustrated in the example `binarytreetest.asy':
-
-import binarytree;
-
-picture pic,pic2;
-
-binarytree bt=binarytree(1,2,4,nil,5,nil,nil,0,nil,nil,3,6,nil,nil,7);
-draw(pic,bt,condensed=false);
-
-binarytree st=searchtree(10,5,2,1,3,4,7,6,8,9,15,13,12,11,14,17,16,18,19);
-draw(pic2,st,blue,condensed=true);
-
-add(pic.fit(),(0,0),10N);
-add(pic2.fit(),(0,0),10S);
-
-
-
-
-File: asymptote.info,  Node: drawtree,  Next: syzygy,  Prev: binarytree,  Up: Base modules
-
-8.12 `drawtree'
-===============
-
-This is a simple tree drawing module used by the example `treetest.asy'.
-
-
-File: asymptote.info,  Node: syzygy,  Next: feynman,  Prev: drawtree,  Up: Base modules
-
-8.13 `syzygy'
-=============
-
-This module automates the drawing of braids, relations, and syzygies,
-along with the corresponding equations, as illustrated in the example
-`knots.asy'.
-
-
-File: asymptote.info,  Node: feynman,  Next: roundedpath,  Prev: syzygy,  Up: Base modules
-
-8.14 `feynman'
-==============
-
-This package, contributed by Martin Wiebusch, is useful for drawing
-Feynman diagrams, as illustrated by the examples `eetomumu.asy' and
-`fermi.asy'.
-
-
-File: asymptote.info,  Node: roundedpath,  Next: animation,  Prev: feynman,  Up: Base modules
-
-8.15 `roundedpath'
-==================
-
-This package, contributed by Stefan Knorr, is useful for rounding the
-sharp corners of paths, as illustrated in the example file
-`roundpath.asy'.
-
-
-File: asymptote.info,  Node: animation,  Next: embed,  Prev: roundedpath,  Up: Base modules
-
-8.16 `animation'
-================
-
-This module allows one to generate animations, as illustrated by the
-files `wheel.asy', `wavepacket.asy', and `cube.asy' in the `animations'
-subdirectory of the examples directory. These animations use the
-`ImageMagick' `convert' program to merge multiple images into a GIF or
-MPEG movie.
-
-   The related `animate' module, derived from the `animation' module,
-generates higher-quality portable clickable PDF movies, with optional
-controls. This requires installing the package
-
-     `http://www.ctan.org/tex-archive/macros/latex/contrib/animate/animate.sty'
-   (version 2007/11/30 or later) in a new directory `animate' in the
-local `LaTeX' directory (for example, in
-`/usr/local/share/texmf/tex/latex/animate'). On `UNIX' systems, one
-must then execute the command `texhash'.
-
-   The example `pdfmovie.asy' in the `animations' directory, along with
-the slide presentations `slidemovies.asy' and `intro.asy', illustrate
-the use of embedded PDF movies.  The examples `inlinemovie.tex' and
-`inlinemovie3.tex' show how to generate and embed PDF movies directly
-within a `LaTeX' file (*note LaTeX usage::).  The member function
-string pdf(fit fit=NoBox, real delay=animationdelay, string options="",
-           bool keep=settings.keep, bool multipage=true);
- of the `animate' structure accepts any of the `animate.sty' options,
-as described here:
-
-     `http://www.ctan.org/tex-archive/macros/latex/contrib/animate/doc/animate.pdf'
-
-
-File: asymptote.info,  Node: embed,  Next: slide,  Prev: animation,  Up: Base modules
-
-8.17 `embed'
-============
-
-This module provides an interface to the `LaTeX' package (included with
-`MikTeX')
-
-     `http://www.ctan.org/tex-archive/macros/latex/contrib/media9'
-   for embedding movies, sounds, and 3D objects into a PDF document.
-Version 0.13 (2012/09/12) of `media9' or later is required.
-
-   A more portable method for embedding movie files, which should work
-on any platform and does not require the `media9' package, is provided
-by using the `external' module instead of `embed'.
-
-   Examples of the above two interfaces is provided in the file
-`embeddedmovie.asy' and `externalmovie.asy' in the `animations'
-subdirectory of the examples directory. For a higher quality embedded
-movie generated directly by `Asymptote', use the `animate' module along
-with the `animate.sty' package to embed a portable PDF animation (*note
-animate::).
-
-   An example of embedding `U3D' code is provided in the file
-`embeddedu3d.asy'.
-
-
-File: asymptote.info,  Node: slide,  Next: MetaPost,  Prev: embed,  Up: Base modules
-
-8.18 `slide'
-============
-
-This package provides a simple yet high-quality facility for making
-presentation slides, including portable embedded PDF animations (see
-the file `slidemovies.asy'). A simple example is provided in the file
-`slidedemo.asy'.
-
-
-File: asymptote.info,  Node: MetaPost,  Next: unicode,  Prev: slide,  Up: Base modules
-
-8.19 `MetaPost'
-===============
-
-This package provides some useful routines to help `MetaPost' users
-migrate old `MetaPost' code to `Asymptote'. Further contributions here
-are welcome.
-
-   Unlike `MetaPost', `Asymptote' does not implicitly solve linear
-equations and therefore does not have the notion of a `whatever'
-unknown. The routine `extension' (*note extension::) provides a useful
-replacement for a common use of `whatever': finding the intersection
-point of the lines through `P', `Q' and `p', `q'. For less common
-occurrences of `whatever', one can use the built-in explicit linear
-equation solver `solve' instead.
-
-
-File: asymptote.info,  Node: unicode,  Next: latin1,  Prev: MetaPost,  Up: Base modules
-
-8.20 `unicode'
-==============
-
-Import this package at the beginning of the file to instruct `LaTeX' to
-accept `unicode' (UTF-8) standardized international characters.  To use
-Cyrillic fonts, you will need to change the font encoding:
-import unicode;
-texpreamble("\usepackage{mathtext}\usepackage[russian]{babel}");
-defaultpen(font("T2A","cmr","m","n"));
- Support for Chinese, Japanese, and Korean fonts is provided by the CJK
-package:
-
-     `http://www.ctan.org/tex-archive/languages/chinese/CJK/'
-   The following commands enable the CJK song family (within a label,
-you can also temporarily switch to another family, say kai, by
-prepending `"\CJKfamily{kai}"' to the label string):
-texpreamble("\usepackage{CJK}
-\AtBeginDocument{\begin{CJK*}{GBK}{song}}
-\AtEndDocument{\clearpage\end{CJK*}}");
-
-
-File: asymptote.info,  Node: latin1,  Next: babel,  Prev: unicode,  Up: Base modules
-
-8.21 `latin1'
-=============
-
-If you don't have `LaTeX' support for `unicode' installed, you can
-enable support for Western European languages (ISO 8859-1) by importing
-the module `latin1'. This module can be used as a template for
-providing support for other ISO 8859 alphabets.
-
-
-File: asymptote.info,  Node: babel,  Next: labelpath,  Prev: latin1,  Up: Base modules
-
-8.22 `babel'
-============
-
-This module implements the `LaTeX' `babel' package in `Asymptote'. For
-example:
-import babel;
-babel("german");
-
-
-File: asymptote.info,  Node: labelpath,  Next: labelpath3,  Prev: babel,  Up: Base modules
-
-8.23 `labelpath'
-================
-
-This module uses the `PSTricks' `pstextpath' macro to fit labels along
-a path (properly kerned, as illustrated in the example file
-`curvedlabel.asy'), using the command
-void labelpath(picture pic=currentpicture, Label L, path g,
-               string justify=Centered, pen p=currentpen);
- Here `justify' is one of `LeftJustified', `Centered', or
-`RightJustified'. The x component of a shift transform applied to the
-Label is interpreted as a shift along the curve, whereas the y
-component is interpreted as a shift away from the curve.  All other
-Label transforms are ignored. This package requires the `latex' tex
-engine and inherits the limitations of the `PSTricks' `\pstextpath'
-macro.
-
-
-File: asymptote.info,  Node: labelpath3,  Next: annotate,  Prev: labelpath,  Up: Base modules
-
-8.24 `labelpath3'
-=================
-
-This module, contributed by Jens Schwaiger, implements a 3D version of
-`labelpath' that does not require the `PSTricks' package.  An example
-is provided in `curvedlabel3.asy'.
-
-
-File: asymptote.info,  Node: annotate,  Next: CAD,  Prev: labelpath3,  Up: Base modules
-
-8.25 `annotate'
-===============
-
-This module supports PDF annotations for viewing with `Adobe Reader',
-via the function
-void annotate(picture pic=currentpicture, string title, string text,
-              pair position);
- Annotations are illustrated in the example file `annotation.asy'.
-Currently, annotations are only implemented for the `latex' (default)
-and `tex' TeX engines.
-
-
-File: asymptote.info,  Node: CAD,  Next: graph,  Prev: annotate,  Up: Base modules
-
-8.26 `CAD'
-==========
-
-This package, contributed by Mark Henning, provides basic pen
-definitions and measurement functions for simple 2D CAD drawings
-according to DIN 15. It is documented separately, in the file `CAD.pdf'.
-
-
-File: asymptote.info,  Node: graph,  Next: palette,  Prev: CAD,  Up: Base modules
-
-8.27 `graph'
-============
-
-This package implements two-dimensional linear and logarithmic graphs,
-including automatic scale and tick selection (with the ability to
-override manually). A graph is a `guide' (that can be drawn with the
-draw command, with an optional legend) constructed with one of the
-following routines:
-
-   * guide graph(picture pic=currentpicture, real f(real), real a, real b,
-                 int n=ngraph, real T(real)=identity,
-                 interpolate join=operator --);
-     guide[] graph(picture pic=currentpicture, real f(real), real a, real b,
-                  int n=ngraph, real T(real)=identity, bool3 cond(real),
-                  interpolate join=operator --);
-
-     Returns a graph using the scaling information for picture `pic'
-     (*note automatic scaling::) of the function `f' on the interval
-     [`T'(`a'),`T'(`b')], sampling at `n' points evenly spaced in
-     [`a',`b'], optionally restricted by the bool3 function `cond' on
-     [`a',`b']. If `cond' is:
-        * `true', the point is added to the existing guide;
-
-        * `default', the point is added to a new guide;
-
-        * `false', the point is omitted and a new guide is begun.
-     The points are connected using the interpolation specified by
-     `join':
-        * `operator --' (linear interpolation; the abbreviation
-          `Straight' is also accepted);
-
-        * `operator ..' (piecewise Bezier cubic spline interpolation;
-          the abbreviation `Spline' is also accepted);
-
-        * `Hermite' (standard cubic spline interpolation using boundary
-          condition `notaknot', `natural',  `periodic', `clamped(real
-          slopea, real slopeb)'), or `monotonic'.  The abbreviation
-          `Hermite' is equivalent to `Hermite(notaknot)' for
-          nonperiodic data and `Hermite(periodic)' for periodic data).
-
-
-   * guide graph(picture pic=currentpicture, real x(real), real y(real),
-                 real a, real b, int n=ngraph, real T(real)=identity,
-                 interpolate join=operator --);
-     guide[] graph(picture pic=currentpicture, real x(real), real y(real),
-                   real a, real b, int n=ngraph, real T(real)=identity,
-                   bool3 cond(real), interpolate join=operator --);
-
-     Returns a graph using the scaling information for picture `pic' of
-     the parametrized function (`x'(t),`y'(t)) for t in the interval
-     [`T'(`a'),`T'(`b')], sampling at `n' points evenly spaced in
-     [`a',`b'], optionally restricted by the bool3 function `cond' on
-     [`a',`b'], using the given interpolation type.
-
-   * guide graph(picture pic=currentpicture, pair z(real), real a, real b,
-                 int n=ngraph, real T(real)=identity,
-                 interpolate join=operator --);
-     guide[] graph(picture pic=currentpicture, pair z(real), real a, real b,
-                   int n=ngraph, real T(real)=identity, bool3 cond(real),
-                   interpolate join=operator --);
-
-     Returns a graph using the scaling information for picture `pic' of
-     the parametrized function `z'(t) for t in the interval
-     [`T'(`a'),`T'(`b')], sampling at `n' points evenly spaced in
-     [`a',`b'], optionally restricted by the bool3 function `cond' on
-     [`a',`b'], using the given interpolation type.
-
-   * guide graph(picture pic=currentpicture, pair[] z,
-                 interpolate join=operator --);
-     guide[] graph(picture pic=currentpicture, pair[] z, bool3[] cond,
-                   interpolate join=operator --);
-
-     Returns a graph using the scaling information for picture `pic' of
-     the elements of the array `z', optionally restricted to those
-     indices for which the elements of the boolean array `cond' are
-     `true', using the given interpolation type.
-
-   * guide graph(picture pic=currentpicture, real[] x, real[] y,
-                 interpolate join=operator --);
-     guide[] graph(picture pic=currentpicture, real[] x, real[] y,
-                   bool3[] cond, interpolate join=operator --);
-
-     Returns a graph using the scaling information for picture `pic' of
-     the elements of the arrays (`x',`y'), optionally restricted to
-     those indices for which the elements of the boolean array `cond'
-     are `true', using the given interpolation type.
-
-   * guide polargraph(picture pic=currentpicture, real f(real), real a,
-                      real b, int n=ngraph, interpolate join=operator --);
-
-     Returns a polar-coordinate graph using the scaling information for
-     picture `pic' of the function `f' on the interval [`a',`b'],
-     sampling at `n' evenly spaced points, with the given interpolation
-     type.
-
-   * guide polargraph(picture pic=currentpicture, real[] r, real[] theta,
-                      interpolate join=operator--);
-      Returns a polar-coordinate graph using the scaling information for
-     picture `pic' of the elements of the arrays (`r',`theta'), using
-     the given interpolation type.
-
-
-
-
-   An axis can be drawn on a picture with one of the following commands:
-
-   * void xaxis(picture pic=currentpicture, Label L="", axis axis=YZero,
-                real xmin=-infinity, real xmax=infinity, pen p=currentpen,
-                ticks ticks=NoTicks, arrowbar arrow=None, bool above=false);
-
-     Draw an x axis on picture `pic' from x=`xmin' to x=`xmax' using
-     pen `p', optionally labelling it with Label `L'. The relative
-     label location along the axis (a real number from [0,1]) defaults
-     to 1 (*note Label::), so that the label is drawn at the end of the
-     axis. An infinite value of `xmin' or `xmax' specifies that the
-     corresponding axis limit will be automatically determined from the
-     picture limits.  The optional `arrow' argument takes the same
-     values as in the `draw' command (*note arrows::). The axis is
-     drawn before any existing objects in `pic' unless `above=true'.
-     The axis placement is determined by one of the following `axis'
-     types:
-
-    `YZero(bool extend=true)'
-          Request an x axis at y=0 (or y=1 on a logarithmic axis)
-          extending to the full dimensions of the picture, unless
-          `extend'=false.
-
-    `YEquals(real Y, bool extend=true)'
-          Request an x axis at y=`Y' extending to the full dimensions
-          of the picture, unless `extend'=false.
-
-    `Bottom(bool extend=false)'
-          Request a bottom axis.
-
-    `Top(bool extend=false)'
-          Request a top axis.
-
-    `BottomTop(bool extend=false)'
-          Request a bottom and top axis.
-
-
-     Custom axis types can be created by following the examples in
-     `graph.asy'.  One can easily override the default values for the
-     standard axis types: import graph;
-
-     YZero=new axis(bool extend=true) {
-       return new void(picture pic, axisT axis) {
-         real y=pic.scale.x.scale.logarithmic ? 1 : 0;
-         axis.value=I*pic.scale.y.T(y);
-         axis.position=1;
-         axis.side=right;
-         axis.align=2.5E;
-         axis.value2=Infinity;
-         axis.extend=extend;
-       };
-     };
-     YZero=YZero();
-
-     The default tick option is `NoTicks'.  The options `LeftTicks',
-     `RightTicks', or `Ticks' can be used to draw ticks on the left,
-     right, or both sides of the path, relative to the direction in
-     which the path is drawn.  These tick routines accept a number of
-     optional arguments: ticks LeftTicks(Label format="", ticklabel ticklabel=null,
-                     bool beginlabel=true, bool endlabel=true,
-                     int N=0, int n=0, real Step=0, real step=0,
-                     bool begin=true, bool end=true, tickmodifier modify=None,
-                     real Size=0, real size=0, bool extend=false,
-                     pen pTick=nullpen, pen ptick=nullpen);
-
-     If any of these parameters are omitted, reasonable defaults will
-     be chosen:
-    `Label format'
-          override the default tick label format (`defaultformat',
-          initially "$%.4g$"), rotation, pen, and alignment (for
-          example, `LeftSide', `Center', or `RightSide') relative to
-          the axis. To enable `LaTeX' math mode fonts, the format
-          string should begin and end with `$' *note format::. If the
-          format string is `trailingzero', trailing zeros will be added
-          to the tick labels; if the format string is `"%"', the tick
-          label will be suppressed;
-
-    `ticklabel'
-          is a function `string(real x)' returning the label (by
-          default, format(format.s,x)) for each major tick value `x';
-
-    `bool beginlabel'
-          include the first label;
-
-    `bool endlabel'
-          include the last label;
-
-    `int N'
-          when automatic scaling is enabled (the default; *note
-          automatic scaling::), divide a linear axis evenly into this
-          many intervals, separated by major ticks; for a logarithmic
-          axis, this is the number of decades between labelled ticks;
-
-    `int n'
-          divide each interval into this many subintervals, separated
-          by minor ticks;
-
-    `real Step'
-          the tick value spacing between major ticks (if `N'=`0');
-
-    `real step'
-          the tick value spacing between minor ticks (if `n'=`0');
-
-    `bool begin'
-          include the first major tick;
-
-    `bool end'
-          include the last major tick;
-
-    `tickmodifier modify;'
-          an optional function that takes and returns a `tickvalue'
-          structure having real[] members `major' and `minor'
-          consisting of the tick values (to allow modification of the
-          automatically generated tick values);
-
-    `real Size'
-          the size of the major ticks (in `PostScript' coordinates);
-
-    `real size'
-          the size of the minor ticks (in `PostScript' coordinates);
-
-    `bool extend;'
-          extend the ticks between two axes (useful for drawing a grid
-          on the graph);
-
-    `pen pTick'
-          an optional pen used to draw the major ticks;
-
-    `pen ptick'
-          an optional pen used to draw the minor ticks.
-
-
-     For convenience, the predefined tickmodifiers `OmitTick(... real[]
-     x)', `OmitTickInterval(real a, real b)', and
-     `OmitTickIntervals(real[] a, real[] b)' can be used to remove
-     specific auto-generated ticks and their labels. The
-     `OmitFormat(string s=defaultformat ... real[] x)' ticklabel can be
-     used to remove specific tick labels but not the corresponding
-     ticks. The tickmodifier `NoZero' is an abbreviation for
-     `OmitTick(0)' and the ticklabel `NoZeroFormat' is an abbrevation
-     for `OmitFormat(0)'.
-
-     It is also possible to specify custom tick locations with
-     `LeftTicks', `RightTicks', and `Ticks' by passing explicit real
-     arrays `Ticks' and (optionally) `ticks' containing the locations
-     of the major and minor ticks, respectively: ticks LeftTicks(Label format="", ticklabel ticklabel=null,
-                     bool beginlabel=true, bool endlabel=true,
-                     real[] Ticks, real[] ticks=new real[],
-                     real Size=0, real size=0, bool extend=false,
-                     pen pTick=nullpen, pen ptick=nullpen)
-
-   * void yaxis(picture pic=currentpicture, Label L="", axis axis=XZero,
-                real ymin=-infinity, real ymax=infinity, pen p=currentpen,
-                ticks ticks=NoTicks, arrowbar arrow=None, bool above=false,
-                bool autorotate=true);
-
-     Draw a y axis on picture `pic' from y=`ymin' to y=`ymax' using pen
-     `p', optionally labelling it with a Label `L' that is autorotated
-     unless `autorotate=false'.  The relative location of the label (a
-     real number from [0,1]) defaults to 1 (*note Label::). An infinite
-     value of `ymin' or `ymax' specifies that the corresponding axis
-     limit will be automatically determined from the picture limits.
-     The optional `arrow' argument takes the same values as in the
-     `draw' command (*note arrows::). The axis is drawn before any
-     existing objects in `pic' unless `above=true'.  The tick type is
-     specified by `ticks' and the axis placement is determined by one
-     of the following `axis' types:
-
-    `XZero(bool extend=true)'
-          Request a y axis at x=0 (or x=1 on a logarithmic axis)
-          extending to the full dimensions of the picture, unless
-          `extend'=false.
-
-    `XEquals(real X, bool extend=true)'
-          Request a y axis at x=`X' extending to the full dimensions of
-          the picture, unless `extend'=false.
-
-    `Left(bool extend=false)'
-          Request a left axis.
-
-    `Right(bool extend=false)'
-          Request a right axis.
-
-    `LeftRight(bool extend=false)'
-          Request a left and right axis.
-
-
-   * For convenience, the functions void xequals(picture pic=currentpicture, Label L="", real x,
-                  bool extend=false, real ymin=-infinity, real ymax=infinity,
-                  pen p=currentpen, ticks ticks=NoTicks, bool above=true,
-                  arrowbar arrow=None);
-      and void yequals(picture pic=currentpicture, Label L="", real y,
-                  bool extend=false, real xmin=-infinity, real xmax=infinity,
-                  pen p=currentpen, ticks ticks=NoTicks, bool above=true,
-                  arrowbar arrow=None);
-      can be respectively used to call `yaxis' and `xaxis' with the
-     appropriate axis types `XEquals(x,extend)' and
-     `YEquals(y,extend)'. This is the recommended way of drawing
-     vertical or horizontal lines and axes at arbitrary locations.
-
-   * void axes(picture pic=currentpicture, Label xlabel="", Label ylabel="",
-               bool extend=true,
-               pair min=(-infinity,-infinity), pair max=(infinity,infinity),
-               pen p=currentpen, arrowbar arrow=None, bool above=false);
-      This convenience routine draws both x and y axes on picture `pic'
-     from `min' to `max', with optional labels `xlabel' and `ylabel'
-     and any arrows specified by `arrow'. The axes are drawn on top of
-     existing objects in `pic' only if `above=true'.
-
-   * void axis(picture pic=currentpicture, Label L="", path g,
-               pen p=currentpen, ticks ticks, ticklocate locate,
-               arrowbar arrow=None, int[] divisor=new int[],
-               bool above=false, bool opposite=false);
-
-     This routine can be used to draw on picture `pic' a general axis
-     based on an arbitrary path `g', using pen `p'.  One can optionally
-     label the axis with Label `L' and add an arrow `arrow'. The tick
-     type is given by `ticks'.  The optional integer array `divisor'
-     specifies what tick divisors to try in the attempt to produce
-     uncrowded tick labels. A `true' value for the flag `opposite'
-     identifies an unlabelled secondary axis (typically drawn opposite
-     a primary axis). The axis is drawn before any existing objects in
-     `pic' unless `above=true'.  The tick locator `ticklocate' is
-     constructed by the routine ticklocate ticklocate(real a, real b, autoscaleT S=defaultS,
-                           real tickmin=-infinity, real tickmax=infinity,
-                           real time(real)=null, pair dir(real)=zero);
-      where `a' and `b' specify the respective tick values at
-     `point(g,0)' and `point(g,length(g))', `S' specifies the
-     autoscaling transformation, the function `real time(real v)'
-     returns the time corresponding to the value `v', and `pair
-     dir(real t)' returns the absolute tick direction as a function of
-     `t' (zero means draw the tick perpendicular to the axis).
-
-   * These routines are useful for manually putting ticks and labels on
-     axes (if the variable `Label' is given as the `Label' argument,
-     the `format' argument will be used to format a string based on the
-     tick location): void xtick(picture pic=currentpicture, Label L="", explicit pair z,
-                pair dir=N, string format="",
-                real size=Ticksize, pen p=currentpen);
-     void xtick(picture pic=currentpicture, Label L="", real x,
-                pair dir=N, string format="",
-                real size=Ticksize, pen p=currentpen);
-     void ytick(picture pic=currentpicture, Label L="", explicit pair z,
-                pair dir=E, string format="",
-                real size=Ticksize, pen p=currentpen);
-     void ytick(picture pic=currentpicture, Label L="", real y,
-                pair dir=E, string format="",
-                real size=Ticksize, pen p=currentpen);
-     void tick(picture pic=currentpicture, pair z,
-               pair dir, real size=Ticksize, pen p=currentpen);
-     void labelx(picture pic=currentpicture, Label L="", explicit pair z,
-                 align align=S, string format="", pen p=currentpen);
-     void labelx(picture pic=currentpicture, Label L="", real x,
-                 align align=S, string format="", pen p=currentpen);
-     void labelx(picture pic=currentpicture, Label L,
-                 string format="", explicit pen p=currentpen);
-     void labely(picture pic=currentpicture, Label L="", explicit pair z,
-                 align align=W, string format="", pen p=currentpen);
-     void labely(picture pic=currentpicture, Label L="", real y,
-                 align align=W, string format="", pen p=currentpen);
-     void labely(picture pic=currentpicture, Label L,
-                 string format="", explicit pen p=currentpen);
-
-   Here are some simple examples of two-dimensional graphs:
-
-  1. This example draws a textbook-style graph of y= exp(x), with the y
-     axis starting at y=0: import graph;
-     size(150,0);
-
-     real f(real x) {return exp(x);}
-     pair F(real x) {return (x,f(x));}
-
-     xaxis("$x$");
-     yaxis("$y$",0);
-
-     draw(graph(f,-4,2,operator ..),red);
-
-     labely(1,E);
-     label("$e^x$",F(1),SE);
-
-
-
-  2. The next example draws a scientific-style graph with a legend.
-     The position of the legend can be adjusted either explicitly or by
-     using the graphical user interface `xasy' (*note GUI::). If an
-     `UnFill(real xmargin=0, real ymargin=xmargin)' or `Fill(pen)'
-     option is specified to `add', the legend will obscure any
-     underlying objects. Here we illustrate how to clip the portion of
-     the picture covered by a label:
-
-     import graph;
-
-     size(400,200,IgnoreAspect);
-
-     real Sin(real t) {return sin(2pi*t);}
-     real Cos(real t) {return cos(2pi*t);}
-
-     draw(graph(Sin,0,1),red,"$\sin(2\pi x)$");
-     draw(graph(Cos,0,1),blue,"$\cos(2\pi x)$");
-
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$y$",LeftRight,RightTicks(trailingzero));
-
-     label("LABEL",point(0),UnFill(1mm));
-
-     add(legend(),point(E),20E,UnFill);
-
-
-
-     To specify a fixed size for the graph proper, use `attach': import graph;
-
-     size(250,200,IgnoreAspect);
-
-     real Sin(real t) {return sin(2pi*t);}
-     real Cos(real t) {return cos(2pi*t);}
-
-     draw(graph(Sin,0,1),red,"$\sin(2\pi x)$");
-     draw(graph(Cos,0,1),blue,"$\cos(2\pi x)$");
-
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$y$",LeftRight,RightTicks(trailingzero));
-
-     label("LABEL",point(0),UnFill(1mm));
-
-     attach(legend(),truepoint(E),20E,UnFill);
-      A legend can have multiple entries per line: import graph;
-     size(8cm,6cm,IgnoreAspect);
-
-     typedef real realfcn(real);
-     realfcn F(real p) {
-       return new real(real x) {return sin(p*x);};
-     };
-
-     for(int i=1; i < 5; ++i)
-       draw(graph(F(i*pi),0,1),Pen(i),
-            "$\sin("+(i == 1 ? "" : (string) i)+"\pi x)$");
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$y$",LeftRight,RightTicks(trailingzero));
-
-     attach(legend(2),(point(S).x,truepoint(S).y),10S,UnFill);
-
-
-
-  3. This example draws a graph of one array versus another (both of
-     the same size) using custom tick locations and a smaller font size
-     for the tick labels on the y axis.  import graph;
-
-     size(200,150,IgnoreAspect);
-
-     real[] x={0,1,2,3};
-     real[] y=x^2;
-
-     draw(graph(x,y),red);
-
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$y$",LeftRight,
-           RightTicks(Label(fontsize(8pt)),new real[]{0,4,9}));
-
-
-
-  4. This example shows how to graph columns of data read from a file.  import graph;
-
-     size(200,150,IgnoreAspect);
-
-     file in=input("filegraph.dat").line();
-     real[][] a=in.dimension(0,0);
-     a=transpose(a);
-
-     real[] x=a[0];
-     real[] y=a[1];
-
-     draw(graph(x,y),red);
-
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$y$",LeftRight,RightTicks);
-
-
-
-  5. The next example draws two graphs of an array of coordinate pairs,
-     using frame alignment and data markers. In the left-hand graph, the
-     markers, constructed with marker marker(path g, markroutine markroutine=marknodes,
-                   pen p=currentpen, filltype filltype=NoFill,
-                   bool above=true);
-      using the path `unitcircle' (*note filltype::), are drawn below
-     each node. Any frame can be converted to a marker, using marker marker(frame f, markroutine markroutine=marknodes,
-                   bool above=true);
-      In the right-hand graph, the unit n-sided regular polygon
-     `polygon(int n)' and the unit n-point cyclic cross `cross(int n,
-     bool round=true, real r=0)' (where `r' is an optional "inner"
-     radius) are used to build a custom marker frame.  Here
-     `markuniform(bool centered=false, int n, bool rotated=false)' adds
-     this frame at `n' uniformly spaced points along the arclength of
-     the path, optionally rotated by the angle of the local tangent to
-     the path (if centered is true, the frames will be centered within
-     `n' evenly spaced arclength intervals). Alternatively, one can use
-     markroutine `marknodes' to request that the marks be placed at each
-     Bezier node of the path, or markroutine `markuniform(pair z(real
-     t), real a, real b, int n)' to place marks at points `z(t)' for n
-     evenly spaced values of `t' in `[a,b]'.
-
-     These markers are predefined: marker[] Mark={
-       marker(scale(circlescale)*unitcircle),
-       marker(polygon(3)),marker(polygon(4)),
-       marker(polygon(5)),marker(invert*polygon(3)),
-       marker(cross(4)),marker(cross(6))
-     };
-
-     marker[] MarkFill={
-       marker(scale(circlescale)*unitcircle,Fill),marker(polygon(3),Fill),
-       marker(polygon(4),Fill),marker(polygon(5),Fill),
-       marker(invert*polygon(3),Fill)
-     };
-
-     The example also illustrates the `errorbar' routines:
-
-     void errorbars(picture pic=currentpicture, pair[] z, pair[] dp,
-                    pair[] dm={}, bool[] cond={}, pen p=currentpen,
-                    real size=0);
-
-     void errorbars(picture pic=currentpicture, real[] x, real[] y,
-                    real[] dpx, real[] dpy, real[] dmx={}, real[] dmy={},
-                    bool[] cond={}, pen p=currentpen, real size=0);
-
-     Here, the positive and negative extents of the error are given by
-     the absolute values of the elements of the pair array `dp' and the
-     optional pair array `dm'. If `dm' is not specified, the positive
-     and negative extents of the error are assumed to be equal.  import graph;
-
-     picture pic;
-     real xsize=200, ysize=140;
-     size(pic,xsize,ysize,IgnoreAspect);
-
-     pair[] f={(5,5),(50,20),(90,90)};
-     pair[] df={(0,0),(5,7),(0,5)};
-
-     errorbars(pic,f,df,red);
-     draw(pic,graph(pic,f),"legend",
-          marker(scale(0.8mm)*unitcircle,red,FillDraw(blue),above=false));
-
-     scale(pic,true);
-
-     xaxis(pic,"$x$",BottomTop,LeftTicks);
-     yaxis(pic,"$y$",LeftRight,RightTicks);
-     add(pic,legend(pic),point(pic,NW),20SE,UnFill);
-
-     picture pic2;
-     size(pic2,xsize,ysize,IgnoreAspect);
-
-     frame mark;
-     filldraw(mark,scale(0.8mm)*polygon(6),green,green);
-     draw(mark,scale(0.8mm)*cross(6),blue);
-
-     draw(pic2,graph(pic2,f),marker(mark,markuniform(5)));
-
-     scale(pic2,true);
-
-     xaxis(pic2,"$x$",BottomTop,LeftTicks);
-     yaxis(pic2,"$y$",LeftRight,RightTicks);
-
-     yequals(pic2,55.0,red+Dotted);
-     xequals(pic2,70.0,red+Dotted);
-
-     // Fit pic to W of origin:
-     add(pic.fit(),(0,0),W);
-
-     // Fit pic2 to E of (5mm,0):
-     add(pic2.fit(),(5mm,0),E);
-
-
-
-  6. A custom mark routine can be also be specified: import graph;
-
-     size(200,100,IgnoreAspect);
-
-     markroutine marks() {
-       return new void(picture pic=currentpicture, frame f, path g) {
-         path p=scale(1mm)*unitcircle;
-         for(int i=0; i <= length(g); ++i) {
-           pair z=point(g,i);
-           frame f;
-           if(i % 4 == 0) {
-             fill(f,p);
-             add(pic,f,z);
-           } else {
-             if(z.y > 50) {
-               pic.add(new void(frame F, transform t) {
-                   path q=shift(t*z)*p;
-                   unfill(F,q);
-                   draw(F,q);
-                 });
-             } else {
-               draw(f,p);
-               add(pic,f,z);
-             }
-           }
-         }
-       };
-     }
-
-     pair[] f={(5,5),(40,20),(55,51),(90,30)};
-
-     draw(graph(f),marker(marks()));
-
-     scale(true);
-
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$y$",LeftRight,RightTicks);
-
-
-
-  7. This example shows how to label an axis with arbitrary strings.  import graph;
-
-     size(400,150,IgnoreAspect);
-
-     real[] x=sequence(12);
-     real[] y=sin(2pi*x/12);
-
-     scale(false);
-
-     string[] month={"Jan","Feb","Mar","Apr","May","Jun",
-                     "Jul","Aug","Sep","Oct","Nov","Dec"};
-
-     draw(graph(x,y),red,MarkFill[0]);
-
-     xaxis(BottomTop,LeftTicks(new string(real x) {
-           return month[round(x % 12)];}));
-     yaxis("$y$",LeftRight,RightTicks(4));
-
-
-
-  8. The next example draws a graph of a parametrized curve.  The calls
-     to xlimits(picture pic=currentpicture, real min=-infinity,
-             real max=infinity, bool crop=NoCrop);
-      and the analogous function `ylimits' can be uncommented to set
-     the respective axes limits for picture `pic' to the specified
-     `min' and `max' values. Alternatively, the function void limits(picture pic=currentpicture, pair min, pair max, bool crop=NoCrop);
-      can be used to limit the axes to the box having opposite vertices
-     at the given pairs). Existing objects in picture `pic' will be
-     cropped to lie within the given limits if `crop'=`Crop'. The
-     function `crop(picture pic)' can be used to crop a graph to the
-     current graph limits.  import graph;
-
-     size(0,200);
-
-     real x(real t) {return cos(2pi*t);}
-     real y(real t) {return sin(2pi*t);}
-
-     draw(graph(x,y,0,1));
-
-     //limits((0,-1),(1,0),Crop);
-
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$y$",LeftRight,RightTicks(trailingzero));
-
-
-
-     The next example illustrates how one can extract a common axis
-     scaling factor.  import graph;
-
-     axiscoverage=0.9;
-     size(200,IgnoreAspect);
-
-     real[] x={-1e-11,1e-11};
-     real[] y={0,1e6};
-
-     real xscale=round(log10(max(x)));
-     real yscale=round(log10(max(y)))-1;
-
-     draw(graph(x*10^(-xscale),y*10^(-yscale)),red);
-
-     xaxis("$x/10^{"+(string) xscale+"}$",BottomTop,LeftTicks);
-     yaxis("$y/10^{"+(string) yscale+"}$",LeftRight,RightTicks(trailingzero));
-
-
-
-     Axis scaling can be requested and/or automatic selection of the
-     axis limits can be inhibited with one of these `scale' routines: void scale(picture pic=currentpicture, scaleT x, scaleT y);
-
-     void scale(picture pic=currentpicture, bool xautoscale=true,
-                bool yautoscale=xautoscale, bool zautoscale=yautoscale);
-
-     This sets the scalings for picture `pic'. The `graph' routines
-     accept an optional `picture' argument for determining the
-     appropriate scalings to use; if none is given, it uses those set
-     for `currentpicture'.
-
-     Two frequently used scaling routines `Linear' and `Log' are
-     predefined in `graph'.
-
-     All picture coordinates (including those in paths and those given
-     to the `label' and `limits' functions) are always treated as linear
-     (post-scaled) coordinates. Use pair Scale(picture pic=currentpicture, pair z);
-      to convert a graph coordinate into a scaled picture coordinate.
-
-     The x and y components can be individually scaled using the
-     analogous routines real ScaleX(picture pic=currentpicture, real x);
-     real ScaleY(picture pic=currentpicture, real y);
-
-     The predefined scaling routines can be given two optional boolean
-     arguments: `automin=false' and `automax=automin'. These default to
-     `false' but can be respectively set to `true' to enable automatic
-     selection of "nice" axis minimum and maximum values. The `Linear'
-     scaling can also take as optional final arguments a multiplicative
-     scaling factor and intercept (e.g. for a depth axis, `Linear(-1)'
-     requests axis reversal).
-
-     For example, to draw a log/log graph of a function, use
-     `scale(Log,Log)': import graph;
-
-     size(200,200,IgnoreAspect);
-
-     real f(real t) {return 1/t;}
-
-     scale(Log,Log);
-
-     draw(graph(f,0.1,10));
-
-     //limits((1,0.1),(10,0.5),Crop);
-
-     dot(Label("(3,5)",align=S),Scale((3,5)));
-
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$y$",LeftRight,RightTicks);
-
-
-
-     By extending the ticks, one can easily produce a logarithmic grid: import graph;
-     size(200,200,IgnoreAspect);
-
-     real f(real t) {return 1/t;}
-
-     scale(Log,Log);
-     draw(graph(f,0.1,10),red);
-     pen thin=linewidth(0.5*linewidth());
-     xaxis("$x$",BottomTop,LeftTicks(begin=false,end=false,extend=true,
-                                     ptick=thin));
-     yaxis("$y$",LeftRight,RightTicks(begin=false,end=false,extend=true,
-                                      ptick=thin));
-
-
-
-     One can also specify custom tick locations and formats for
-     logarithmic axes: import graph;
-
-     size(300,175,IgnoreAspect);
-     scale(Log,Log);
-     draw(graph(identity,5,20));
-     xlimits(5,20);
-     ylimits(1,100);
-     xaxis("$M/M_\odot$",BottomTop,LeftTicks(DefaultFormat,
-                                             new real[] {6,10,12,14,16,18}));
-     yaxis("$\nu_{\rm upp}$ [Hz]",LeftRight,RightTicks(DefaultFormat));
-
-
-
-     It is easy to draw logarithmic graphs with respect to other bases: import graph;
-     size(200,IgnoreAspect);
-
-     // Base-2 logarithmic scale on y-axis:
-
-     real log2(real x) {static real log2=log(2); return log(x)/log2;}
-     real pow2(real x) {return 2^x;}
-
-     scaleT yscale=scaleT(log2,pow2,logarithmic=true);
-     scale(Linear,yscale);
-
-     real f(real x) {return 1+x^2;}
-
-     draw(graph(f,-4,4));
-
-     yaxis("$y$",ymin=1,ymax=f(5),RightTicks(Label(Fill(white))),EndArrow);
-     xaxis("$x$",xmin=-5,xmax=5,LeftTicks,EndArrow);
-
-
-
-     Here is an example of "broken" linear x and logarithmic y axes
-     that omit the segments [3,8] and [100,1000], respectively.  In the
-     case of a logarithmic axis, the break endpoints are automatically
-     rounded to the nearest integral power of the base.  import graph;
-
-     size(200,150,IgnoreAspect);
-
-     // Break the x axis at 3; restart at 8:
-     real a=3, b=8;
-
-     // Break the y axis at 100; restart at 1000:
-     real c=100, d=1000;
-
-     scale(Broken(a,b),BrokenLog(c,d));
-
-     real[] x={1,2,4,6,10};
-     real[] y=x^4;
-
-     draw(graph(x,y),red,MarkFill[0]);
-
-     xaxis("$x$",BottomTop,LeftTicks(Break(a,b)));
-     yaxis("$y$",LeftRight,RightTicks(Break(c,d)));
-
-     label(rotate(90)*Break,(a,point(S).y));
-     label(rotate(90)*Break,(a,point(N).y));
-     label(Break,(point(W).x,ScaleY(c)));
-     label(Break,(point(E).x,ScaleY(c)));
-
-
-
-  9. `Asymptote' can draw secondary axes with the routines picture secondaryX(picture primary=currentpicture, void f(picture));
-     picture secondaryY(picture primary=currentpicture, void f(picture));
-
-     In this example, `secondaryY' is used to draw a secondary linear y
-     axis against a primary logarithmic y axis: import graph;
-     texpreamble("\def\Arg{\mathop {\rm Arg}\nolimits}");
-
-     size(10cm,5cm,IgnoreAspect);
-
-     real ampl(real x) {return 2.5/(1+x^2);}
-     real phas(real x) {return -atan(x)/pi;}
-
-     scale(Log,Log);
-     draw(graph(ampl,0.01,10));
-     ylimits(0.001,100);
-
-     xaxis("$\omega\tau_0$",BottomTop,LeftTicks);
-     yaxis("$|G(\omega\tau_0)|$",Left,RightTicks);
-
-     picture q=secondaryY(new void(picture pic) {
-         scale(pic,Log,Linear);
-         draw(pic,graph(pic,phas,0.01,10),red);
-         ylimits(pic,-1.0,1.5);
-         yaxis(pic,"$\Arg G/\pi$",Right,red,
-               LeftTicks("$% #.1f$",
-                         begin=false,end=false));
-         yequals(pic,1,Dotted);
-       });
-     label(q,"(1,0)",Scale(q,(1,0)),red);
-     add(q);
-
-
-
-     A secondary logarithmic y axis can be drawn like this: import graph;
-
-     size(9cm,6cm,IgnoreAspect);
-     string data="secondaryaxis.csv";
-
-     file in=input(data).line().csv();
-
-     string[] titlelabel=in;
-     string[] columnlabel=in;
-
-     real[][] a=in.dimension(0,0);
-     a=transpose(a);
-     real[] t=a[0], susceptible=a[1], infectious=a[2], dead=a[3], larvae=a[4];
-     real[] susceptibleM=a[5], exposed=a[6],infectiousM=a[7];
-
-     scale(true);
-
-     draw(graph(t,susceptible,t >= 10 & t <= 15));
-     draw(graph(t,dead,t >= 10 & t <= 15),dashed);
-
-     xaxis("Time ($\tau$)",BottomTop,LeftTicks);
-     yaxis(Left,RightTicks);
-
-     picture secondary=secondaryY(new void(picture pic) {
-         scale(pic,Linear(true),Log(true));
-         draw(pic,graph(pic,t,infectious,t >= 10 & t <= 15),red);
-         yaxis(pic,Right,red,LeftTicks(begin=false,end=false));
-       });
-
-     add(secondary);
-     label(shift(5mm*N)*"Proportion of crows",point(NW),E);
-
-
-
- 10. Here is a histogram example, which uses the `stats' module.  import graph;
-     import stats;
-
-     size(400,200,IgnoreAspect);
-
-     int n=10000;
-     real[] a=new real[n];
-     for(int i=0; i < n; ++i) a[i]=Gaussrand();
-
-     draw(graph(Gaussian,min(a),max(a)),blue);
-
-     // Optionally calculate "optimal" number of bins a la Shimazaki and Shinomoto.
-     int N=bins(a);
-
-     histogram(a,min(a),max(a),N,normalize=true,low=0,lightred,black,bars=false);
-
-     xaxis("$x$",BottomTop,LeftTicks);
-     yaxis("$dP/dx$",LeftRight,RightTicks(trailingzero));
-
-
-
- 11. Here is an example of reading column data in from a file and a
-     least-squares fit, using the `stats' module.  size(400,200,IgnoreAspect);
-
-     import graph;
-     import stats;
-
-     file fin=input("leastsquares.dat").line();
-
-     real[][] a=fin.dimension(0,0);
-     a=transpose(a);
-
-     real[] t=a[0], rho=a[1];
-
-     // Read in parameters from the keyboard:
-     //real first=getreal("first");
-     //real step=getreal("step");
-     //real last=getreal("last");
-
-     real first=100;
-     real step=50;
-     real last=700;
-
-     // Remove negative or zero values of rho:
-     t=rho > 0 ? t : null;
-     rho=rho > 0 ? rho : null;
-
-     scale(Log(true),Linear(true));
-
-     int n=step > 0 ? ceil((last-first)/step) : 0;
-
-     real[] T,xi,dxi;
-
-     for(int i=0; i <= n; ++i) {
-       real first=first+i*step;
-       real[] logrho=(t >= first & t <= last) ? log(rho) : null;
-       real[] logt=(t >= first & t <= last) ? -log(t) : null;
-
-       if(logt.length < 2) break;
-
-       // Fit to the line logt=L.m*logrho+L.b:
-       linefit L=leastsquares(logt,logrho);
-
-       T.push(first);
-       xi.push(L.m);
-       dxi.push(L.dm);
-     }
-
-     draw(graph(T,xi),blue);
-     errorbars(T,xi,dxi,red);
-
-     crop();
-
-     ylimits(0);
-
-     xaxis("$T$",BottomTop,LeftTicks);
-     yaxis("$\xi$",LeftRight,RightTicks);
-
-
-
- 12. Here is an example that illustrates the general `axis' routine.  import graph;
-     size(0,100);
-
-     path g=ellipse((0,0),1,2);
-
-     scale(true);
-
-     axis(Label("C",align=10W),g,LeftTicks(endlabel=false,8,end=false),
-          ticklocate(0,360,new real(real v) {
-              path h=(0,0)--max(abs(max(g)),abs(min(g)))*dir(v);
-              return intersect(g,h)[0];}));
-
-
-
- 13. To draw a vector field of `n' arrows evenly spaced along the
-     arclength of a path, use the routine picture vectorfield(path vector(real), path g, int n, bool truesize=false,
-                         pen p=currentpen, arrowbar arrow=Arrow);
-      as illustrated in this simple example of a flow field: import graph;
-     defaultpen(1.0);
-
-     size(0,150,IgnoreAspect);
-
-     real arrowsize=4mm;
-     real arrowlength=2arrowsize;
-
-     typedef path vector(real);
-
-     // Return a vector interpolated linearly between a and b.
-     vector vector(pair a, pair b) {
-       return new path(real x) {
-         return (0,0)--arrowlength*interp(a,b,x);
-       };
-     }
-
-     real f(real x) {return 1/x;}
-
-     real epsilon=0.5;
-     path g=graph(f,epsilon,1/epsilon);
-
-     int n=3;
-     draw(g);
-     xaxis("$x$");
-     yaxis("$y$");
-
-     add(vectorfield(vector(W,W),g,n,true));
-     add(vectorfield(vector(NE,NW),(0,0)--(point(E).x,0),n,true));
-     add(vectorfield(vector(NE,NE),(0,0)--(0,point(N).y),n,true));
-
-
-
- 14. To draw a vector field of `nx'\times`ny' arrows in `box(a,b)', use
-     the routine picture vectorfield(path vector(pair), pair a, pair b,
-                         int nx=nmesh, int ny=nx, bool truesize=false,
-                         real maxlength=truesize ? 0 : maxlength(a,b,nx,ny),
-                         bool cond(pair z)=null, pen p=currentpen,
-                         arrowbar arrow=Arrow, margin margin=PenMargin)
-      as illustrated in this example: import graph;
-     size(100);
-
-     pair a=(0,0);
-     pair b=(2pi,2pi);
-
-     path vector(pair z) {return (0,0)--(sin(z.x),cos(z.y));}
-
-     add(vectorfield(vector,a,b));
-
-
-
- 15. The following scientific graphs, which illustrate many features of
-     `Asymptote''s graphics routines, were generated from the examples
-     `diatom.asy' and `westnile.asy', using the comma-separated data in
-     `diatom.csv' and `westnile.csv'.
-
-
-
-File: asymptote.info,  Node: palette,  Next: three,  Prev: graph,  Up: Base modules
-
-8.28 `palette'
-==============
-
-`Asymptote' can also generate color density images and palettes. The
-following palettes are predefined in `palette.asy':
-
-`pen[] Grayscale(int NColors=256)'
-     a grayscale palette;
-
-`pen[] Rainbow(int NColors=32766)'
-     a rainbow spectrum;
-
-`pen[] BWRainbow(int NColors=32761)'
-     a rainbow spectrum tapering off to black/white at the ends;
-
-`pen[] BWRainbow2(int NColors=32761)'
-     a double rainbow palette tapering off to black/white at the ends,
-     with a linearly scaled intensity.
-
-`pen[] Wheel(int NColors=32766)'
-     a full color wheel palette;
-
-`pen[] Gradient(int NColors=256 ... pen[] p)'
-     a palette varying linearly over the specified array of pens, using
-     NColors in each interpolation interval;
-
-
-   The function `cmyk(pen[] Palette)' may be used to convert any of
-these palettes to the CMYK colorspace.
-
-   A color density plot using palette `palette' can be generated from a
-function `f'(x,y) and added to a picture `pic': 
-bounds image(picture pic=currentpicture, real f(real, real),
-             range range=Full, pair initial, pair final,
-             int nx=ngraph, int ny=nx, pen[] palette, bool antialias=false)
- The function `f' will be sampled at `nx' and `ny' evenly spaced points
-over a rectangle defined by the points `initial' and `final',
-respecting the current graphical scaling of `pic'. The color space is
-scaled according to the z axis scaling (*note automatic scaling::). A
-bounds structure for the function values is returned:
-struct bounds {
-  real min;
-  real max;
-  // Possible tick intervals:
-  int[] divisor;
-}
- This information can be used for generating an optional palette bar.
-The palette color space corresponds to a range of values specified by
-the argument `range', which can be `Full', `Automatic', or an explicit
-range `Range(real min, real max)'.  Here `Full' specifies a range
-varying from the minimum to maximum values of the function over the
-sampling interval, while `Automatic' selects "nice" limits.  The
-example `imagecontour.asy' illustrates how level sets (contour lines)
-can be drawn on a color density plot (*note contour::).
-
-   A color density plot can also be generated from an explicit real[][]
-array `data': 
-bounds image(picture pic=currentpicture, real[][] f, range range=Full,
-             pair initial, pair final, pen[] palette,
-             bool transpose=(initial.x < final.x && initial.y < final.y),
-             bool copy=true, bool antialias=false);
- If the initial point is to the left and below the final point, by
-default the array indices are interpreted according to the Cartesian
-convention (first index: x, second index: y) rather than the usual
-matrix convention (first index: -y, second index: x).
-
-   To construct an image from an array of irregularly spaced points and
-an array of values `f' at these points, use one of the routines
-bounds image(picture pic=currentpicture, pair[] z, real[] f,
-             range range=Full, pen[] palette)
-bounds image(picture pic=currentpicture, real[] x, real[] y, real[] f,
-             range range=Full, pen[] palette)
-
-   An optionally labelled palette bar may be generated with the routine
-void palette(picture pic=currentpicture, Label L="", bounds bounds,
-             pair initial, pair final, axis axis=Right, pen[] palette,
-             pen p=currentpen, paletteticks ticks=PaletteTicks,
-             bool copy=true, bool antialias=false);
- The color space of `palette' is taken to be over bounds `bounds' with
-scaling given by the z scaling of `pic'.  The palette orientation is
-specified by `axis', which may be one of `Right', `Left', `Top', or
-`Bottom'.  The bar is drawn over the rectangle from `initial' to
-`final'.  The argument `paletteticks' is a special tick type (*note
-ticks::) that takes the following arguments:
-paletteticks PaletteTicks(Label format="", ticklabel ticklabel=null,
-                          bool beginlabel=true, bool endlabel=true,
-                          int N=0, int n=0, real Step=0, real step=0,
-                          pen pTick=nullpen, pen ptick=nullpen);
-
-   The image and palette bar can be fit to a frame and added and
-optionally aligned to a picture at the desired location:
-
-size(12cm,12cm);
-
-import graph;
-import palette;
-
-int n=256;
-real ninv=2pi/n;
-real[][] v=new real[n][n];
-
-for(int i=0; i < n; ++i)
-  for(int j=0; j < n; ++j)
-    v[i][j]=sin(i*ninv)*cos(j*ninv);
-
-pen[] Palette=BWRainbow();
-
-picture bar;
-
-bounds range=image(v,(0,0),(1,1),Palette);
-palette(bar,"$A$",range,(0,0),(0.5cm,8cm),Right,Palette,
-        PaletteTicks("$%+#.1f$"));
-add(bar.fit(),point(E),30E);
-
-
-
-Here is an example that uses logarithmic scaling of the function values:
-
-import graph;
-import palette;
-
-size(10cm,10cm,IgnoreAspect);
-
-real f(real x, real y) {
-  return 0.9*pow10(2*sin(x/5+2*y^0.25)) + 0.1*(1+cos(10*log(y)));
-}
-
-scale(Linear,Log,Log);
-
-pen[] Palette=BWRainbow();
-
-bounds range=image(f,Automatic,(0,1),(100,100),nx=200,Palette);
-
-xaxis("$x$",BottomTop,LeftTicks,above=true);
-yaxis("$y$",LeftRight,RightTicks,above=true);
-
-palette("$f(x,y)$",range,(0,200),(100,250),Top,Palette,
-        PaletteTicks(ptick=linewidth(0.5*linewidth())));
-
-
-
-One can also draw an image directly from a two-dimensional pen array or
-a function `pen f(int, int)':
-void image(picture pic=currentpicture, pen[][] data,
-           pair initial, pair final,
-           bool transpose=(initial.x < final.x && initial.y < final.y),
-           bool copy=true, bool antialias=false);
-void image(picture pic=currentpicture, pen f(int, int), int width, int height,
-           pair initial, pair final,
-           bool transpose=(initial.x < final.x && initial.y < final.y),
-           bool antialias=false);
- as illustrated in the following examples:
-
-size(200);
-
-import palette;
-
-int n=256;
-real ninv=2pi/n;
-pen[][] v=new pen[n][n];
-
-for(int i=0; i < n; ++i)
-  for(int j=0; j < n; ++j)
-    v[i][j]=rgb(0.5*(1+sin(i*ninv)),0.5*(1+cos(j*ninv)),0);
-
-image(v,(0,0),(1,1));
-
-
-
-import palette;
-
-size(200);
-
-real fracpart(real x) {return (x-floor(x));}
-
-pair pws(pair z) {
-  pair w=(z+exp(pi*I/5)/0.9)/(1+z/0.9*exp(-pi*I/5));
-  return exp(w)*(w^3-0.5*I);
-}
-
-int N=512;
-
-pair a=(-1,-1);
-pair b=(0.5,0.5);
-real dx=(b-a).x/N;
-real dy=(b-a).y/N;
-
-pen f(int u, int v) {
-  pair z=a+(u*dx,v*dy);
-  pair w=pws(z);
-  real phase=degrees(w,warn=false);
-  real modulus=w == 0 ? 0: fracpart(log(abs(w)));
-  return hsv(phase,1,sqrt(modulus));
-}
-
-image(f,N,N,(0,0),(300,300),antialias=true);
-
-
-
-For convenience, the module `palette' also defines functions that may
-be used to construct a pen array from a given function and palette:
-pen[] palette(real[] f, pen[] palette);
-pen[][] palette(real[][] f, pen[] palette);
-
-
-File: asymptote.info,  Node: three,  Next: obj,  Prev: palette,  Up: Base modules
-
-8.29 `three'
-============
-
-This module fully extends the notion of guides and paths in `Asymptote'
-to three dimensions. It introduces the new types guide3, path3, and
-surface.  Guides in three dimensions are specified with the same syntax
-as in two dimensions except that triples `(x,y,z)' are used in place of
-pairs `(x,y)' for the nodes and direction specifiers.  This
-generalization of John Hobby's spline algorithm is shape-invariant under
-three-dimensional rotation, scaling, and shifting, and reduces in the
-planar case to the two-dimensional algorithm used in `Asymptote',
-`MetaPost', and `MetaFont' [cf. J. C. Bowman, Proceedings in Applied
-Mathematics and Mechanics, 7:1, 2010021-2010022 (2007)].
-
-   For example, a unit circle in the XY plane may be filled and drawn
-like this:
-
-import three;
-
-size(100);
-
-path3 g=(1,0,0)..(0,1,0)..(-1,0,0)..(0,-1,0)..cycle;
-draw(g);
-draw(O--Z,red+dashed,Arrow3);
-draw(((-1,-1,0)--(1,-1,0)--(1,1,0)--(-1,1,0)--cycle));
-dot(g,red);
-
-
-and then distorted into a saddle:
-
-import three;
-
-size(100,0);
-path3 g=(1,0,0)..(0,1,1)..(-1,0,0)..(0,-1,1)..cycle;
-draw(g);
-draw(((-1,-1,0)--(1,-1,0)--(1,1,0)--(-1,1,0)--cycle));
-dot(g,red);
-
-
-Module `three' provides constructors for converting two-dimensional
-paths to three-dimensional ones, and vice-versa: 
-path3 path3(path p, triple plane(pair)=XYplane);
-path path(path3 p, pair P(triple)=xypart);
-
-   A Bezier surface, the natural two-dimensional generalization of
-Bezier curves, is defined in `three_surface.asy' as a structure
-containing an array of Bezier patches. Surfaces may drawn with one of
-the routines
-void draw(picture pic=currentpicture, surface s, int nu=1, int nv=1,
-          material surfacepen=currentpen, pen meshpen=nullpen,
-          light light=currentlight, light meshlight=light, string name="",
-          render render=defaultrender);
-void draw(picture pic=currentpicture, surface s, int nu=1, int nv=1,
-          material[] surfacepen, pen meshpen,
-          light light=currentlight, light meshlight=light, string name="",
-          render render=defaultrender);
-void draw(picture pic=currentpicture, surface s, int nu=1, int nv=1,
-          material[] surfacepen, pen[] meshpen=nullpens,
-          light light=currentlight, light meshlight=light, string name="",
-          render render=defaultrender);
-
- The parameters `nu' and `nv' specify the number of subdivisions for
-drawing optional mesh lines for each Bezier patch. The optional `name'
-parameter is used as a prefix for naming the surface patches in the PRC
-model tree.  Here material is a structure defined in `three_light.asy':
-struct material {
-  pen[] p; // diffusepen,ambientpen,emissivepen,specularpen
-  real opacity;
-  real shininess;
-...
-}
- These material properties are used to implement `OpenGL'-style
-lighting, based on the Phong-Blinn specular model. Sample Bezier
-surfaces are contained in the example files `BezierSurface.asy',
-`teapot.asy', and `parametricsurface.asy'. The structure `render'
-contains specialized rendering options documented at the beginning of
-module `three.asy'.
-
-   The examples `elevation.asy' and `sphericalharmonic.asy' illustrate
-how to draw a surface with patch-dependent colors.  The examples
-`vertexshading' and `smoothelevation' illustrate vertex-dependent
-colors, which is supported for both `Asymptote''s native `OpenGL'
-renderer and two-dimensional projections. Since the PRC output format
-does not currently support vertex shading of Bezier surfaces, PRC
-patches are shaded with the mean of the four vertex colors.
-
-   A surface can be constructed from a cyclic `path3' with the
-constructor
-surface surface(path3 external, triple[] internal=new triple[],
-                triple[] normals=new triple[], pen[] colors=new pen[],
-                bool3 planar=default);
- and then filled:
-draw(surface(path3(polygon(5))),red,nolight);
-draw(surface(unitcircle3),red,nolight);
-draw(surface(unitcircle3,new pen[] {red,green,blue,black}),nolight);
- The last example constructs a patch with vertex-specific colors.  A
-three-dimensional planar surface in the plane `plane' can be
-constructed from a two-dimensional cyclic path `g' with the constructor 
-surface surface(path p, triple plane(pair)=XYplane);
- and then filled:
-draw(surface((0,0)--E+2N--2E--E+N..0.2E..cycle),red);
- Planar Bezier surfaces patches are constructed using Orest Shardt's
-`bezulate' routine, which decomposes (possibly nonsimply connected)
-regions bounded (according to the `zerowinding' fill rule) by simple
-cyclic paths (intersecting only at the endpoints) into subregions
-bounded by cyclic paths of length `4' or less.
-
-   A more efficient routine also exists for drawing tessellations
-composed of many 3D triangles, with specified vertices, and optional
-normals or vertex colors: 
-void draw(picture pic=currentpicture, triple[] v, int[][] vi,
-          triple[] n={}, int[][] ni={}, material m=currentpen, pen[] p={},
-          int[][] pi={}, light light=currentlight);
- Here, the triple array `v' lists the distinct vertices, while the
-array `vi' lists integer arrays of length 3 containing the indices of
-`v' corresponding to the vertices of each triangle. Similarly, the
-arguments `n' and `ni' contain optional normal data and `p' and `pi'
-contain optional pen vertex data.  An example of this tessellation
-facility is given in `triangles.asy'.
-
-   Arbitrary thick three-dimensional curves and line caps (which the
-`OpenGL' standard does not require implementations to provide) are
-constructed with
-tube tube(path3 p, real width, render render=defaultrender);
- this returns a tube structure representing a tube of diameter `width'
-centered approximately on `g'. The tube structure consists of a surface
-`s' and the actual tube center, path3 `center'.  Drawing thick lines as
-tubes can be slow to render, especially with the `Adobe Reader'
-renderer. The setting `thick=false' can be used to disable this feature
-and force all lines to be drawn with `linewidth(0)' (one pixel wide,
-regardless of the resolution). By default, mesh and contour lines in
-three-dimensions are always drawn thin, unless an explicit line width
-is given in the pen parameter or the setting `thin' is set to `false'.
-The pens `thin()' and `thick()' defined in plain_pens.asy can also be
-used to override these defaults for specific draw commands.
-
-There are four choices for viewing 3D `Asymptote' output:
-  1. Use the native `Asymptote' adaptive `OpenGL'-based renderer (with
-     the command-line option `-V' and the default settings
-     `outformat=""' and `render=-1'). If you encounter warnings from
-     your graphics card driver, try specifying `-glOptions=-indirect'
-     on the command line. On `UNIX' systems with graphics support for
-     multisampling, the sample width can be controlled with the setting
-     `multisample'. An initial screen position can be specified with
-     the pair setting `position', where negative values are interpreted
-     as relative to the corresponding maximum screen dimension. The
-     default settings import settings;
-     leftbutton=new string[] {"rotate","zoom","shift","pan"};
-     middlebutton=new string[] {"menu"};
-     rightbutton=new string[] {"zoom/menu","rotateX","rotateY","rotateZ"};
-     wheelup=new string[] {"zoomin"};
-     wheeldown=new string[] {"zoomout"};
-      bind the mouse buttons as follows:
-        * Left: rotate
-
-        * Shift Left: zoom
-
-        * Ctrl Left: shift viewport
-
-        * Alt Left: pan
-
-        * Middle: menu (must be unmodified; ignores Shift, Ctrl, and
-          Alt)
-
-        * Wheel Up: zoom in
-
-        * Wheel Down: zoom out
-
-        * Right: zoom/menu (must be unmodified)
-
-        * Right double click: menu
-
-        * Shift Right: rotate about the X axis
-
-        * Ctrl Right: rotate about the Y axis
-
-        * Alt Right: rotate about the Z axis
-
-     The keyboard shortcuts are: 
-        * h: home
-
-        * f: toggle fitscreen
-
-        * x: spin about the X axis
-
-        * y: spin about the Y axis
-
-        * z: spin about the Z axis
-
-        * s: stop spinning
-
-        * m: rendering mode (solid/mesh/patch)
-
-        * e: export
-
-        * c: show camera parameters
-
-        * p: play animation
-
-        * r: reverse animation
-
-        * : step animation
-
-        * +: expand
-
-        * =: expand
-
-        * >: expand
-
-        * -: shrink
-
-        * _: shrink
-
-        * <: shrink
-
-        * q: exit
-
-        * Ctrl-q: exit
-
-  2. Render the scene to a specified rasterized format `outformat' at
-     the resolution of `n' pixels per `bp', as specified by the setting
-     `render=n'. A negative value of `n' is interpreted as `|2n|' for
-     EPS and PDF formats and `|n|' for other formats. The default value
-     of `render' is -1.  By default, the scene is internally rendered
-     at twice the specified resolution; this can be disabled by setting
-     `antialias=1'.  High resolution rendering is done by tiling the
-     image. If your graphics card allows it, the rendering can be made
-     more efficient by increasing the maximum tile size `maxtile' to
-     your screen dimensions (indicated by `maxtile=(0,0)'. If your
-     video card generates unwanted black stripes in the output, try
-     setting the horizontal and vertical components of `maxtiles' to
-     something less than your screen dimensions. The tile size is also
-     limited by the setting `maxviewport', which restricts the maximum
-     width and height of the viewport. On `UNIX' systems some graphics
-     drivers support batch mode (`-noV') rendering in an iconified
-     window; this can be enabled with the setting `iconify=true'.  Some
-     (broken) `UNIX' graphics drivers may require the command line
-     setting `-glOptions=-indirect', which requests (slower) indirect
-     rendering.
-
-  3. Embed the 3D PRC format in a PDF file and view the resulting PDF
-     file with version `9.0' or later of `Adobe Reader'.  In addition
-     to the default `settings.prc=true', this requires
-     `settings.outformat="pdf"', which can be specified by the command
-     line option `-f pdf', put in the `Asymptote' configuration file
-     (*note configuration file::), or specified in the script before
-     `three.asy' (or `graph3.asy') is imported.  The `media9' LaTeX
-     package is also required (*note embed::).  The example `pdb.asy'
-     illustrates how one can generate a list of predefined views (see
-     `100d.views').  A stationary preview image with a resolution of
-     `n' pixels per `bp' can be embedded with the setting `render=n';
-     this allows the file to be viewed with other `PDF' viewers.
-     Alternatively, the file `externalprc.tex' illustrates how the
-     resulting PRC and rendered image files can be extracted and
-     processed in a separate `LaTeX' file. However, see *note LaTeX
-     usage:: for an easier way to embed three-dimensional `Asymptote'
-     pictures within `LaTeX'.  The open-source PRC specification is
-     available from
-     `http://livedocs.adobe.com/acrobat_sdk/9/Acrobat9_HTMLHelp/API_References/PRCReference/PRC_Format_Specification/'.
-
-  4. Project the scene to a two-dimensional vector (EPS or PDF) format
-     with `render=0'. Only limited hidden surface removal facilities
-     are currently available with this approach (*note PostScript3D::).
-
-
-   Automatic picture sizing in three dimensions is accomplished with
-double deferred drawing. The maximal desired dimensions of the scene in
-each of the three dimensions can optionally be specified with the
-routine 
-void size3(picture pic=currentpicture, real x, real y=x, real z=y,
-          bool keepAspect=pic.keepAspect);
- The resulting simplex linear programming problem is then solved to
-produce a 3D version of a frame (actually implemented as a 3D picture).
-The result is then fit with another application of deferred drawing to
-the viewport dimensions corresponding to the usual two-dimensional
-picture `size' parameters. The global pair `viewportmargin' may be used
-to add horizontal and vertical margins to the viewport dimensions.
-Alternatively, a minimum `viewportsize' may be specified.  A 3D picture
-`pic' can be explicitly fit to a 3D frame by calling 
-frame pic.fit3(projection P=currentprojection);
- and then added to picture `dest' about `position' with 
-void add(picture dest=currentpicture, frame src, triple position=(0,0,0));
-
-   For convenience, the `three' module defines `O=(0,0,0)',
-`X=(1,0,0)', `Y=(0,1,0)', and `Z=(0,0,1)', along with a unitcircle in
-the XY plane:
-path3 unitcircle3=X..Y..-X..-Y..cycle;
-
-   A general (approximate) circle can be drawn perpendicular to the
-direction `normal' with the routine
-path3 circle(triple c, real r, triple normal=Z);
-
-   A circular arc centered at `c' with radius `r' from
-`c+r*dir(theta1,phi1)' to `c+r*dir(theta2,phi2)', drawing
-counterclockwise relative to the normal vector
-`cross(dir(theta1,phi1),dir(theta2,phi2))' if `theta2 > theta1' or if
-`theta2 == theta1' and `phi2 >= phi1', can be constructed with
-path3 arc(triple c, real r, real theta1, real phi1, real theta2, real phi2,
-          triple normal=O);
- The normal must be explicitly specified if `c' and the endpoints are
-colinear. If `r' < 0, the complementary arc of radius `|r|' is
-constructed.  For convenience, an arc centered at `c' from triple `v1'
-to `v2' (assuming `|v2-c|=|v1-c|') in the direction CCW
-(counter-clockwise) or CW (clockwise) may also be constructed with
-path3 arc(triple c, triple v1, triple v2, triple normal=O,
-          bool direction=CCW);
- When high accuracy is needed, the routines `Circle' and `Arc' defined
-in `graph3' may be used instead.  See *note GaussianSurface:: for an
-example of a three-dimensional circular arc.
-
-   The representation `O--O+u--O+u+v--O+v--cycle' of the plane passing
-through point `O' with normal `cross(u,v)' is returned by
-path3 plane(triple u, triple v, triple O=O);
- A three-dimensional box with opposite vertices at triples `v1' and
-`v2' may be drawn with the function 
-path3[] box(triple v1, triple v2);
- For example, a unit box is predefined as 
-path3[] unitbox=box(O,(1,1,1));
- `Asymptote' also provides optimized definitions for the
-three-dimensional paths `unitsquare3' and `unitcircle3', along with the
-surfaces `unitdisk', `unitplane', `unitcube', `unitcylinder',
-`unitcone', `unitsolidcone', `unitfrustum(real t1, real t2)',
-`unitsphere', and `unithemisphere'.
-
-These projections to two dimensions are predefined:
-`oblique'
-
-`oblique(real angle)'
-     The point `(x,y,z)' is projected to `(x-0.5z,y-0.5z)'.  If an
-     optional real argument is given, the negative z axis is drawn at
-     this angle in degrees.  The projection `obliqueZ' is a synonym for
-     `oblique'.
-
-`obliqueX'
-
-`obliqueX(real angle)'
-     The point `(x,y,z)' is projected to `(y-0.5x,z-0.5x)'.  If an
-     optional real argument is given, the negative x axis is drawn at
-     this angle in degrees.
-
-`obliqueY'
-
-`obliqueY(real angle)'
-     The point `(x,y,z)' is projected to `(x+0.5y,z+0.5y)'.  If an
-     optional real argument is given, the positive y axis is drawn at
-     this angle in degrees.
-
-`orthographic(triple camera, triple up=Z, triple target=O,
-     real zoom=1, pair viewportshift=0, bool showtarget=true,
-     bool center=false)'
-     This projects from three to two dimensions using the view as seen
-     at a point infinitely far away in the direction `unit(camera)',
-     orienting the camera so that, if possible, the vector `up' points
-     upwards. Parallel lines are projected to parallel lines. The
-     bounding volume is expanded to include `target' if
-     `showtarget=true'.  If `center=true', the target will be adjusted
-     to the center of the bounding volume.
-
-`orthographic(real x, real y, real z, triple up=Z, triple target=O,
-     real zoom=1, pair viewportshift=0, bool showtarget=true,
-     bool center=false)'
-     This is equivalent to orthographic((x,y,z),up,target,zoom,viewportshift,showtarget,center)
-
-     The routine triple camera(real alpha, real beta);
-      can be used to compute the camera position with the x axis below
-     the horizontal at angle `alpha', the y axis below the horizontal
-     at angle `beta', and the z axis up.
-
-`perspective(triple camera, triple up=Z, triple target=O,
-     real zoom=1, real angle=0, pair viewportshift=0,
-     bool showtarget=true, bool autoadjust=true,
-     bool center=autoadjust)'
-     This projects from three to two dimensions, taking account of
-     perspective, as seen from the location `camera' looking at
-     `target', orienting the camera so that, if possible, the vector
-     `up' points upwards.  If `render=0', projection of
-     three-dimensional cubic Bezier splines is implemented by
-     approximating a two-dimensional nonuniform rational B-spline
-     (NURBS) with a two-dimensional Bezier curve containing additional
-     nodes and control points. If `autoadjust=true', the camera will
-     automatically be adjusted to lie outside the bounding volume for
-     all possible interactive rotations about `target'.  If
-     `center=true', the target will be adjusted to the center of the
-     bounding volume.
-
-`perspective(real x, real y, real z, triple up=Z, triple target=O,
-     real zoom=1, real angle=0, pair viewportshift=0,
-     bool showtarget=true, bool autoadjust=true,
-     bool center=autoadjust)'
-     This is equivalent to perspective((x,y,z),up,target,zoom,angle,viewportshift,showtarget,
-                 autoadjust,center)
-
-The default projection, `currentprojection', is initially set to
-`perspective(5,4,2)'.
-
-   We also define standard orthographic views used in technical drawing:
-projection LeftView=orthographic(-X,showtarget=true);
-projection RightView=orthographic(X,showtarget=true);
-projection FrontView=orthographic(-Y,showtarget=true);
-projection BackView=orthographic(Y,showtarget=true);
-projection BottomView=orthographic(-Z,showtarget=true);
-projection TopView=orthographic(Z,showtarget=true);
- The function 
-void addViews(picture dest=currentpicture, picture src,
-              projection[][] views=SixViewsUS,
-              bool group=true, filltype filltype=NoFill);
- adds to picture `dest' an array of views of picture `src' using the
-layout projection[][] `views'. The default layout `SixViewsUS' aligns
-the projection `FrontView' below `TopView' and above `BottomView', to
-the right of `LeftView' and left of `RightView' and `BackView'.  The
-predefined layouts are: 
-projection[][] ThreeViewsUS={{TopView},
-                             {FrontView,RightView}};
-
-projection[][] SixViewsUS={{null,TopView},
-                           {LeftView,FrontView,RightView,BackView},
-                           {null,BottomView}};
-
-projection[][] ThreeViewsFR={{RightView,FrontView},
-                             {null,TopView}};
-
-projection[][] SixViewsFR={{null,BottomView},
-                           {RightView,FrontView,LeftView,BackView},
-                           {null,TopView}};
-
-projection[][] ThreeViews={{FrontView,TopView,RightView}};
-
-projection[][] SixViews={{FrontView,TopView,RightView},
-                         {BackView,BottomView,LeftView}};
-
-   A triple or path3 can be projected to a pair or path, with
-`project(triple, projection P=currentprojection)' or `project(path3,
-projection P=currentprojection)'.
-
-   It is occasionally useful to be able to invert a projection, sending
-a pair `z' onto the plane perpendicular to `normal' and passing through
-`point': 
-triple invert(pair z, triple normal, triple point,
-              projection P=currentprojection);
- A pair `z' on the projection plane can be inverted to a triple with
-the routine
-triple invert(pair z, projection P=currentprojection);
- A pair direction `dir' on the projection plane can be inverted to a
-triple direction relative to a point `v' with the routine
-triple invert(pair dir, triple v, projection P=currentprojection).
-
-   Three-dimensional objects may be transformed with one of the
-following built-in transform3 types (the identity transformation is
-`identity4'):
-
-`shift(triple v)'
-     translates by the triple `v';
-
-`xscale3(real x)'
-     scales by `x' in the x direction;
-
-`yscale3(real y)'
-     scales by `y' in the y direction;
-
-`zscale3(real z)'
-     scales by `z' in the z direction;
-
-`scale3(real s)'
-     scales by `s' in the x, y, and z directions;
-
-`scale(real x, real y, real z)'
-     scales by `x' in the x direction, by `y' in the y direction, and
-     by `z' in the z direction; 
-
-`rotate(real angle, triple v)'
-     rotates by `angle' in degrees about an axis `v' through the origin;
-
-`rotate(real angle, triple u, triple v)'
-     rotates by `angle' in degrees about the axis `u--v';
-
-`reflect(triple u, triple v, triple w)'
-     reflects about the plane through `u', `v', and `w'.  
-
-   When not multiplied on the left by a transform3, three-dimensional
-TeX Labels are drawn as Bezier surfaces directly on the projection
-plane: 
-void label(picture pic=currentpicture, Label L, triple position,
-           align align=NoAlign, pen p=currentpen,
-           light light=nolight, string name="",
-           render render=defaultrender, interaction interaction=
-           settings.autobillboard ? Billboard : Embedded)
- The optional `name' parameter is used as a prefix for naming the label
-patches in the PRC model tree.  The default interaction is `Billboard',
-which means that labels are rotated interactively so that they always
-face the camera.  The interaction `Embedded' means that the label
-interacts as a normal `3D' surface, as illustrated in the example
-`billboard.asy'.  Alternatively, a label can be transformed from the
-`XY' plane by an explicit transform3 or mapped to a specified
-two-dimensional plane with the predefined transform3 types `XY', `YZ',
-`ZX', `YX', `ZY', `ZX'. There are also modified versions of these
-transforms that take an optional argument `projection
-P=currentprojection' that rotate and/or flip the label so that it is
-more readable from the initial viewpoint.
-
-   A transform3 that projects in the direction `dir' onto the plane
-with normal `n' through point `O' is returned by
-transform3 planeproject(triple n, triple O=O, triple dir=n);
- One can use 
-triple normal(path3 p);
- to find the unit normal vector to a planar three-dimensional path `p'.
-As illustrated in the example `planeproject.asy', a transform3 that
-projects in the direction `dir' onto the plane defined by a planar path
-`p' is returned by
-transform3 planeproject(path3 p, triple dir=normal(p));
-
-   The functions 
-surface extrude(path p, triple axis=Z);
-surface extrude(Label L, triple axis=Z);
- return the surface obtained by extruding path `p' or Label `L' along
-`axis'.
-
-   Three-dimensional versions of the path functions `length', `size',
-`point', `dir', `accel', `radius', `precontrol', `postcontrol',
-`arclength', `arctime', `reverse', `subpath', `intersect',
-`intersections', `intersectionpoint', `intersectionpoints', `min',
-`max', `cyclic', and `straight' are also defined.
-
-   The routine 
-real[][] intersections(path3 p, surface s, real fuzz=-1);
- returns the intersection times of a path `p' with a surface `s' as a
-sorted array of real arrays of length 2, and 
-triple[] intersectionpoints(path3 p, surface s, real fuzz=-1);
- returns the corresponding intersection points.  Here, the computations
-are performed to the absolute error specified by `fuzz', or if `fuzz <
-0', to machine precision.
-
-   Here is an example showing all five guide3 connectors:
-
-import graph3;
-
-size(200);
-
-currentprojection=orthographic(500,-500,500);
-
-triple[] z=new triple[10];
-
-z[0]=(0,100,0); z[1]=(50,0,0); z[2]=(180,0,0);
-
-for(int n=3; n <= 9; ++n)
-  z[n]=z[n-3]+(200,0,0);
-
-path3 p=z[0]..z[1]---z[2]::{Y}z[3]
-&z[3]..z[4]--z[5]::{Y}z[6]
-&z[6]::z[7]---z[8]..{Y}z[9];
-
-draw(p,grey+linewidth(4mm),currentlight);
-
-xaxis3(Label(XY()*"$x$",align=-3Y),red,above=true);
-yaxis3(Label(XY()*"$y$",align=-3X),red,above=true);
-
-
-
-Three-dimensional versions of bars or arrows can be drawn with one of
-the specifiers `None', `Blank', `BeginBar3', `EndBar3' (or equivalently
-`Bar3'), `Bars3', `BeginArrow3', `MidArrow3', `EndArrow3' (or
-equivalently `Arrow3'), `Arrows3', `BeginArcArrow3', `EndArcArrow3' (or
-equivalently `ArcArrow3'), `MidArcArrow3', and `ArcArrows3'.
-Three-dimensional bars accept the optional arguments `(real size=0,
-triple dir=O)'. If `size=O', the default bar length is used; if
-`dir=O', the bar is drawn perpendicular to the path and the initial
-viewing direction. The predefined three-dimensional arrowhead styles
-are `DefaultHead3', `HookHead3', `TeXHead3'.  Versions of the
-two-dimensional arrowheads lifted to three-dimensional space and
-aligned according to the initial viewpoint (or an optionally specified
-`normal' vector) are also defined: `DefaultHead2(triple normal=O)',
-`HookHead2(triple normal=O)', `TeXHead2(triple normal=O)'. These are
-illustrated in the example `arrows3.asy'.
-
-   Module `three' also defines the three-dimensional margins
-`NoMargin3', `BeginMargin3', `EndMargin3', `Margin3', `Margins3',
-`BeginPenMargin2', `EndPenMargin2', `PenMargin2', `PenMargins2',
-`BeginPenMargin3', `EndPenMargin3', `PenMargin3', `PenMargins3',
-`BeginDotMargin3', `EndDotMargin3', `DotMargin3', `DotMargins3',
-`Margin3', and `TrueMargin3'.
-
-   The routine
-void pixel(picture pic=currentpicture, triple v, pen p=currentpen,
-           real width=1);
- can be used to draw on picture `pic' a pixel of width `width' at
-position `v' using pen `p'.
-
-   Further three-dimensional examples are provided in the files
-`near_earth.asy', `conicurv.asy', and (in the `animations'
-subdirectory) `cube.asy'.
-
-   Limited support for projected vector graphics (effectively
-three-dimensional nonrendered `PostScript') is available with the
-setting `render=0'. This currently only works for piecewise planar
-surfaces, such as those produced by the parametric `surface' routines
-in the `graph3' module. Surfaces produced by the `solids' package will
-also be properly rendered if the parameter `nslices' is sufficiently
-large.
-
-   In the module `bsp', hidden surface removal of planar pictures is
-implemented using a binary space partition and picture clipping.  A
-planar path is first converted to a structure `face' derived from
-`picture'. A `face' may be given to a two-dimensional drawing routine
-in place of any `picture' argument.  An array of such faces may then be
-drawn, removing hidden surfaces:
-void add(picture pic=currentpicture, face[] faces,
-         projection P=currentprojection);
- Labels may be projected to two dimensions, using projection `P', onto
-the plane passing through point `O' with normal `cross(u,v)' by
-multiplying it on the left by the transform
-transform transform(triple u, triple v, triple O=O,
-                    projection P=currentprojection);
-
-   Here is an example that shows how a binary space partition may be
-used to draw a two-dimensional vector graphics projection of three
-orthogonal intersecting planes:
-
-size(6cm,0);
-import bsp;
-
-real u=2.5;
-real v=1;
-
-currentprojection=oblique;
-
-path3 y=plane((2u,0,0),(0,2v,0),(-u,-v,0));
-path3 l=rotate(90,Z)*rotate(90,Y)*y;
-path3 g=rotate(90,X)*rotate(90,Y)*y;
-
-face[] faces;
-filldraw(faces.push(y),project(y),yellow);
-filldraw(faces.push(l),project(l),lightgrey);
-filldraw(faces.push(g),project(g),green);
-
-add(faces);
-
-
-
-
-File: asymptote.info,  Node: obj,  Next: graph3,  Prev: three,  Up: Base modules
-
-8.30 `obj'
-==========
-
-This module allows one to construct surfaces from simple obj files, as
-illustrated in the example files `galleon.asy' and `triceratops.asy'.
-
-
-File: asymptote.info,  Node: graph3,  Next: grid3,  Prev: obj,  Up: Base modules
-
-8.31 `graph3'
-=============
-
-This module implements three-dimensional versions of the functions in
-`graph.asy'.  To draw an x axis in three dimensions, use the routine
-void xaxis3(picture pic=currentpicture, Label L="", axis axis=YZZero,
-            real xmin=-infinity, real xmax=infinity, pen p=currentpen,
-            ticks3 ticks=NoTicks3, arrowbar3 arrow=None, bool above=false);
- Analogous routines `yaxis' and `zaxis' can be used to draw y and z
-axes in three dimensions.  There is also a routine for drawing all
-three axis:
-void axes3(picture pic=currentpicture,
-           Label xlabel="", Label ylabel="", Label zlabel="",
-           bool extend=false,
-           triple min=(-infinity,-infinity,-infinity),
-           triple max=(infinity,infinity,infinity),
-           pen p=currentpen, arrowbar3 arrow=None);
-
-The predefined three-dimensional axis types are
-axis YZEquals(real y, real z, triple align=O, bool extend=false);
-axis XZEquals(real x, real z, triple align=O, bool extend=false);
-axis XYEquals(real x, real y, triple align=O, bool extend=false);
-axis YZZero(triple align=O, bool extend=false);
-axis XZZero(triple align=O, bool extend=false);
-axis XYZero(triple align=O, bool extend=false);
-axis Bounds(int type=Both, int type2=Both, triple align=O, bool extend=false);
- The optional `align' parameter to these routines can be used to
-specify the default axis and tick label alignments. The `Bounds' axis
-accepts two type parameters, each of which must be one of `Min', `Max',
-or `Both'. These parameters specify which of the four possible
-three-dimensional bounding box edges should be drawn.
-
-   The three-dimensional tick options are `NoTicks3', `InTicks',
-`OutTicks', and `InOutTicks'. These specify the tick directions for the
-`Bounds' axis type; other axis types inherit the direction that would
-be used for the `Bounds(Min,Min)' axis.
-
-   Here is an example of a helix and bounding box axes with ticks and
-axis labels, using orthographic projection:
-
-import graph3;
-
-size(0,200);
-size3(200,IgnoreAspect);
-
-currentprojection=orthographic(4,6,3);
-
-real x(real t) {return cos(2pi*t);}
-real y(real t) {return sin(2pi*t);}
-real z(real t) {return t;}
-
-path3 p=graph(x,y,z,0,2.7,operator ..);
-
-draw(p,Arrow3);
-
-scale(true);
-
-xaxis3(XZ()*"$x$",Bounds,red,InTicks(Label,2,2));
-yaxis3(YZ()*"$y$",Bounds,red,InTicks(beginlabel=false,Label,2,2));
-zaxis3(XZ()*"$z$",Bounds,red,InTicks);
-
-
-
-The next example illustrates three-dimensional x, y, and z axes,
-without autoscaling of the axis limits: 
-
-import graph3;
-
-size(0,200);
-size3(200,IgnoreAspect);
-
-currentprojection=perspective(5,2,2);
-
-scale(Linear,Linear,Log);
-
-xaxis3("$x$",0,1,red,OutTicks(2,2));
-yaxis3("$y$",0,1,red,OutTicks(2,2));
-zaxis3("$z$",1,30,red,OutTicks(beginlabel=false));
-
-
-
-One can also place ticks along a general three-dimensional axis: 
-
-import graph3;
-
-size(0,100);
-
-path3 g=yscale3(2)*unitcircle3;
-currentprojection=perspective(10,10,10);
-
-axis(Label("C",position=0,align=15X),g,InTicks(endlabel=false,8,end=false),
-     ticklocate(0,360,new real(real v) {
-         path3 h=O--max(abs(max(g)),abs(min(g)))*dir(90,v);
-         return intersect(g,h)[0];},
-       new triple(real t) {return cross(dir(g,t),Z);}));
-
-
-
-Surface plots of matrices and functions over the region `box(a,b)' in
-the XY plane are also implemented:
-surface surface(real[][] f, pair a, pair b, bool[][] cond={});
-surface surface(real[][] f, pair a, pair b, splinetype xsplinetype,
-                splinetype ysplinetype=xsplinetype, bool[][] cond={});
-surface surface(real[][] f, real[] x, real[] y,
-                splinetype xsplinetype=null, splinetype ysplinetype=xsplinetype,
-                bool[][] cond={})
-surface surface(triple[][] f, bool[][] cond={});
-surface surface(real f(pair z), pair a, pair b, int nx=nmesh, int ny=nx,
-                bool cond(pair z)=null);
-surface surface(real f(pair z), pair a, pair b, int nx=nmesh, int ny=nx,
-                splinetype xsplinetype, splinetype ysplinetype=xsplinetype,
-                bool cond(pair z)=null);
-surface surface(triple f(pair z), real[] u, real[] v,
-                splinetype[] usplinetype, splinetype[] vsplinetype=Spline,
-                bool cond(pair z)=null);
-surface surface(triple f(pair z), pair a, pair b, int nu=nmesh, int nv=nu,
-                bool cond(pair z)=null);
-surface surface(triple f(pair z), pair a, pair b, int nu=nmesh, int nv=nu,
-                splinetype[] usplinetype, splinetype[] vsplinetype=Spline,
-                bool cond(pair z)=null);
- The final two versions draw parametric surfaces for a function f(u,v)
-over the parameter space `box(a,b)', as illustrated in the example
-`parametricsurface.asy'.  An optional splinetype `Spline' may be
-specified.  The boolean array or function `cond' can be used to control
-which surface mesh cells are actually drawn (by default all mesh cells
-over `box(a,b)' are drawn).  Surface lighting is illustrated in the
-example files `parametricsurface.asy' and `sinc.asy'.  Lighting can be
-disabled by setting `light=nolight', as in this example of a Gaussian
-surface:
-
-import graph3;
-
-size(200,0);
-
-currentprojection=perspective(10,8,4);
-
-real f(pair z) {return 0.5+exp(-abs(z)^2);}
-
-draw((-1,-1,0)--(1,-1,0)--(1,1,0)--(-1,1,0)--cycle);
-
-draw(arc(0.12Z,0.2,90,60,90,25),ArcArrow3);
-
-surface s=surface(f,(-1,-1),(1,1),nx=5,Spline);
-
-xaxis3(Label("$x$"),red,Arrow3);
-yaxis3(Label("$y$"),red,Arrow3);
-zaxis3(XYZero(extend=true),red,Arrow3);
-
-draw(s,lightgray,meshpen=black+thick(),nolight,render(merge=true));
-
-label("$O$",O,-Z+Y,red);
-
-
-A mesh can be drawn without surface filling by specifying `nullpen' for
-the surfacepen.
-
-   A vector field of `nu'\times`nv' arrows on a parametric surface `f'
-over `box(a,b)' can be drawn with the routine 
-picture vectorfield(path3 vector(pair v), triple f(pair z), pair a, pair b,
-                    int nu=nmesh, int nv=nu, bool truesize=false,
-                    real maxlength=truesize ? 0 : maxlength(f,a,b,nu,nv),
-                    bool cond(pair z)=null, pen p=currentpen,
-                    arrowbar3 arrow=Arrow3, margin3 margin=PenMargin3)
- as illustrated in the examples `vectorfield3.asy' and
-`vectorfieldsphere.asy'.
-
-
-File: asymptote.info,  Node: grid3,  Next: solids,  Prev: graph3,  Up: Base modules
-
-8.32 `grid3'
-============
-
-This module, contributed by Philippe Ivaldi, can be used for drawing 3D
-grids. Here is an example (further examples can be found in `grid3.asy'
-and at `http://www.piprime.fr/files/asymptote/grid3/'):
-
-import grid3;
-
-size(8cm,0,IgnoreAspect);
-currentprojection=orthographic(0.5,1,0.5);
-
-scale(Linear, Linear, Log);
-
-limits((-2,-2,1),(0,2,100));
-
-grid3(XYZgrid);
-
-xaxis3(Label("$x$",position=EndPoint,align=S),Bounds(Min,Min),
-       OutTicks());
-yaxis3(Label("$y$",position=EndPoint,align=S),Bounds(Min,Min),OutTicks());
-zaxis3(Label("$z$",position=EndPoint,align=(-1,0.5)),Bounds(Min,Min),
-       OutTicks(beginlabel=false));
-
-
-
-
-File: asymptote.info,  Node: solids,  Next: tube,  Prev: grid3,  Up: Base modules
-
-8.33 `solids'
-=============
-
-This solid geometry package defines a structure `revolution' that can
-be used to fill and draw surfaces of revolution. The following example
-uses it to display the outline of a circular cylinder of radius 1 with
-axis `O--1.5unit(Y+Z)' with perspective projection:
-
-import solids;
-
-size(0,100);
-
-revolution r=cylinder(O,1,1.5,Y+Z);
-draw(r,heavygreen);
-
-
-
-Further illustrations are provided in the example files `cylinder.asy',
-`cones.asy', `hyperboloid.asy', and `torus.asy'.
-
-   The structure `skeleton' contains the three-dimensional wireframe
-used to visualize a volume of revolution:
-struct skeleton {
-  struct curve {
-    path3[] front;
-    path3[] back;
-  }
-  // transverse skeleton (perpendicular to axis of revolution)
-  curve transverse;
-  // longitudinal skeleton (parallel to axis of revolution)
-  curve longitudinal;
-}
-
-
-File: asymptote.info,  Node: tube,  Next: flowchart,  Prev: solids,  Up: Base modules
-
-8.34 `tube'
-===========
-
-This package extends the `tube' surfaces constructed in
-`three_arrows.asy' to arbitrary cross sections, colors, and spine
-transformations. The routine
-surface tube(path3 g, coloredpath section,
-             transform T(real)=new transform(real t) {return identity();},
-             real corner=1, real relstep=0);
- draws a tube along `g' with cross section `section', after applying
-the transformation `T(t)' at `relpoint(g,t)'.  The parameter `corner'
-controls the number of elementary tubes at the angular points of `g'. A
-nonzero value of `relstep' specifies a fixed relative time step (in the
-sense of `relpoint(g,t)') to use in constructing elementary tubes along
-`g'.  The type `coloredpath' is a generalization of `path' to which a
-`path' can be cast: 
-struct coloredpath
-{
-  path p;
-  pen[] pens(real);
-  int colortype=coloredSegments;
-}
- Here `p' defines the cross section and the method `pens(real t)'
-returns an array of pens (interpreted as a cyclic array) used for
-shading the tube patches at `relpoint(g,t)'. If
-`colortype=coloredSegments', the tube patches are filled as if each
-segment of the section was colored with the pen returned by `pens(t)',
-whereas if `colortype=coloredNodes', the tube components are vertex
-shaded as if the nodes of the section were colored.
-
-   A `coloredpath' can be constructed with one of the routines:
-coloredpath coloredpath(path p, pen[] pens(real),
-                        int colortype=coloredSegments);
-coloredpath coloredpath(path p, pen[] pens=new pen[] {currentpen},
-                        int colortype=coloredSegments);
-coloredpath coloredpath(path p, pen pen(real));
- In the second case, the pens are independent of the relative time.  In
-the third case, the array of pens contains only one pen, which depends
-of the relative time.
-
-   The casting of `path' to `coloredpath' allows the use of a `path'
-instead of a `coloredpath'; in this case the shading behaviour is the
-default shading behavior for a surface.
-
-   An example of `tube' is provided in the file `trefoilknot.asy'.
-Further examples can be found at
-`http://www.piprime.fr/files/asymptote/tube/'.
-
-
-File: asymptote.info,  Node: flowchart,  Next: contour,  Prev: tube,  Up: Base modules
-
-8.35 `flowchart'
-================
-
-This package provides routines for drawing flowcharts. The primary
-structure is a `block', which represents a single block on the
-flowchart. The following eight functions return a position on the
-appropriate edge of the block, given picture transform `t':
-
-pair block.top(transform t=identity());
-pair block.left(transform t=identity());
-pair block.right(transform t=identity());
-pair block.bottom(transform t=identity());
-pair block.topleft(transform t=identity());
-pair block.topright(transform t=identity());
-pair block.bottomleft(transform t=identity());
-pair block.bottomright(transform t=identity());
- 
-
-To obtain an arbitrary position along the boundary of the block in user
-coordinates, use:
-pair block.position(real x, transform t=identity());
- 
-
-The center of the block in user coordinates is stored in `block.center'
-and the block size in `PostScript' coordinates is given by `block.size'.
-
-A frame containing the block is returned by
-frame block.draw(pen p=currentpen);
- 
-
-   The following block generation routines accept a Label, string, or
-frame for their object argument:
-
-"rectangular block with an optional header (and padding `dx' around header and body):"
-     block rectangle(object header, object body, pair center=(0,0),
-                     pen headerpen=mediumgray, pen bodypen=invisible,
-                     pen drawpen=currentpen,
-                     real dx=3, real minheaderwidth=minblockwidth,
-                     real minheaderheight=minblockwidth,
-                     real minbodywidth=minblockheight,
-                     real minbodyheight=minblockheight);
-     block rectangle(object body, pair center=(0,0),
-                     pen fillpen=invisible, pen drawpen=currentpen,
-                     real dx=3, real minwidth=minblockwidth,
-                     real minheight=minblockheight);
-
-"parallelogram block:"
-     block parallelogram(object body, pair center=(0,0),
-                         pen fillpen=invisible, pen drawpen=currentpen,
-                         real dx=3, real slope=2,
-                         real minwidth=minblockwidth,
-                         real minheight=minblockheight);
-
-"diamond-shaped block:"
-     block diamond(object body, pair center=(0,0),
-                   pen fillpen=invisible, pen drawpen=currentpen,
-                   real ds=5, real dw=1,
-                   real height=20, real minwidth=minblockwidth,
-                   real minheight=minblockheight);
-
-"circular block:"
-     block circle(object body, pair center=(0,0), pen fillpen=invisible,
-                  pen drawpen=currentpen, real dr=3,
-                  real mindiameter=mincirclediameter);
-
-"rectangular block with rounded corners:"
-     block roundrectangle(object body, pair center=(0,0),
-                          pen fillpen=invisible, pen drawpen=currentpen,
-                          real ds=5, real dw=0, real minwidth=minblockwidth,
-                          real minheight=minblockheight);
-
-"rectangular block with beveled edges:"
-     block bevel(object body, pair center=(0,0), pen fillpen=invisible,
-                 pen drawpen=currentpen, real dh=5, real dw=5,
-                 real minwidth=minblockwidth, real minheight=minblockheight);
-
-
-   To draw paths joining the pairs in `point' with right-angled lines,
-use the routine: 
-path path(pair point[] ... flowdir dir[]);
- The entries in `dir' identify whether successive segments between the
-pairs specified by `point' should be drawn in the `Horizontal' or
-`Vertical' direction.
-
-   Here is a simple flowchart example (see also the example
-`controlsystem.asy'):
-
-size(0,300);
-
-import flowchart;
-
-block block1=rectangle(Label("Example",magenta),
-		       pack(Label("Start:",heavygreen),"",Label("$A:=0$",blue),
-			    "$B:=1$"),(-0.5,3),palegreen,paleblue,red);
-block block2=diamond(Label("Choice?",blue),(0,2),palegreen,red);
-block block3=roundrectangle("Do something",(-1,1));
-block block4=bevel("Don't do something",(1,1));
-block block5=circle("End",(0,0));
-
-draw(block1);
-draw(block2);
-draw(block3);
-draw(block4);
-draw(block5);
-
-add(new void(picture pic, transform t) {
-    blockconnector operator --=blockconnector(pic,t);
-    //    draw(pic,block1.right(t)--block2.top(t));
-    block1--Right--Down--Arrow--block2;
-    block2--Label("Yes",0.5,NW)--Left--Down--Arrow--block3;
-    block2--Right--Label("No",0.5,NE)--Down--Arrow--block4;
-    block4--Down--Left--Arrow--block5;
-    block3--Down--Right--Arrow--block5;
-  });
-
-
-
-
-File: asymptote.info,  Node: contour,  Next: contour3,  Prev: flowchart,  Up: Base modules
-
-8.36 `contour'
-==============
-
-This package draws contour lines.  To construct contours corresponding
-to the values in a real array `c' for a function `f' on `box(a,b)', use
-the routine
-guide[][] contour(real f(real, real), pair a, pair b,
-                  real[] c, int nx=ngraph, int ny=nx,
-                  interpolate join=operator --, int subsample=1);
- The integers `nx' and `ny' define the resolution.  The default
-resolution, `ngraph x ngraph' (here `ngraph' defaults to `100') can be
-increased for greater accuracy.  The default interpolation operator is
-`operator --' (linear). Spline interpolation (`operator ..') may
-produce smoother contours but it can also lead to overshooting.  The
-`subsample' parameter indicates the number of interior points that
-should be used to sample contours within each `1 x 1' box; the default
-value of `1' is usually sufficient.
-
-   To construct contours for an array of data values on a uniform
-two-dimensional lattice on `box(a,b)', use
-guide[][] contour(real[][] f, pair a, pair b, real[] c,
-                  interpolate join=operator --, int subsample=1);
-
-   To construct contours for an array of data values on a nonoverlapping
-regular mesh specified by the two-dimensional array `z',
-guide[][] contour(pair[][] z, real[][] f, real[] c,
-                  interpolate join=operator --, int subsample=1);
-
- To construct contours for an array of values `f' specified at
-irregularly positioned points `z', use the routine
-guide[][] contour(pair[] z, real[] f, real[] c, interpolate join=operator --);
- The contours themselves can be drawn with one of the routines
-void draw(picture pic=currentpicture, Label[] L=new Label[],
-          guide[][] g, pen p=currentpen);
-
-void draw(picture pic=currentpicture, Label[] L=new Label[],
-          guide[][] g, pen[] p);
-
-   The following simple example draws the contour at value `1' for the
-function z=x^2+y^2, which is a unit circle:
-
-import contour;
-size(75);
-
-real f(real a, real b) {return a^2+b^2;}
-draw(contour(f,(-1,-1),(1,1),new real[] {1}));
-
-
-
-The next example draws and labels multiple contours for the function
-z=x^2-y^2 with the resolution `100 x 100', using a dashed pen for
-negative contours and a solid pen for positive (and zero) contours:
-
-import contour;
-
-size(200);
-
-real f(real x, real y) {return x^2-y^2;}
-int n=10;
-real[] c=new real[n];
-for(int i=0; i < n; ++i) c[i]=(i-n/2)/n;
-
-pen[] p=sequence(new pen(int i) {
-    return (c[i] >= 0 ? solid : dashed)+fontsize(6pt);
-  },c.length);
-
-Label[] Labels=sequence(new Label(int i) {
-    return Label(c[i] != 0 ? (string) c[i] : "",Relative(unitrand()),(0,0),
-                 UnFill(1bp));
-  },c.length);
-
-draw(Labels,contour(f,(-1,-1),(1,1),c),p);
-
-
-
-The next example illustrates how contour lines can be drawn on color
-density images:
-
-import graph;
-import palette;
-import contour;
-
-size(10cm,10cm,IgnoreAspect);
-
-pair a=(0,0);
-pair b=(2pi,2pi);
-
-real f(real x, real y) {return cos(x)*sin(y);}
-
-int N=200;
-int Divs=10;
-int divs=2;
-
-defaultpen(1bp);
-pen Tickpen=black;
-pen tickpen=gray+0.5*linewidth(currentpen);
-pen[] Palette=BWRainbow();
-
-bounds range=image(f,Automatic,a,b,N,Palette);
-
-// Major contours
-
-real[] Cvals=uniform(range.min,range.max,Divs);
-draw(contour(f,a,b,Cvals,N,operator --),Tickpen);
-
-// Minor contours
-real[] cvals;
-for(int i=0; i < Cvals.length-1; ++i)
-  cvals.append(uniform(Cvals[i],Cvals[i+1],divs)[1:divs]);
-draw(contour(f,a,b,cvals,N,operator --),tickpen);
-
-xaxis("$x$",BottomTop,LeftTicks,above=true);
-yaxis("$y$",LeftRight,RightTicks,above=true);
-
-palette("$f(x,y)$",range,point(NW)+(0,0.5),point(NE)+(0,1),Top,Palette,
-        PaletteTicks(N=Divs,n=divs,Tickpen,tickpen));
-
-
-
-Finally, here is an example that illustrates the construction of
-contours from irregularly spaced data:
-
-import contour;
-
-size(200);
-
-int n=100;
-
-real f(real a, real b) {return a^2+b^2;}
-
-srand(1);
-
-real r() {return 1.1*(rand()/randMax*2-1);}
-
-pair[] points=new pair[n];
-real[] values=new real[n];
-
-for(int i=0; i < n; ++i) {
-  points[i]=(r(),r());
-  values[i]=f(points[i].x,points[i].y);
-}
-
-draw(contour(points,values,new real[]{0.25,0.5,1},operator ..),blue);
-
-
-
-In the above example, the contours of irregularly spaced data are
-constructed by first creating a triangular mesh from an array `z' of
-pairs:
-
-int[][] triangulate(pair[] z);
-
-size(200);
-int np=100;
-pair[] points;
-
-real r() {return 1.2*(rand()/randMax*2-1);}
-
-for(int i=0; i < np; ++i)
-  points.push((r(),r()));
-
-int[][] trn=triangulate(points);
-
-for(int i=0; i < trn.length; ++i) {
-  draw(points[trn[i][0]]--points[trn[i][1]]);
-  draw(points[trn[i][1]]--points[trn[i][2]]);
-  draw(points[trn[i][2]]--points[trn[i][0]]);
-}
-
-for(int i=0; i < np; ++i)
-  dot(points[i],red);
-
-
-
-The example `Gouraudcontour' illustrates how to produce color density
-images over such irregular triangular meshes.  `Asymptote' uses a
-robust version of Paul Bourke's Delaunay triangulation algorithm based
-on the public-domain exact arithmetic predicates written by Jonathan
-Shewchuk.
-
-
-File: asymptote.info,  Node: contour3,  Next: slopefield,  Prev: contour,  Up: Base modules
-
-8.37 `contour3'
-===============
-
-This package draws surfaces described as the null space of real-valued
-functions of (x,y,z) or real[][][] matrices.  Its usage is illustrated
-in the example file `magnetic.asy'.
-
-
-File: asymptote.info,  Node: slopefield,  Next: ode,  Prev: contour3,  Up: Base modules
-
-8.38 `slopefield'
-=================
-
-To draw a slope field for the differential equation dy/dx=f(x,y) (or
-dy/dx=f(x)), use:
-picture slopefield(real f(real,real), pair a, pair b,
-                   int nx=nmesh, int ny=nx,
-                   real tickfactor=0.5, pen p=currentpen,
-                   arrowbar arrow=None);
- Here, the points `a' and `b' are the lower left and upper right
-corners of the rectangle in which the slope field is to be drawn, `nx'
-and `ny' are the respective number of ticks in the x and y directions,
-`tickfactor' is the fraction of the minimum cell dimension to use for
-drawing ticks, and `p' is the pen to use for drawing the slope fields.
-The return value is a picture that can be added to `currentpicture' via
-the `add(picture)' command.
-
-   The function 
-path curve(pair c, real f(real,real), pair a, pair b);
- takes a point (`c') and a slope field-defining function `f' and
-returns, as a path, the curve passing through that point. The points
-`a' and `b' represent the rectangular boundaries over which the curve
-is interpolated.
-
-   Both `slopefield' and `curve' alternatively accept a function `real
-f(real)' that depends on x only, as seen in this example:
-
-import slopefield;
-
-size(200);
-
-real func(real x) {return 2x;}
-add(slopefield(func,(-3,-3),(3,3),20,Arrow));
-draw(curve((0,0),func,(-3,-3),(3,3)),red);
-
-
-
-
-File: asymptote.info,  Node: ode,  Prev: slopefield,  Up: Base modules
-
-8.39 `ode'
-==========
-
-The `ode' module, illustrated in the example `odetest.asy', implements
-a number of explicit numerical integration schemes for ordinary
-differential equations.
-
-
-File: asymptote.info,  Node: Options,  Next: Interactive mode,  Prev: Base modules,  Up: Top
-
-9 Command-line options
-**********************
-
-Type `asy -h' to see the full list of command-line options supported by
-`Asymptote':
-
-Usage: ../asy [options] [file ...]
-
-Options (negate by replacing - with -no):
-
--V,-View               View output; command-line only
--a,-align C|B|T|Z      Center, Bottom, Top, or Zero page alignment [C]
--antialias n           Antialiasing width for rasterized output [2]
--arcballradius pixels  Arcball radius [750]
--auto3D                Automatically activate 3D scene [true]
--autobillboard         3D labels always face viewer by default [true]
--autoimport string     Module to automatically import
--autoplain             Enable automatic importing of plain [true]
--autoplay              Autoplay 3D animations [false]
--autorotate            Enable automatic PDF page rotation [false]
--axes3                 Show 3D axes in PDF output [true]
--batchMask             Mask fpu exceptions in batch mode [false]
--batchView             View output in batch mode [false]
--bw                    Convert all colors to black and white [false]
--cd directory          Set current directory; command-line only
--cmyk                  Convert rgb colors to cmyk [false]
--c,-command string     Command to autoexecute
--compact               Conserve memory at the expense of speed [false]
--d,-debug              Enable debugging messages [false]
--divisor n             Garbage collect using purge(divisor=n) [2]
--doubleclick ms        Emulated double-click timeout [200]
--embed                 Embed rendered preview image [true]
--exitonEOF             Exit interactive mode on EOF [true]
--fitscreen             Fit rendered image to screen [true]
--framedelay ms         Additional frame delay [0]
--framerate frames/s    Animation speed [30]
--globalwrite           Allow write to other directory [false]
--gray                  Convert all colors to grayscale [false]
--h,-help               Show summary of options; command-line only
--historylines n        Retain n lines of history [1000]
--iconify               Iconify rendering window [false]
--inlineimage           Generate inline embedded image [false]
--inlinetex             Generate inline TeX code [false]
--interactiveMask       Mask fpu exceptions in interactive mode [true]
--interactiveView       View output in interactive mode [true]
--interactiveWrite      Write expressions entered at the prompt to stdout [true]
--k,-keep               Keep intermediate files [false]
--keepaux               Keep intermediate LaTeX .aux files [false]
--level n               Postscript level [3]
--l,-listvariables      List available global functions and variables [false]
--localhistory          Use a local interactive history file [false]
--loop                  Loop 3D animations [false]
--m,-mask               Mask fpu exceptions; command-line only
--maxtile pair          Maximum rendering tile size [(1024,768)]
--maxviewport pair      Maximum viewport size [(2048,2048)]
--multiline             Input code over multiple lines at the prompt [false]
--multipleView          View output from multiple batch-mode files [false]
--multisample n         Multisampling width for screen images [4]
--offscreen             Use offscreen rendering [false]
--O,-offset pair        PostScript offset [(0,0)]
--f,-outformat format   Convert each output file to specified format
--o,-outname name       Alternative output directory/filename
--p,-parseonly          Parse file [false]
--pdfreload             Automatically reload document in pdfviewer [false]
--pdfreloaddelay usec   Delay before attempting initial pdf reload [750000]
--position pair         Initial 3D rendering screen position [(0,0)]
--prc                   Embed 3D PRC graphics in PDF output [true]
--prompt string         Prompt [> ]
--prompt2 string        Continuation prompt for multiline input  [..]
--q,-quiet              Suppress welcome message [false]
--render n              Render 3D graphics using n pixels per bp (-1=auto) [-1]
--resizestep step       Resize step [1.2]
--reverse               reverse 3D animations [false]
--rgb                   Convert cmyk colors to rgb [false]
--safe                  Disable system call [true]
--scroll n              Scroll standard output n lines at a time [0]
--spinstep deg/s        Spin speed [60]
--svgemulation          Emulate unimplemented SVG shading [false]
--tabcompletion         Interactive prompt auto-completion [true]
--tex engine            latex|pdflatex|xelatex|tex|pdftex|context|none [latex]
--thick                 Render thick 3D lines [true]
--thin                  Render thin 3D lines [true]
--threads               Use POSIX threads for 3D rendering [true]
--toolbar               Show 3D toolbar in PDF output [true]
--s,-translate          Show translated virtual machine code [false]
--twice                 Run LaTeX twice (to resolve references) [false]
--twosided              Use two-sided 3D lighting model for rendering [true]
--u,-user string        General purpose user string
--v,-verbose            Increase verbosity level (can specify multiple times) [0]
--version               Show version; command-line only
--wait                  Wait for child processes to finish before exiting [false]
--warn string           Enable warning; command-line only
--where                 Show where listed variables are declared [false]
--zoomfactor factor     Zoom step factor [1.05]
--zoomstep step         Mouse motion zoom step [0.1]
-
- All boolean options can be negated by prepending `no' to the option
-name.
-
-   If no arguments are given, `Asymptote' runs in interactive mode
-(*note Interactive mode::). In this case, the default output file is
-`out.eps'.
-
-   If `-' is given as the file argument, `Asymptote' reads from
-standard input.
-
-   If multiple files are specified, they are treated as separate
-`Asymptote' runs.
-
-   If the string `autoimport' is nonempty, a module with this name is
-automatically imported for each run as the final step in loading module
-`plain'.
-
-   Default option values may be entered as `Asymptote' code in a
-configuration file named `config.asy' (or the file specified by the
-environment variable `ASYMPTOTE_CONFIG' or `-config' option).
-`Asymptote' will look for this file in its usual search path (*note
-Search paths::). Typically the configuration file is placed in the
-`.asy' directory in the user's home directory (`%USERPROFILE%\.asy'
-under `MSDOS').  Configuration variables are accessed using the long
-form of the option names:
-import settings;
-outformat="pdf";
-batchView=false;
-interactiveView=true;
-batchMask=false;
-interactiveMask=true;
- Command-line options override these defaults. Most configuration
-variables may also be changed at runtime.  The advanced configuration
-variables `dvipsOptions', `hyperrefOptions', `convertOptions',
-`gsOptions', `psviewerOptions', `pdfviewerOptions', and `glOptions'
-allow specialized options to be passed as a string to the respective
-applications or libraries. The default value of `hyperrefOptions' is
-`setpagesize=false,unicode,pdfborder=0 0 0'.
-
-   If you insert
-import plain;
-settings.autoplain=true;
- at the beginning of the configuration file, it can contain arbitrary
-`Asymptote' code.
-
-   The default output format is EPS for the (default) `latex' and `tex'
-tex engine and PDF for the `pdflatex', `xelatex', and `context' tex
-engines.  Alternative output formats may be produced using the `-f'
-option (or `outformat' setting). To produce SVG output, first install
-`dvisvgm' (version 0.8.7 or later) from
-`http://dvisvgm.sourceforge.net/down.html' and be sure to use the
-`latex' or `tex' tex engine.
-
-   `Asymptote' can also produce any output format supported by the
-`ImageMagick' `convert' program (version 6.3.5 or later recommended; an
-`Invalid Parameter' error message indicates that the `MSDOS' utility
-`convert' is being used instead of the one that comes with
-`ImageMagick').  The optional setting `-render n' requests an output
-resolution of `n' pixels per `bp'. Antialiasing is controlled by the
-parameter `antialias', which by default specifies a sampling width of 2
-pixels.  To give other options to `convert', use the `convertOptions'
-setting or call convert manually. This example emulates how `Asymptote'
-produces antialiased `tiff' output at one pixel per `bp':
-asy -o - venn | convert -alpha Off -density 144x144 -geometry 50%x eps:- venn.tiff
-
-   If the option `-nosafe' is given, `Asymptote' runs in unsafe mode.
-This enables the `int system(string s)' and `int system(string[] s)'
-calls, allowing one to execute arbitrary shell commands. The default
-mode, `-safe', disables this call.
-
-   A `PostScript' offset may be specified as a pair (in `bp' units)
-with the `-O' option:
-asy -O 0,0 file
- The default offset is zero. The default value of the page alignment
-setting `align' is `Center'.
-
-   The `-c' (`command') option may be used to execute arbitrary
-`Asymptote' code on the command line as a string. It is not necessary
-to terminate the string with a semicolon. Multiple `-c' options are
-executed in the order they are given. For example
-asy -c 2+2 -c "sin(1)" -c "size(100); draw(unitsquare)"
- produces the output
-4
-0.841470984807897
- and draws a unitsquare of size `100'.
-
-   The `-u' (`user') option may be used to specify arbitrary
-`Asymptote' settings on the command line as a string. It is not
-necessary to terminate the string with a semicolon. Multiple `-u'
-options are executed in the order they are given. Command-line code like
-`-u x=sqrt(2)' can be executed within a module like this:
-real x;
-usersetting();
-write(x);
-
-   When the `-l' (`listvariables') option is used with file arguments,
-only global functions and variables defined in the specified file(s)
-are listed.
-
-   Additional debugging output is produced with each additional `-v'
-option:
-`-v'
-     Display top-level module and final output file names.
-
-`-vv'
-     Also display imported and included module names and final `LaTeX'
-     and `dvips' processing information.
-
-`-vvv'
-     Also output `LaTeX' bidirectional pipe diagnostics.
-
-`-vvvv'
-     Also output knot guide solver diagnostics.
-
-`-vvvvv'
-     Also output `Asymptote' traceback diagnostics.
-
-
-File: asymptote.info,  Node: Interactive mode,  Next: GUI,  Prev: Options,  Up: Top
-
-10 Interactive mode
-*******************
-
-Interactive mode is entered by executing the command `asy' with no file
-arguments. When the `-multiline' option is disabled (the default), each
-line must be a complete `Asymptote' statement (unless explicitly
-continued by a final backslash character `\'); it is not necessary to
-terminate input lines with a semicolon.  If one assigns
-`settings.multiline=true', interactive code can be entered over
-multiple lines; in this mode, the automatic termination of interactive
-input lines by a semicolon is inhibited. Multiline mode is useful for
-cutting and pasting `Asymptote' code directly into the interactive
-input buffer.
-
-   Interactive mode can be conveniently used as a calculator:
-expressions entered at the interactive prompt (for which a
-corresponding `write' function exists) are automatically evaluated and
-written to `stdout'.  If the expression is non-writable, its type
-signature will be printed out instead. In either case, the expression
-can be referred to using the symbol `%' in the next line input at the
-prompt.  For example:
-> 2+3
-5
-> %*4
-20
-> 1/%
-0.05
-> sin(%)
-0.0499791692706783
-> currentpicture
-<picture currentpicture>
-> %.size(200,0)
->
-
-   The `%' symbol, when used as a variable, is shorthand for the
-identifier `operator answer', which is set by the prompt after each
-written expression evaluation.
-
-   The following special commands are supported only in interactive mode
-and must be entered immediately after the prompt:
-
-`help'
-     view the manual;
-
-`erase'
-     erase `currentpicture'; 
-
-`reset'
-     reset the `Asymptote' environment to its initial state, except for
-     changes to the settings module (*note settings::), the current
-     directory (*note cd::), and breakpoints (*note Debugger::); 
-
-`input FILE'
-     does an interactive reset, followed by the command `include FILE'.
-     If the file name `FILE' contains nonalphanumeric characters,
-     enclose it with quotation marks.  A trailing semi-colon followed
-     by optional `Asymptote' commands may be entered on the same line.  
-
-`quit'
-     exit interactive mode (`exit' is a synonym; the abbreviation `q'
-     is also accepted unless there exists a top-level variable named
-     `q').  A history of the most recent 1000 (this number can be
-     changed with the `historylines' configuration variable) previous
-     commands will be retained in the file `.asy/history' in the user's
-     home directory (unless the command-line option `-localhistory' was
-     specified, in which case the history will be stored in the file
-     `.asy_history' in the current directory).
-
-
-   Typing `ctrl-C' interrupts the execution of `Asymptote' code and
-returns control to the interactive prompt.
-
-   Interactive mode is implemented with the GNU `readline' library,
-with command history and auto-completion. To customize the key
-bindings, see:
-`http://cnswww.cns.cwru.edu/php/chet/readline/readline.html'
-
-   The file `asymptote.py' in the `Asymptote' system directory provides
-an alternative way of entering `Asymptote' commands interactively,
-coupled with the full power of `Python'. Copy this file to your `Python
-path' and then execute from within `Python' the commands
-from asymptote import *
-g=asy()
-g.size(200)
-g.draw("unitcircle")
-g.send("draw(unitsquare)")
-g.fill("unitsquare, blue")
-g.clip("unitcircle")
-g.label("\"$O$\", (0,0), SW")
-
-
-File: asymptote.info,  Node: GUI,  Next: PostScript to Asymptote,  Prev: Interactive mode,  Up: Top
-
-11 Graphical User Interface
-***************************
-
-In the event that adjustments to the final figure are required, the
-preliminary Graphical User Interface (GUI) `xasy' included with
-`Asymptote' allows you to move graphical objects and draw new ones.
-The modified figure can then be saved as a normal `Asymptote' file.
-
-* Menu:
-
-* GUI installation::            Installing `xasy'
-* GUI usage::
-
-
-File: asymptote.info,  Node: GUI installation,  Next: GUI usage,  Up: GUI
-
-11.1 GUI installation
-=====================
-
-As `xasy' is written in the interactive scripting language `Python/TK',
-it requires `Python' (`http://www.python.org'), the `Python Imaging
-Library' (`http://www.pythonware.com/products/pil/'), and the `tkinter'
-package (included with `Python' under `Microsoft Windows') be
-installed. `Fedora Linux' users can either install `tkinter' with the
-commands
-yum install tkinter
-yum install tk-devel
- or manually install the `tkinter', `tix', `tk', and `tk-devel'
-packages.
-
-   Pictures are deconstructed into the PNG image format, which supports
-full alpha channel transparency. Under `Microsoft Windows', this
-requires `Python 2.7.4' and the `Python Imaging Library':
-
-     `http://www.python.org/ftp/python/2.7.4/python-2.7.4.msi'
-
-     `http://effbot.org/downloads/PIL-1.1.7.win32-py2.7.exe'.
-   On `UNIX' systems, place
-`http://effbot.org/downloads/Imaging-1.1.7.tar.gz' in the `Asymptote'
-source directory, and type (as the root user):
-tar -zxf Imaging-1.1.7.tar.gz
-cd Imaging-1.1.7
-python setup.py install
-
-
-File: asymptote.info,  Node: GUI usage,  Prev: GUI installation,  Up: GUI
-
-11.2 GUI usage
-==============
-
-A wheel mouse is convenient for raising and lowering objects within
-`xasy', to expose the object to be moved. If a wheel mouse is not
-available, mouse `Button-2' can be used to repeatedly lower an object
-instead. When run from the command line, `xasy' accepts a command line
-option `-x n', which sets the initial magnification to `n'.
-
-   Deconstruction of compound objects (such as arrows) can be prevented
-by enclosing them within the commands
-void begingroup(picture pic=currentpicture);
-void endgroup(picture pic=currentpicture);
- By default, the elements of a picture or frame will be grouped
-together on adding them to a picture. However, the elements of a frame
-added to another frame are not grouped together by default: their
-elements will be individually deconstructed (*note add::).
-
-
-File: asymptote.info,  Node: PostScript to Asymptote,  Next: Help,  Prev: GUI,  Up: Top
-
-12 `PostScript' to `Asymptote'
-******************************
-
-The excellent `PostScript' editor `pstoedit' (version 3.50 or later;
-available from `http://sourceforge.net/projects/pstoedit/') includes an
-`Asymptote' backend. Unlike virtually all other `pstoedit' backends,
-this driver includes native clipping, even-odd fill rule, `PostScript'
-subpath, and full image support. Here is an example: `asy -V
-/usr/local/share/doc/asymptote/examples/venn.asy'
-pstoedit -f asy venn.eps test.asy
-asy -V test
-
-If the line widths aren't quite correct, try giving `pstoedit' the
-`-dis' option.  If the fonts aren't typeset correctly, try giving
-`pstoedit' the `-dt' option.
-
-
-File: asymptote.info,  Node: Help,  Next: Debugger,  Prev: PostScript to Asymptote,  Up: Top
-
-13 Help
-*******
-
-A list of frequently asked questions (FAQ) is maintained at
-
-     `http://asymptote.sourceforge.net/FAQ'
-   Questions on installing and using `Asymptote' that are not addressed
-in the FAQ should be sent to the `Asymptote' forum:
-
-     `http://sourceforge.net/projects/asymptote/forums/forum/409349'
-   Including an example that illustrates what you are trying to do will
-help you get useful feedback.  `LaTeX' problems can often be diagnosed
-with the `-vv' or `-vvv' command-line options.  Contributions in the
-form of patches or `Asymptote' modules can be posted here:
-
-     `http://sourceforge.net/tracker/?atid=685685&group_id=120000'
-   To receive announcements of upcoming releases, please subscribe to
-`Asymptote' at
-
-     `http://freshmeat.net/projects/asy'
-   If you find a bug in `Asymptote', please check (if possible) whether
-the bug is still present in the latest `Subversion' developmental code
-(*note Subversion::) before submitting a bug report. New bugs can be
-submitted using the Bug Tracking System at
-
-     `http://sourceforge.net/projects/asymptote'
-   To see if the bug has already been fixed, check bugs with Status
-`Closed' and recent lines in
-
-     `http://asymptote.sourceforge.net/ChangeLog'
-   `Asymptote' can be configured with the optional GNU library
-`libsigsegv', available from `http://libsigsegv.sourceforge.net', which
-allows one to distinguish user-generated `Asymptote' stack overflows
-(*note stack overflow::) from true segmentation faults (due to internal
-C++ programming errors; please submit the `Asymptote' code that
-generates such segmentation faults along with your bug report).
-
-
-File: asymptote.info,  Node: Debugger,  Next: Credits,  Prev: Help,  Up: Top
-
-14 Debugger
-***********
-
-Asymptote now includes a line-based (as opposed to code-based) debugger
-that can assist the user in following flow control. To set a break
-point in file `file' at line `line', use the command
-
-void stop(string file, int line, code s=quote{});
- The optional argument `s' may be used to conditionally set the variable
-`ignore' in `plain_debugger.asy' to `true'. For example, the first 10
-instances of this breakpoint will be ignored (the variable `int
-count=0' is defined in `plain_debugger.asy'):
-stop("test",2,quote{ignore=(++count <= 10);});
-
-   To set a break point in file `file' at the first line containing the
-string `text', use
-
-void stop(string file, string text, code s=quote{});
- To list all breakpoints, use: 
-void breakpoints();
- To clear a breakpoint, use: 
-void clear(string file, int line);
- To clear all breakpoints, use:
-void clear();
-
-   The following commands may be entered at the debugging prompt:
-
-``h''
-     help; 
-
-``c''
-     continue execution;
-
-``i''
-     step to the next instruction;
-
-``s''
-     step to the next executable line;
-
-``n''
-     step to the next executable line in the current file;
-
-``f''
-     step to the next file;
-
-``r''
-     return to the file associated with the most recent breakpoint;
-
-``t''
-     toggle tracing (`-vvvvv') mode;
-
-``q''
-     quit debugging and end execution;
-
-``x''
-     exit the debugger and run to completion.
-
-   Arbitrary `Asymptote' code may also be entered at the debugging
-prompt; however, since the debugger is implemented with `eval',
-currently only top-level (global) variables can be displayed or
-modified.
-
-   The debugging prompt may be entered manually with the call
-void breakpoint(code s=quote{});
-
-
-File: asymptote.info,  Node: Credits,  Next: Index,  Prev: Debugger,  Up: Top
-
-15 Acknowledgments
-******************
-
-Financial support for the development of `Asymptote' was generously
-provided by the Natural Sciences and Engineering Research Council of
-Canada, the Pacific Institute for Mathematical Sciences, and the
-University of Alberta Faculty of Science.
-
-   We also would like to acknowledge the previous work of John D. Hobby,
-author of the program `MetaPost' that inspired the development of
-`Asymptote', and Donald E. Knuth, author of TeX and `MetaFont' (on
-which `MetaPost' is based).
-
-   The authors of `Asymptote' are Andy Hammerlindl, John Bowman, and
-Tom Prince. Sean Healy designed the `Asymptote' logo. Other
-contributors include Michail Vidiassov, Radoslav Marinov, Orest Shardt,
-Chris Savage, Philippe Ivaldi, Olivier Guibe', Jacques Pienaar, Mark
-Henning, Steve Melenchuk, Martin Wiebusch, and Stefan Knorr.
-
-
-File: asymptote.info,  Node: Index,  Prev: Credits,  Up: Top
-
-Index
-*****
-
-
-* Menu:
-
-* !:                                     Arithmetic & logical.
-                                                              (line  68)
-* != <1>:                                Arithmetic & logical.
-                                                              (line  38)
-* !=:                                    Structures.          (line  52)
-* % <1>:                                 Interactive mode.    (line  17)
-* %:                                     Arithmetic & logical.
-                                                              (line  23)
-* %=:                                    Self & prefix operators.
-                                                              (line   6)
-* & <1>:                                 Arithmetic & logical.
-                                                              (line  56)
-* &:                                     Bezier curves.       (line  86)
-* &&:                                    Arithmetic & logical.
-                                                              (line  53)
-* * <1>:                                 Arithmetic & logical.
-                                                              (line  17)
-* *:                                     Pens.                (line  15)
-* **:                                    Arithmetic & logical.
-                                                              (line  31)
-* *=:                                    Self & prefix operators.
-                                                              (line   6)
-* + <1>:                                 Arithmetic & logical.
-                                                              (line  13)
-* +:                                     Pens.                (line  15)
-* ++:                                    Self & prefix operators.
-                                                              (line   6)
-* +=:                                    Self & prefix operators.
-                                                              (line   6)
-* -:                                     Arithmetic & logical.
-                                                              (line  14)
-* -- <1>:                                Self & prefix operators.
-                                                              (line   6)
-* --:                                    Tutorial.            (line 127)
-* ---:                                   Bezier curves.       (line  86)
-* -=:                                    Self & prefix operators.
-                                                              (line   6)
-* -c:                                    Options.             (line 175)
-* -l:                                    Options.             (line 194)
-* -u:                                    Options.             (line 185)
-* -V <1>:                                Tutorial.            (line  19)
-* -V:                                    Configuring.         (line   6)
-* ..:                                    Tutorial.            (line 127)
-* .asy:                                  Search paths.        (line  14)
-* /:                                     Arithmetic & logical.
-                                                              (line  20)
-* /=:                                    Self & prefix operators.
-                                                              (line   6)
-* 2D graphs:                             graph.               (line   6)
-* 3D graphs:                             graph3.              (line   6)
-* 3D grids:                              grid3.               (line   6)
-* 3D PostScript:                         three.               (line 593)
-* ::                                     Arithmetic & logical.
-                                                              (line  73)
-* :::                                    Bezier curves.       (line  70)
-* <:                                     Arithmetic & logical.
-                                                              (line  41)
-* <=:                                    Arithmetic & logical.
-                                                              (line  44)
-* == <1>:                                Arithmetic & logical.
-                                                              (line  37)
-* ==:                                    Structures.          (line  52)
-* >:                                     Arithmetic & logical.
-                                                              (line  50)
-* >=:                                    Arithmetic & logical.
-                                                              (line  47)
-* ?:                                     Arithmetic & logical.
-                                                              (line  73)
-* ^:                                     Arithmetic & logical.
-                                                              (line  28)
-* ^=:                                    Self & prefix operators.
-                                                              (line   6)
-* ^^:                                    Tutorial.            (line 134)
-* a4:                                    Configuring.         (line  61)
-* abort:                                 Data types.          (line 339)
-* abs <1>:                               Mathematical functions.
-                                                              (line  35)
-* abs:                                   Data types.          (line  62)
-* accel <1>:                             three.               (line 519)
-* accel:                                 Paths and guides.    (line 115)
-* access:                                Import.              (line   6)
-* acknowledgments:                       Credits.             (line   6)
-* aCos:                                  Mathematical functions.
-                                                              (line  20)
-* acos:                                  Mathematical functions.
-                                                              (line   6)
-* acosh:                                 Mathematical functions.
-                                                              (line   6)
-* add <1>:                               three.               (line 283)
-* add:                                   Frames and pictures. (line 196)
-* addViews:                              three.               (line 405)
-* adjust:                                Pens.                (line 115)
-* Ai:                                    Mathematical functions.
-                                                              (line  48)
-* Ai_deriv:                              Mathematical functions.
-                                                              (line  48)
-* Airy:                                  Mathematical functions.
-                                                              (line  48)
-* alias <1>:                             Arrays.              (line 181)
-* alias:                                 Structures.          (line  52)
-* align:                                 Options.             (line 169)
-* Align:                                 label.               (line  12)
-* all:                                   Arrays.              (line 329)
-* Allow:                                 Pens.                (line 327)
-* AND:                                   Arithmetic & logical.
-                                                              (line  80)
-* and:                                   Bezier curves.       (line  56)
-* angle:                                 Data types.          (line  70)
-* animate <1>:                           animation.           (line  12)
-* animate <2>:                           Files.               (line 154)
-* animate:                               Configuring.         (line  67)
-* animation:                             animation.           (line   6)
-* annotate:                              annotate.            (line   6)
-* antialias <1>:                         Options.             (line 144)
-* antialias:                             three.               (line 222)
-* append <1>:                            Arrays.              (line  39)
-* append:                                Files.               (line  36)
-* arc:                                   three.               (line 295)
-* Arc:                                   Paths and guides.    (line  32)
-* arc:                                   Paths and guides.    (line  22)
-* ArcArrow:                              draw.                (line  26)
-* ArcArrow3:                             three.               (line 560)
-* ArcArrows:                             draw.                (line  26)
-* ArcArrows3:                            three.               (line 560)
-* arclength <1>:                         three.               (line 519)
-* arclength:                             Paths and guides.    (line 142)
-* arcpoint:                              Paths and guides.    (line 152)
-* arctime <1>:                           three.               (line 519)
-* arctime:                               Paths and guides.    (line 146)
-* arguments:                             Default arguments.   (line   6)
-* arithmetic operators:                  Arithmetic & logical.
-                                                              (line   6)
-* array:                                 Arrays.              (line 122)
-* array iteration:                       Programming.         (line  33)
-* arrays:                                Arrays.              (line   6)
-* arrow:                                 label.               (line  71)
-* Arrow:                                 draw.                (line  26)
-* arrow:                                 Drawing commands.    (line  31)
-* arrow keys:                            Tutorial.            (line  37)
-* Arrow3:                                three.               (line 560)
-* Arrows:                                draw.                (line  26)
-* arrows:                                draw.                (line  26)
-* Arrows3:                               three.               (line 560)
-* as:                                    Import.              (line  68)
-* ascii:                                 Data types.          (line 286)
-* aSin:                                  Mathematical functions.
-                                                              (line  20)
-* asin:                                  Mathematical functions.
-                                                              (line   6)
-* asinh:                                 Mathematical functions.
-                                                              (line   6)
-* Aspect:                                Frames and pictures. (line  54)
-* assert:                                Data types.          (line 344)
-* assignment:                            Programming.         (line   8)
-* asy <1>:                               Import.              (line 102)
-* asy:                                   Data types.          (line 334)
-* asy-mode:                              Editing modes.       (line   6)
-* asy.vim:                               Editing modes.       (line  33)
-* asyinclude:                            LaTeX usage.         (line  46)
-* asymptote.sty:                         LaTeX usage.         (line   6)
-* asymptote.xml:                         Editing modes.       (line  49)
-* ASYMPTOTE_CONFIG:                      Options.             (line 116)
-* aTan:                                  Mathematical functions.
-                                                              (line  20)
-* atan:                                  Mathematical functions.
-                                                              (line   6)
-* atan2:                                 Mathematical functions.
-                                                              (line   6)
-* atanh:                                 Mathematical functions.
-                                                              (line   6)
-* atleast:                               Bezier curves.       (line  56)
-* attach <1>:                            graph.               (line 416)
-* attach <2>:                            LaTeX usage.         (line  51)
-* attach:                                Frames and pictures. (line 252)
-* autoadjust:                            three.               (line 371)
-* autoimport:                            Options.             (line 112)
-* automatic scaling:                     graph.               (line 682)
-* axialshade:                            fill.                (line  43)
-* axis <1>:                              graph3.              (line  67)
-* axis:                                  graph.               (line 879)
-* azimuth:                               Data types.          (line 126)
-* babel:                                 babel.               (line   6)
-* background color:                      Frames and pictures. (line 168)
-* BackView:                              three.               (line 398)
-* Bar:                                   draw.                (line  19)
-* Bar3:                                  three.               (line 560)
-* Bars:                                  draw.                (line  19)
-* Bars3:                                 three.               (line 560)
-* barsize:                               draw.                (line  19)
-* base modules:                          Base modules.        (line   6)
-* basealign:                             Pens.                (line 168)
-* baseline:                              label.               (line  91)
-* batch mode:                            Tutorial.            (line   6)
-* beep:                                  Data types.          (line 357)
-* BeginArcArrow:                         draw.                (line  26)
-* BeginArcArrow3:                        three.               (line 560)
-* BeginArrow:                            draw.                (line  26)
-* BeginArrow3:                           three.               (line 560)
-* BeginBar:                              draw.                (line  19)
-* BeginBar3:                             three.               (line 560)
-* BeginDotMargin:                        draw.                (line  42)
-* BeginDotMargin3:                       three.               (line 576)
-* BeginMargin:                           draw.                (line  42)
-* BeginMargin3:                          three.               (line 576)
-* BeginPenMargin:                        draw.                (line  42)
-* BeginPenMargin2:                       three.               (line 576)
-* BeginPenMargin3:                       three.               (line 576)
-* BeginPoint:                            label.               (line  56)
-* Bessel:                                Mathematical functions.
-                                                              (line  48)
-* bevel:                                 flowchart.           (line  75)
-* beveljoin:                             Pens.                (line 138)
-* Bezier curves:                         Bezier curves.       (line   6)
-* bezulate:                              three.               (line 104)
-* Bi:                                    Mathematical functions.
-                                                              (line  48)
-* Bi_deriv:                              Mathematical functions.
-                                                              (line  48)
-* Billboard:                             three.               (line 489)
-* binary:                                Files.               (line  75)
-* binary format:                         Files.               (line  75)
-* binary operators:                      Arithmetic & logical.
-                                                              (line   6)
-* binarytree:                            binarytree.          (line   6)
-* black stripes:                         three.               (line 222)
-* Blank:                                 draw.                (line  26)
-* block.bottom:                          flowchart.           (line  19)
-* block.bottomleft:                      flowchart.           (line  19)
-* block.bottomright:                     flowchart.           (line  19)
-* block.center:                          flowchart.           (line  26)
-* block.draw:                            flowchart.           (line  31)
-* block.left:                            flowchart.           (line  19)
-* block.position:                        flowchart.           (line  24)
-* block.right:                           flowchart.           (line  19)
-* block.top:                             flowchart.           (line  19)
-* block.topleft:                         flowchart.           (line  19)
-* block.topright:                        flowchart.           (line  19)
-* bool:                                  Data types.          (line  14)
-* bool3:                                 Data types.          (line  23)
-* boolean operators:                     Arithmetic & logical.
-                                                              (line   6)
-* Bottom:                                graph.               (line 134)
-* BottomTop:                             graph.               (line 140)
-* BottomView:                            three.               (line 398)
-* bounding box:                          Frames and pictures. (line 168)
-* Bounds:                                graph3.              (line  21)
-* box <1>:                               three.               (line 317)
-* box:                                   Frames and pictures. (line  22)
-* bp:                                    Tutorial.            (line  26)
-* break:                                 Programming.         (line  29)
-* breakpoints:                           Debugger.            (line  21)
-* brick:                                 Pens.                (line 251)
-* broken axis:                           graph.               (line 782)
-* bug reports:                           Help.                (line  23)
-* buildcycle:                            Paths and guides.    (line 258)
-* Button-1:                              GUI.                 (line   6)
-* Button-2:                              GUI.                 (line   6)
-* BWRainbow:                             palette.             (line  15)
-* BWRainbow2:                            palette.             (line  18)
-* C string:                              Data types.          (line 191)
-* CAD:                                   CAD.                 (line   6)
-* calculateTransform:                    Frames and pictures. (line 107)
-* camera:                                three.               (line 366)
-* casts:                                 Casts.               (line   6)
-* cbrt:                                  Mathematical functions.
-                                                              (line   6)
-* cd:                                    Files.               (line  25)
-* ceil:                                  Mathematical functions.
-                                                              (line  26)
-* center:                                three.               (line 350)
-* Center:                                label.               (line  61)
-* checker:                               Pens.                (line 251)
-* Chinese:                               unicode.             (line  12)
-* choose:                                Mathematical functions.
-                                                              (line  39)
-* Ci:                                    Mathematical functions.
-                                                              (line  48)
-* circle <1>:                            flowchart.           (line  64)
-* circle:                                three.               (line 291)
-* Circle:                                Paths and guides.    (line  17)
-* circle:                                Paths and guides.    (line  10)
-* circlebarframe:                        markers.             (line  18)
-* CJK:                                   unicode.             (line  12)
-* clamped:                               graph.               (line  37)
-* clear <1>:                             Debugger.            (line  23)
-* clear:                                 Files.               (line  92)
-* clip:                                  fill.                (line 115)
-* CLZ:                                   Arithmetic & logical.
-                                                              (line  80)
-* cm:                                    Tutorial.            (line  63)
-* cmd:                                   Configuring.         (line  34)
-* cmyk:                                  Pens.                (line  34)
-* colatitude:                            Data types.          (line 131)
-* color:                                 Pens.                (line  23)
-* coloredNodes:                          tube.                (line  25)
-* coloredpath:                           tube.                (line  18)
-* coloredSegments:                       tube.                (line  25)
-* colorless:                             Pens.                (line  54)
-* colors:                                Pens.                (line  51)
-* comma:                                 Files.               (line  61)
-* comma-separated-value mode:            Arrays.              (line 362)
-* command-line options <1>:              Options.             (line   6)
-* command-line options:                  Configuring.         (line  83)
-* comment character:                     Files.               (line  16)
-* compass directions:                    Tutorial.            (line 106)
-* Compiling from UNIX source:            Compiling from UNIX source.
-                                                              (line   6)
-* complement:                            Arrays.              (line 150)
-* concat:                                Arrays.              (line 177)
-* conditional <1>:                       Arithmetic & logical.
-                                                              (line  73)
-* conditional:                           Programming.         (line   8)
-* config:                                Options.             (line 116)
-* configuration file <1>:                Options.             (line 116)
-* configuration file:                    Configuring.         (line  23)
-* configuring:                           Configuring.         (line   6)
-* conj:                                  Data types.          (line  59)
-* constructors:                          Structures.          (line  91)
-* context:                               Options.             (line 144)
-* continue <1>:                          Debugger.            (line  31)
-* continue:                              Programming.         (line  29)
-* contour:                               contour.             (line   9)
-* contour3:                              contour3.            (line   6)
-* controls <1>:                          three.               (line   6)
-* controls:                              Bezier curves.       (line  45)
-* controlSpecifier:                      Paths and guides.    (line 382)
-* convert <1>:                           Options.             (line 144)
-* convert <2>:                           animation.           (line   6)
-* convert <3>:                           Files.               (line 154)
-* convert:                               Configuring.         (line  67)
-* convertOptions:                        Options.             (line 131)
-* Coons shading:                         fill.                (line  78)
-* copy:                                  Arrays.              (line 174)
-* Cos:                                   Mathematical functions.
-                                                              (line  20)
-* cos:                                   Mathematical functions.
-                                                              (line   6)
-* cosh:                                  Mathematical functions.
-                                                              (line   6)
-* cputime:                               Structures.          (line 169)
-* crop:                                  graph.               (line 637)
-* cropping graphs:                       graph.               (line 637)
-* cross <1>:                             graph.               (line 485)
-* cross:                                 Data types.          (line 169)
-* crossframe:                            markers.             (line  23)
-* crosshatch:                            Pens.                (line 267)
-* csv:                                   Arrays.              (line 362)
-* CTZ:                                   Arithmetic & logical.
-                                                              (line  80)
-* cubicroots:                            Arrays.              (line 318)
-* curl <1>:                              three.               (line   6)
-* curl:                                  Bezier curves.       (line  66)
-* curlSpecifier:                         Paths and guides.    (line 394)
-* currentpen:                            Pens.                (line   6)
-* currentprojection:                     three.               (line 395)
-* curve:                                 slopefield.          (line  20)
-* custom axis types:                     graph.               (line 144)
-* custom mark routine:                   graph.               (line 577)
-* custom tick locations:                 graph.               (line 249)
-* cut:                                   Paths and guides.    (line 240)
-* cycle <1>:                             three.               (line   6)
-* cycle:                                 Tutorial.            (line  75)
-* cyclic <1>:                            three.               (line 519)
-* cyclic <2>:                            Arrays.              (line  39)
-* cyclic:                                Paths and guides.    (line  74)
-* Cyrillic:                              unicode.             (line   7)
-* dashdotted:                            Pens.                (line  95)
-* dashed:                                Pens.                (line  95)
-* data types:                            Data types.          (line   6)
-* date:                                  Data types.          (line 298)
-* Debian:                                UNIX binary distributions.
-                                                              (line  19)
-* debugger:                              Debugger.            (line   6)
-* declaration:                           Programming.         (line   8)
-* deconstruct:                           GUI usage.           (line   6)
-* default arguments:                     Default arguments.   (line   6)
-* defaultformat:                         graph.               (line 175)
-* DefaultHead:                           draw.                (line  26)
-* DefaultHead3:                          three.               (line 560)
-* defaultpen:                            Pens.                (line  46)
-* defaultrender:                         three.               (line  47)
-* deferred drawing:                      simplex.             (line   6)
-* Degrees:                               Mathematical functions.
-                                                              (line  17)
-* degrees <1>:                           Mathematical functions.
-                                                              (line  17)
-* degrees:                               Data types.          (line  75)
-* delete <1>:                            Arrays.              (line  39)
-* delete:                                Files.               (line 149)
-* description:                           Description.         (line   6)
-* diagonal:                              Arrays.              (line 303)
-* diamond:                               flowchart.           (line  57)
-* dimension:                             Arrays.              (line 367)
-* dir <1>:                               three.               (line 519)
-* dir <2>:                               Paths and guides.    (line  98)
-* dir <3>:                               Data types.          (line  87)
-* dir:                                   Search paths.        (line  10)
-* direction specifier:                   Bezier curves.       (line   6)
-* directory:                             Files.               (line  25)
-* dirSpecifier:                          Paths and guides.    (line 376)
-* dirtime:                               Paths and guides.    (line 155)
-* display:                               Configuring.         (line  67)
-* do:                                    Programming.         (line  29)
-* DOSendl:                               Files.               (line  61)
-* DOSnewl:                               Files.               (line  61)
-* dot <1>:                               Arrays.              (line 259)
-* dot <2>:                               Data types.          (line 100)
-* dot:                                   draw.                (line  83)
-* DotMargin:                             draw.                (line  42)
-* DotMargin3:                            three.               (line 576)
-* DotMargins:                            draw.                (line  42)
-* DotMargins3:                           three.               (line 576)
-* dotted:                                Pens.                (line  95)
-* double deferred drawing:               three.               (line 268)
-* double precision:                      Files.               (line  75)
-* draw:                                  three.               (line 112)
-* Draw:                                  Frames and pictures. (line 147)
-* draw:                                  draw.                (line 110)
-* Draw:                                  draw.                (line  26)
-* draw:                                  Drawing commands.    (line  31)
-* drawing commands:                      Drawing commands.    (line   6)
-* drawline:                              math.                (line   9)
-* drawtree:                              drawtree.            (line   9)
-* dvips:                                 Configuring.         (line  67)
-* dvipsOptions:                          Options.             (line 131)
-* dvisvgm:                               Configuring.         (line  67)
-* E <1>:                                 Mathematical functions.
-                                                              (line  48)
-* E:                                     Tutorial.            (line 106)
-* Editing modes:                         Editing modes.       (line   6)
-* Ei:                                    Mathematical functions.
-                                                              (line  48)
-* ellipse <1>:                           Frames and pictures. (line  22)
-* ellipse:                               Paths and guides.    (line  39)
-* elliptic functions:                    Mathematical functions.
-                                                              (line  48)
-* else:                                  Programming.         (line   8)
-* emacs:                                 Editing modes.       (line   6)
-* embed:                                 embed.               (line   6)
-* Embedded:                              three.               (line 489)
-* empty:                                 Frames and pictures. (line   7)
-* EndArcArrow:                           draw.                (line  26)
-* EndArcArrow3:                          three.               (line 560)
-* EndArrow:                              draw.                (line  26)
-* EndArrow3:                             three.               (line 560)
-* EndBar:                                draw.                (line  19)
-* EndBar3:                               three.               (line 560)
-* EndDotMargin:                          draw.                (line  42)
-* EndDotMargin3:                         three.               (line 576)
-* endl:                                  Files.               (line  61)
-* EndMargin:                             draw.                (line  42)
-* EndMargin3:                            three.               (line 576)
-* EndPenMargin:                          draw.                (line  42)
-* EndPenMargin2:                         three.               (line 576)
-* EndPenMargin3:                         three.               (line 576)
-* EndPoint:                              label.               (line  56)
-* envelope:                              Frames and pictures. (line  22)
-* environment variables:                 Configuring.         (line  87)
-* eof <1>:                               Arrays.              (line 344)
-* eof:                                   Files.               (line  92)
-* eol <1>:                               Arrays.              (line 344)
-* eol:                                   Files.               (line  92)
-* EPS <1>:                               Options.             (line 144)
-* EPS:                                   label.               (line  79)
-* erase <1>:                             Frames and pictures. (line   7)
-* erase <2>:                             Data types.          (line 241)
-* erase:                                 Tutorial.            (line  37)
-* erf:                                   Mathematical functions.
-                                                              (line   6)
-* erfc:                                  Mathematical functions.
-                                                              (line   6)
-* error:                                 Files.               (line  16)
-* error bars:                            graph.               (line 533)
-* errorbars:                             graph.               (line 485)
-* eval:                                  Import.              (line  98)
-* evenodd <1>:                           Pens.                (line 152)
-* evenodd:                               Tutorial.            (line 148)
-* exit <1>:                              Debugger.            (line  57)
-* exit <2>:                              Interactive mode.    (line  59)
-* exit:                                  Data types.          (line 348)
-* exp:                                   Mathematical functions.
-                                                              (line   6)
-* expi:                                  Data types.          (line  83)
-* explicit:                              Casts.               (line   6)
-* explicit casts:                        Casts.               (line  21)
-* expm1:                                 Mathematical functions.
-                                                              (line   6)
-* exponential integral:                  Mathematical functions.
-                                                              (line  48)
-* extendcap:                             Pens.                (line 129)
-* extension <1>:                         MetaPost.            (line  10)
-* extension:                             Paths and guides.    (line 235)
-* external:                              embed.               (line  13)
-* extrude:                               three.               (line 513)
-* F:                                     Mathematical functions.
-                                                              (line  48)
-* fabs:                                  Mathematical functions.
-                                                              (line   6)
-* face:                                  three.               (line 601)
-* factorial:                             Mathematical functions.
-                                                              (line  39)
-* Fedora:                                UNIX binary distributions.
-                                                              (line  15)
-* feynman:                               feynman.             (line   6)
-* fft <1>:                               math.                (line  26)
-* fft:                                   Arrays.              (line 246)
-* FFTW:                                  Compiling from UNIX source.
-                                                              (line  57)
-* file <1>:                              Debugger.            (line  45)
-* file:                                  Files.               (line   6)
-* Fill:                                  Frames and pictures. (line 133)
-* fill <1>:                              fill.                (line  17)
-* fill:                                  draw.                (line 116)
-* Fill:                                  draw.                (line  26)
-* FillDraw:                              Frames and pictures. (line 123)
-* filldraw:                              fill.                (line  11)
-* FillDraw:                              draw.                (line  26)
-* filloutside:                           fill.                (line  27)
-* fillrule:                              Pens.                (line 152)
-* find <1>:                              Arrays.              (line 159)
-* find:                                  Data types.          (line 226)
-* firstcut:                              Paths and guides.    (line 250)
-* fit:                                   Frames and pictures. (line 103)
-* fit3:                                  three.               (line 281)
-* fixedscaling:                          Frames and pictures. (line  74)
-* floor:                                 Mathematical functions.
-                                                              (line  26)
-* flowchart:                             flowchart.           (line   6)
-* flush:                                 Files.               (line  61)
-* fmod:                                  Mathematical functions.
-                                                              (line   6)
-* font:                                  Pens.                (line 192)
-* font command:                          Pens.                (line 192)
-* fontcommand:                           Pens.                (line 207)
-* fontsize:                              Pens.                (line 178)
-* for:                                   Programming.         (line   8)
-* format <1>:                            Options.             (line 144)
-* format:                                Data types.          (line 269)
-* forum:                                 Help.                (line   6)
-* frame:                                 Frames and pictures. (line   7)
-* from:                                  Import.              (line  17)
-* FrontView:                             three.               (line 398)
-* function declarations:                 Functions.           (line  67)
-* function shading:                      fill.                (line 100)
-* Function shading:                      fill.                (line 100)
-* functions <1>:                         Mathematical functions.
-                                                              (line   6)
-* functions:                             Functions.           (line   6)
-* functionshade:                         fill.                (line 100)
-* gamma:                                 Mathematical functions.
-                                                              (line   6)
-* Gaussrand:                             Mathematical functions.
-                                                              (line  39)
-* geometry:                              geometry.            (line   6)
-* getc:                                  Files.               (line  30)
-* getpair:                               Files.               (line 117)
-* getreal:                               Files.               (line 117)
-* getstring:                             Files.               (line 117)
-* gettriple:                             Files.               (line 117)
-* glOptions <1>:                         Options.             (line 131)
-* glOptions:                             three.               (line 222)
-* GNU Scientific Library:                Mathematical functions.
-                                                              (line  48)
-* gouraudshade:                          fill.                (line  62)
-* Gradient:                              palette.             (line  25)
-* gradient shading:                      fill.                (line  32)
-* graph:                                 graph.               (line   6)
-* graph3:                                graph3.              (line   6)
-* graphic:                               label.               (line  79)
-* graphical user interface:              GUI.                 (line   6)
-* gray:                                  Pens.                (line  25)
-* Grayscale:                             palette.             (line   9)
-* grayscale:                             Pens.                (line  25)
-* grid <1>:                              graph.               (line 733)
-* grid:                                  Pens.                (line 251)
-* grid3:                                 grid3.               (line   6)
-* gs:                                    Configuring.         (line   6)
-* gsl:                                   Mathematical functions.
-                                                              (line  48)
-* GSL:                                   Compiling from UNIX source.
-                                                              (line  57)
-* gsOptions:                             Options.             (line 131)
-* GUI:                                   GUI.                 (line   6)
-* GUI installation:                      GUI installation.    (line   6)
-* GUI usage:                             GUI usage.           (line   6)
-* guide:                                 Paths and guides.    (line 303)
-* guide3:                                three.               (line   6)
-* hatch:                                 Pens.                (line 267)
-* height:                                LaTeX usage.         (line  51)
-* help <1>:                              Debugger.            (line  30)
-* help <2>:                              Help.                (line   6)
-* help:                                  Interactive mode.    (line  44)
-* Hermite:                               graph.               (line  37)
-* Hermite(splinetype splinetype:         graph.               (line  37)
-* hex <1>:                               Pens.                (line  60)
-* hex:                                   Data types.          (line 283)
-* hexidecimal <1>:                       Pens.                (line  59)
-* hexidecimal:                           Data types.          (line 283)
-* hidden surface removal:                three.               (line 601)
-* histogram:                             Mathematical functions.
-                                                              (line  39)
-* history <1>:                           Interactive mode.    (line  59)
-* history:                               Files.               (line 142)
-* historylines:                          Interactive mode.    (line  64)
-* HookHead:                              draw.                (line  26)
-* HookHead3:                             three.               (line 560)
-* Horizontal:                            flowchart.           (line  81)
-* hyperrefOptions:                       Options.             (line 131)
-* hypot:                                 Mathematical functions.
-                                                              (line   6)
-* I:                                     Mathematical functions.
-                                                              (line  48)
-* i_scaled:                              Mathematical functions.
-                                                              (line  48)
-* iconic:                                three.               (line 222)
-* identity <1>:                          Arrays.              (line 300)
-* identity <2>:                          Mathematical functions.
-                                                              (line   6)
-* identity:                              Transforms.          (line  24)
-* identity4:                             three.               (line 449)
-* if:                                    Programming.         (line   8)
-* IgnoreAspect:                          Frames and pictures. (line  58)
-* image:                                 palette.             (line  34)
-* ImageMagick <1>:                       Options.             (line 144)
-* ImageMagick <2>:                       animation.           (line   6)
-* ImageMagick:                           Configuring.         (line  67)
-* images:                                palette.             (line   6)
-* implicit casts:                        Casts.               (line   6)
-* implicit linear solver:                MetaPost.            (line  10)
-* implicit scaling:                      Implicit scaling.    (line   6)
-* import:                                Import.              (line  46)
-* inches:                                Tutorial.            (line  63)
-* include:                               Import.              (line 127)
-* including images:                      label.               (line  79)
-* increasing:                            math.                (line  59)
-* inf:                                   Data types.          (line  33)
-* inheritance:                           Structures.          (line 181)
-* initialized:                           Arrays.              (line  39)
-* initializers:                          Variable initializers.
-                                                              (line   6)
-* inline:                                LaTeX usage.         (line  51)
-* InOutTicks:                            graph3.              (line  35)
-* input <1>:                             Interactive mode.    (line  48)
-* input:                                 Files.               (line  10)
-* insert <1>:                            Arrays.              (line  39)
-* insert:                                Data types.          (line 237)
-* inside:                                Paths and guides.    (line 282)
-* inst:                                  Debugger.            (line  36)
-* installation:                          Installation.        (line   6)
-* int:                                   Data types.          (line  28)
-* integer division:                      Arithmetic & logical.
-                                                              (line   6)
-* interactive mode:                      Interactive mode.    (line   6)
-* interior:                              Paths and guides.    (line 278)
-* international characters:              unicode.             (line   6)
-* interp:                                Arithmetic & logical.
-                                                              (line  76)
-* interpolate:                           interpolate.         (line   6)
-* intersect <1>:                         three.               (line 519)
-* intersect <2>:                         math.                (line  13)
-* intersect:                             Paths and guides.    (line 184)
-* intersectionpoint <1>:                 three.               (line 519)
-* intersectionpoint <2>:                 math.                (line  17)
-* intersectionpoint:                     Paths and guides.    (line 227)
-* intersectionpoints <1>:                three.               (line 519)
-* intersectionpoints:                    Paths and guides.    (line 231)
-* intersections <1>:                     three.               (line 519)
-* intersections:                         Paths and guides.    (line 195)
-* InTicks:                               graph3.              (line  35)
-* intMax:                                Data types.          (line  28)
-* intMin:                                Data types.          (line  28)
-* inverse <1>:                           Arrays.              (line 306)
-* inverse:                               Transforms.          (line  16)
-* invert:                                three.               (line 439)
-* invisible:                             Pens.                (line  39)
-* isnan:                                 Data types.          (line  33)
-* J:                                     Mathematical functions.
-                                                              (line   6)
-* Japanese:                              unicode.             (line  12)
-* K:                                     Mathematical functions.
-                                                              (line  48)
-* k_scaled:                              Mathematical functions.
-                                                              (line  48)
-* Kate:                                  Editing modes.       (line  49)
-* KDE editor:                            Editing modes.       (line  49)
-* keepAspect <1>:                        LaTeX usage.         (line  51)
-* keepAspect:                            Frames and pictures. (line  54)
-* keyboard bindings::                    three.               (line 181)
-* keys:                                  Arrays.              (line  39)
-* keyword:                               Named arguments.     (line  37)
-* keyword-only:                          Named arguments.     (line  37)
-* keywords:                              Named arguments.     (line   6)
-* Korean:                                unicode.             (line  12)
-* label:                                 three.               (line 483)
-* Label <1>:                             graph.               (line 343)
-* Label:                                 label.               (line  14)
-* label:                                 clip.                (line  16)
-* Label:                                 draw.                (line  98)
-* labelpath:                             labelpath.           (line   6)
-* labelpath3:                            labelpath3.          (line   6)
-* labelx:                                graph.               (line 343)
-* labely:                                graph.               (line 343)
-* Landscape:                             Frames and pictures. (line  95)
-* lastcut:                               Paths and guides.    (line 254)
-* lasy-mode:                             Editing modes.       (line   6)
-* latex:                                 Options.             (line 144)
-* LaTeX fonts:                           Pens.                (line 192)
-* LaTeX usage:                           LaTeX usage.         (line   6)
-* latexmk:                               LaTeX usage.         (line  30)
-* latin1:                                latin1.              (line   6)
-* latitude:                              Data types.          (line 136)
-* latticeshade:                          fill.                (line  32)
-* layer:                                 Drawing commands.    (line  16)
-* leastsquares <1>:                      graph.               (line 901)
-* leastsquares:                          stats.               (line   6)
-* Left:                                  graph.               (line 284)
-* LeftRight:                             graph.               (line 290)
-* LeftSide:                              label.               (line  61)
-* LeftTicks:                             graph.               (line 161)
-* LeftView:                              three.               (line 398)
-* legend <1>:                            graph.               (line 432)
-* legend <2>:                            draw.                (line  64)
-* legend:                                Drawing commands.    (line  31)
-* Legendre:                              Mathematical functions.
-                                                              (line  48)
-* length <1>:                            three.               (line 519)
-* length <2>:                            Arrays.              (line  39)
-* length <3>:                            Paths and guides.    (line  65)
-* length:                                Data types.          (line  62)
-* letter:                                Configuring.         (line  61)
-* lexorder:                              math.                (line  68)
-* libm routines:                         Mathematical functions.
-                                                              (line   6)
-* libsigsegv <1>:                        Help.                (line  33)
-* libsigsegv:                            Functions.           (line  88)
-* limits:                                graph.               (line 637)
-* line:                                  Arrays.              (line 344)
-* line mode:                             Arrays.              (line 344)
-* Linear:                                graph.               (line 682)
-* linecap:                               Pens.                (line 129)
-* linejoin:                              Pens.                (line 138)
-* lineskip:                              Pens.                (line 178)
-* linetype:                              Pens.                (line 115)
-* linewidth:                             Pens.                (line 119)
-* locale:                                Data types.          (line 293)
-* Log:                                   graph.               (line 682)
-* log:                                   Mathematical functions.
-                                                              (line   6)
-* log-log graph:                         graph.               (line 713)
-* log10:                                 Mathematical functions.
-                                                              (line   6)
-* log1p:                                 Mathematical functions.
-                                                              (line   6)
-* log2 graph:                            graph.               (line 762)
-* logarithmic graph:                     graph.               (line 713)
-* logical operators:                     Arithmetic & logical.
-                                                              (line   6)
-* longdashdotted:                        Pens.                (line  95)
-* longdashed:                            Pens.                (line  95)
-* longitude:                             Data types.          (line 141)
-* loop:                                  Programming.         (line   8)
-* MacOS X binary distributions:          MacOS X binary distributions.
-                                                              (line   6)
-* makepen:                               Pens.                (line 300)
-* map:                                   Arrays.              (line 141)
-* Margin:                                draw.                (line  42)
-* Margin3:                               three.               (line 576)
-* margins:                               three.               (line 274)
-* Margins:                               draw.                (line  42)
-* Margins3:                              three.               (line 576)
-* mark:                                  graph.               (line 485)
-* markangle:                             markers.             (line  38)
-* marker:                                graph.               (line 485)
-* markers:                               markers.             (line   6)
-* marknodes:                             graph.               (line 485)
-* markuniform:                           graph.               (line 485)
-* mask:                                  Data types.          (line  33)
-* math:                                  math.                (line   6)
-* mathematical functions:                Mathematical functions.
-                                                              (line   6)
-* max <1>:                               three.               (line 519)
-* max <2>:                               Arrays.              (line 225)
-* max <3>:                               Frames and pictures. (line   7)
-* max:                                   Paths and guides.    (line 267)
-* maxbound:                              Data types.          (line 106)
-* maxtile:                               three.               (line 222)
-* maxtimes:                              Paths and guides.    (line 222)
-* maxviewport:                           three.               (line 222)
-* MetaPost:                              MetaPost.            (line   6)
-* MetaPost ... :                         Bezier curves.       (line  70)
-* MetaPost cutafter:                     Paths and guides.    (line 255)
-* MetaPost cutbefore:                    Paths and guides.    (line 251)
-* MetaPost pickup:                       Pens.                (line   6)
-* MetaPost whatever:                     MetaPost.            (line  10)
-* Microsoft Windows:                     Microsoft Windows.   (line   6)
-* MidArcArrow:                           draw.                (line  26)
-* MidArcArrow3:                          three.               (line 560)
-* MidArrow:                              draw.                (line  26)
-* MidArrow3:                             three.               (line 560)
-* midpoint:                              Paths and guides.    (line 169)
-* MidPoint:                              label.               (line  56)
-* min <1>:                               three.               (line 519)
-* min <2>:                               Arrays.              (line 218)
-* min <3>:                               Frames and pictures. (line   7)
-* min:                                   Paths and guides.    (line 263)
-* minbound:                              Data types.          (line 103)
-* minipage:                              label.               (line 118)
-* mintimes:                              Paths and guides.    (line 217)
-* miterjoin:                             Pens.                (line 138)
-* miterlimit:                            Pens.                (line 147)
-* mktemp:                                Files.               (line  44)
-* mm:                                    Tutorial.            (line  63)
-* mode:                                  Files.               (line  75)
-* monotonic:                             graph.               (line  37)
-* mouse:                                 GUI.                 (line   6)
-* mouse bindings:                        three.               (line 149)
-* Move:                                  Pens.                (line 339)
-* MoveQuiet:                             Pens.                (line 345)
-* multisample:                           three.               (line 140)
-* N:                                     Tutorial.            (line 106)
-* name:                                  Files.               (line  88)
-* named arguments:                       Named arguments.     (line   6)
-* natural:                               graph.               (line  37)
-* new <1>:                               Arrays.              (line 109)
-* new:                                   Structures.          (line   6)
-* newframe:                              Frames and pictures. (line   7)
-* newl:                                  Files.               (line  61)
-* newton:                                Mathematical functions.
-                                                              (line  66)
-* next:                                  Debugger.            (line  42)
-* NFSS:                                  Pens.                (line 192)
-* nobasealign:                           Pens.                (line 168)
-* NoFill <1>:                            Frames and pictures. (line 141)
-* NoFill:                                draw.                (line  26)
-* NoMargin:                              draw.                (line  42)
-* NoMargin3:                             three.               (line 576)
-* none:                                  Files.               (line  61)
-* None:                                  draw.                (line  19)
-* normal:                                three.               (line 505)
-* nosafe:                                Options.             (line 164)
-* NOT:                                   Arithmetic & logical.
-                                                              (line  80)
-* notaknot:                              graph.               (line  37)
-* NoTicks:                               graph.               (line 161)
-* NoTicks3:                              graph3.              (line  35)
-* null:                                  Structures.          (line   6)
-* nullpen <1>:                           Frames and pictures. (line 127)
-* nullpen:                               label.               (line  14)
-* NURBS:                                 three.               (line 375)
-* O:                                     three.               (line 286)
-* obj:                                   obj.                 (line   9)
-* oblique:                               three.               (line 331)
-* obliqueX:                              three.               (line 339)
-* obliqueY:                              three.               (line 346)
-* obliqueZ:                              three.               (line 331)
-* ode:                                   ode.                 (line   9)
-* offset <1>:                            Options.             (line 169)
-* offset:                                Pens.                (line 115)
-* OmitTick:                              graph.               (line 239)
-* OmitTickInterval:                      graph.               (line 239)
-* OmitTickIntervals:                     graph.               (line 239)
-* opacity:                               Pens.                (line 222)
-* open:                                  Files.               (line  12)
-* OpenGL:                                three.               (line 140)
-* operator:                              User-defined operators.
-                                                              (line   6)
-* operator --:                           graph.               (line  31)
-* operator ..:                           graph.               (line  34)
-* operator answer:                       Interactive mode.    (line  37)
-* operator cast:                         Casts.               (line  30)
-* operator ecast:                        Casts.               (line  57)
-* operator init <1>:                     Structures.          (line 134)
-* operator init:                         Variable initializers.
-                                                              (line   6)
-* operators:                             Operators.           (line   6)
-* options:                               Options.             (line   6)
-* OR:                                    Arithmetic & logical.
-                                                              (line  80)
-* orientation:                           Frames and pictures. (line  95)
-* orthographic:                          three.               (line 350)
-* outformat:                             three.               (line 140)
-* outprefix:                             Frames and pictures. (line  83)
-* output <1>:                            Options.             (line 144)
-* output:                                Files.               (line  36)
-* OutTicks:                              graph3.              (line  35)
-* overloading functions:                 Functions.           (line  44)
-* overwrite:                             Pens.                (line 324)
-* P:                                     Mathematical functions.
-                                                              (line  48)
-* pack:                                  label.               (line 101)
-* packing:                               Rest arguments.      (line  30)
-* pair <1>:                              Data types.          (line  43)
-* pair:                                  Tutorial.            (line  51)
-* pairs:                                 Arrays.              (line 242)
-* paperheight:                           Configuring.         (line  61)
-* papertype:                             Configuring.         (line  61)
-* paperwidth:                            Configuring.         (line  61)
-* parallelogram:                         flowchart.           (line  50)
-* parametric surface:                    graph3.              (line 101)
-* parametrized curve:                    graph.               (line 637)
-* partialsum:                            math.                (line  53)
-* patch-dependent colors:                three.               (line  81)
-* path <1>:                              flowchart.           (line  81)
-* path <2>:                              three.               (line  43)
-* path:                                  Paths and guides.    (line   7)
-* path markers:                          graph.               (line 485)
-* path3:                                 three.               (line   6)
-* path[]:                                Tutorial.            (line 134)
-* patterns <1>:                          patterns.            (line   6)
-* patterns:                              Pens.                (line 238)
-* PDF:                                   Options.             (line 144)
-* pdflatex:                              Options.             (line 144)
-* pdfviewer:                             Configuring.         (line   6)
-* pdfviewerOptions:                      Options.             (line 131)
-* pen:                                   Pens.                (line   6)
-* PenMargin:                             draw.                (line  42)
-* PenMargin2:                            three.               (line 576)
-* PenMargin3:                            three.               (line 576)
-* PenMargins:                            draw.                (line  42)
-* PenMargins2:                           three.               (line 576)
-* PenMargins3:                           three.               (line 576)
-* periodic:                              graph.               (line  37)
-* perl:                                  LaTeX usage.         (line  30)
-* perpendicular:                         geometry.            (line   6)
-* perspective:                           three.               (line 375)
-* picture:                               Frames and pictures. (line  35)
-* picture alignment:                     Frames and pictures. (line 209)
-* piecewisestraight:                     Paths and guides.    (line  81)
-* pixel:                                 three.               (line 583)
-* Pl:                                    Mathematical functions.
-                                                              (line  48)
-* plain:                                 plain.               (line   6)
-* planar:                                three.               (line  89)
-* plane:                                 three.               (line 313)
-* planeproject:                          three.               (line 502)
-* point <1>:                             three.               (line 519)
-* point:                                 Paths and guides.    (line  84)
-* polar:                                 Data types.          (line 121)
-* polargraph:                            graph.               (line  90)
-* polygon:                               graph.               (line 485)
-* pop:                                   Arrays.              (line  39)
-* Portrait:                              Frames and pictures. (line  95)
-* postcontrol <1>:                       three.               (line 519)
-* postcontrol:                           Paths and guides.    (line 135)
-* postfix operators:                     Self & prefix operators.
-                                                              (line  19)
-* postscript:                            Frames and pictures. (line 271)
-* PostScript fonts:                      Pens.                (line 210)
-* PostScript subpath:                    Tutorial.            (line 134)
-* pow10:                                 Mathematical functions.
-                                                              (line   6)
-* prc:                                   three.               (line 243)
-* precision:                             Files.               (line  92)
-* precontrol <1>:                        three.               (line 519)
-* precontrol:                            Paths and guides.    (line 128)
-* prefix operators:                      Self & prefix operators.
-                                                              (line   6)
-* private:                               Structures.          (line   6)
-* programming:                           Programming.         (line   6)
-* pstoedit:                              PostScript to Asymptote.
-                                                              (line   6)
-* psview:                                Microsoft Windows.   (line  16)
-* psviewer:                              Configuring.         (line   6)
-* psviewerOptions:                       Options.             (line 131)
-* pt:                                    Tutorial.            (line  63)
-* public:                                Structures.          (line   6)
-* push:                                  Arrays.              (line  39)
-* Python usage:                          Interactive mode.    (line  80)
-* quadraticroots:                        Arrays.              (line 309)
-* quarticroots:                          math.                (line  22)
-* quick reference:                       Description.         (line  80)
-* quit <1>:                              Debugger.            (line  54)
-* quit <2>:                              Interactive mode.    (line  59)
-* quit:                                  Tutorial.            (line  37)
-* quote:                                 Import.              (line 116)
-* quotient:                              Arithmetic & logical.
-                                                              (line   6)
-* RadialShade:                           Frames and pictures. (line 159)
-* radialshade:                           fill.                (line  51)
-* RadialShadeDraw:                       Frames and pictures. (line 163)
-* radians:                               Mathematical functions.
-                                                              (line  17)
-* radius <1>:                            three.               (line 519)
-* radius:                                Paths and guides.    (line 124)
-* Rainbow:                               palette.             (line  12)
-* rand:                                  Mathematical functions.
-                                                              (line  39)
-* randMax:                               Mathematical functions.
-                                                              (line  39)
-* read:                                  Arrays.              (line 385)
-* reading:                               Files.               (line  12)
-* reading string arrays:                 Arrays.              (line 354)
-* readline:                              Files.               (line 134)
-* real:                                  Data types.          (line  33)
-* realDigits:                            Data types.          (line  33)
-* realEpsilon:                           Data types.          (line  33)
-* realMax:                               Data types.          (line  33)
-* realMin:                               Data types.          (line  33)
-* realmult:                              Data types.          (line  97)
-* rectangle:                             flowchart.           (line  37)
-* recursion:                             Functions.           (line  88)
-* reference:                             Description.         (line  80)
-* reflect:                               Transforms.          (line  51)
-* Relative:                              label.               (line  51)
-* relpoint:                              Paths and guides.    (line 165)
-* reltime:                               Paths and guides.    (line 161)
-* remainder:                             Mathematical functions.
-                                                              (line   6)
-* rename:                                Files.               (line 151)
-* render <1>:                            Options.             (line 144)
-* render:                                three.               (line  47)
-* replace:                               Data types.          (line 254)
-* resetdefaultpen:                       Pens.                (line 353)
-* rest arguments:                        Rest arguments.      (line   6)
-* restore:                               Frames and pictures. (line 265)
-* restricted:                            Structures.          (line   6)
-* return:                                Debugger.            (line  48)
-* reverse <1>:                           three.               (line 519)
-* reverse <2>:                           Arrays.              (line 146)
-* reverse <3>:                           Paths and guides.    (line 172)
-* reverse:                               Data types.          (line 250)
-* rewind:                                Files.               (line  92)
-* rfind:                                 Data types.          (line 231)
-* rgb:                                   Pens.                (line  30)
-* Riemann zeta function:                 Mathematical functions.
-                                                              (line  48)
-* Right:                                 graph.               (line 287)
-* RightSide:                             label.               (line  61)
-* RightTicks:                            graph.               (line 161)
-* RightView:                             three.               (line 398)
-* rotate:                                three.               (line 470)
-* Rotate:                                label.               (line  36)
-* Rotate(pair z):                        label.               (line  39)
-* round:                                 Mathematical functions.
-                                                              (line  26)
-* roundcap:                              Pens.                (line 129)
-* roundedpath:                           roundedpath.         (line   6)
-* roundjoin:                             Pens.                (line 138)
-* roundrectangle:                        flowchart.           (line  69)
-* RPM:                                   UNIX binary distributions.
-                                                              (line   6)
-* runtime imports:                       Import.              (line  98)
-* Russian:                               unicode.             (line   7)
-* S:                                     Tutorial.            (line 106)
-* safe:                                  Options.             (line 164)
-* save:                                  Frames and pictures. (line 262)
-* saveline:                              Files.               (line 134)
-* scale:                                 three.               (line 469)
-* Scale:                                 graph.               (line 698)
-* scale <1>:                             graph.               (line 682)
-* scale <2>:                             Transforms.          (line  39)
-* scale:                                 Pens.                (line 115)
-* Scale:                                 label.               (line  45)
-* scale3:                                three.               (line 466)
-* scaled graph:                          graph.               (line 663)
-* scientific graph:                      graph.               (line 397)
-* scroll:                                Files.               (line 108)
-* search:                                Arrays.              (line 164)
-* search paths:                          Search paths.        (line   6)
-* Seascape:                              Frames and pictures. (line 100)
-* secondary axis:                        graph.               (line 812)
-* secondaryX:                            graph.               (line 812)
-* secondaryY:                            graph.               (line 812)
-* seconds:                               Data types.          (line 306)
-* seek:                                  Files.               (line  92)
-* seekeof:                               Files.               (line  92)
-* segment:                               math.                (line  50)
-* segmentation fault:                    Help.                (line  33)
-* self operators:                        Self & prefix operators.
-                                                              (line   6)
-* sequence:                              Arrays.              (line 128)
-* settings <1>:                          Options.             (line 116)
-* settings:                              Configuring.         (line  23)
-* sgn:                                   Mathematical functions.
-                                                              (line  26)
-* shading:                               fill.                (line  32)
-* shift <1>:                             three.               (line 454)
-* shift:                                 Transforms.          (line  27)
-* Shift:                                 label.               (line  33)
-* shiftless:                             Transforms.          (line  53)
-* shipout:                               Frames and pictures. (line  83)
-* showtarget:                            three.               (line 350)
-* Si:                                    Mathematical functions.
-                                                              (line  48)
-* signedint:                             Files.               (line  75)
-* SimpleHead:                            draw.                (line  26)
-* simplex:                               simplex.             (line   6)
-* simpson:                               Mathematical functions.
-                                                              (line  82)
-* Sin:                                   Mathematical functions.
-                                                              (line  20)
-* sin:                                   Mathematical functions.
-                                                              (line   6)
-* single precision:                      Files.               (line  75)
-* singleint:                             Files.               (line  75)
-* singlereal:                            Files.               (line  75)
-* sinh:                                  Mathematical functions.
-                                                              (line   6)
-* SixViews:                              three.               (line 413)
-* SixViewsFR:                            three.               (line 413)
-* SixViewsUS:                            three.               (line 413)
-* size <1>:                              Options.             (line 144)
-* size <2>:                              three.               (line 519)
-* size <3>:                              Frames and pictures. (line  43)
-* size:                                  Paths and guides.    (line  70)
-* size3:                                 three.               (line 271)
-* slant:                                 Transforms.          (line  45)
-* Slant:                                 label.               (line  42)
-* sleep:                                 Data types.          (line 351)
-* slice:                                 Paths and guides.    (line 240)
-* slices:                                Slices.              (line   6)
-* slide:                                 slide.               (line   6)
-* slope:                                 math.                (line  44)
-* slopefield:                            slopefield.          (line   6)
-* sncndn:                                Mathematical functions.
-                                                              (line  48)
-* solid:                                 Pens.                (line  95)
-* solids:                                solids.              (line   9)
-* solve:                                 Arrays.              (line 278)
-* sort:                                  Arrays.              (line 184)
-* Spline <1>:                            graph3.              (line 101)
-* Spline:                                graph.               (line  34)
-* split:                                 Data types.          (line 263)
-* sqrt:                                  Mathematical functions.
-                                                              (line   6)
-* squarecap:                             Pens.                (line 129)
-* srand:                                 Mathematical functions.
-                                                              (line  39)
-* stack overflow <1>:                    Help.                (line  33)
-* stack overflow:                        Functions.           (line  88)
-* static:                                Static.              (line   6)
-* stats:                                 stats.               (line   6)
-* stdin:                                 Files.               (line  48)
-* stdout:                                Files.               (line  48)
-* step:                                  Debugger.            (line  39)
-* stickframe:                            markers.             (line  16)
-* stop:                                  Debugger.            (line  10)
-* straight:                              three.               (line 519)
-* Straight:                              graph.               (line  31)
-* straight:                              Paths and guides.    (line  77)
-* strftime:                              Data types.          (line 298)
-* string:                                Data types.          (line 181)
-* stroke:                                fill.                (line  36)
-* strokepath:                            Paths and guides.    (line 297)
-* strptime:                              Data types.          (line 306)
-* struct:                                Structures.          (line   6)
-* structures:                            Structures.          (line   6)
-* subpath <1>:                           three.               (line 519)
-* subpath:                               Paths and guides.    (line 175)
-* subpictures:                           Frames and pictures. (line 103)
-* substr:                                Data types.          (line 246)
-* Subversion:                            Subversion.          (line   6)
-* sum:                                   Arrays.              (line 213)
-* superpath:                             Tutorial.            (line 134)
-* Suppress:                              Pens.                (line 331)
-* SuppressQuiet:                         Pens.                (line 335)
-* surface <1>:                           graph3.              (line 101)
-* surface:                               three.               (line  47)
-* SVG:                                   Options.             (line 144)
-* SVN:                                   Subversion.          (line   6)
-* system <1>:                            Options.             (line 164)
-* system:                                Data types.          (line 328)
-* syzygy:                                syzygy.              (line   6)
-* tab:                                   Files.               (line  61)
-* tab completion:                        Tutorial.            (line  37)
-* Tan:                                   Mathematical functions.
-                                                              (line  20)
-* tan:                                   Mathematical functions.
-                                                              (line   6)
-* tanh:                                  Mathematical functions.
-                                                              (line   6)
-* target:                                three.               (line 350)
-* tell:                                  Files.               (line  92)
-* tension <1>:                           three.               (line   6)
-* tension:                               Bezier curves.       (line  56)
-* tensionSpecifier:                      Paths and guides.    (line 388)
-* tensor product shading:                fill.                (line  78)
-* tensorshade:                           fill.                (line  78)
-* tessellation:                          three.               (line 112)
-* tex <1>:                               Options.             (line 144)
-* tex:                                   Frames and pictures. (line 278)
-* TeX fonts:                             Pens.                (line 201)
-* TeX string:                            Data types.          (line 181)
-* texcommand:                            Configuring.         (line  67)
-* TeXHead:                               draw.                (line  26)
-* TeXHead3:                              three.               (line 560)
-* texpath <1>:                           label.               (line 115)
-* texpath:                               Configuring.         (line  67)
-* texpreamble:                           Frames and pictures. (line 286)
-* texreset:                              Frames and pictures. (line 289)
-* textbook graph:                        graph.               (line 372)
-* tgz:                                   UNIX binary distributions.
-                                                              (line   6)
-* thick:                                 three.               (line 123)
-* thin:                                  three.               (line 123)
-* this:                                  Structures.          (line   6)
-* three:                                 three.               (line   6)
-* ThreeViews:                            three.               (line 413)
-* ThreeViewsFR:                          three.               (line 413)
-* ThreeViewsUS:                          three.               (line 413)
-* tick:                                  graph.               (line 343)
-* Ticks:                                 graph.               (line 161)
-* ticks:                                 graph.               (line 161)
-* tildeframe:                            markers.             (line  26)
-* tile:                                  Pens.                (line 251)
-* tilings:                               Pens.                (line 238)
-* time <1>:                              math.                (line  30)
-* time:                                  Data types.          (line 298)
-* times:                                 Paths and guides.    (line 209)
-* Top:                                   graph.               (line 137)
-* TopView:                               three.               (line 398)
-* trace:                                 Debugger.            (line  51)
-* trailingzero:                          graph.               (line 175)
-* transform <1>:                         three.               (line 494)
-* transform:                             Transforms.          (line   6)
-* transform3:                            three.               (line 449)
-* transparency:                          Pens.                (line 222)
-* transpose:                             Arrays.              (line 205)
-* tree:                                  tree.                (line   9)
-* trembling:                             trembling.           (line   6)
-* triangle:                              geometry.            (line   6)
-* triangles:                             three.               (line 112)
-* triangulate:                           contour.             (line 156)
-* tridiagonal:                           Arrays.              (line 266)
-* trigonometric integrals:               Mathematical functions.
-                                                              (line  48)
-* triple:                                Data types.          (line 110)
-* TrueMargin:                            draw.                (line  42)
-* TrueMargin3:                           three.               (line 576)
-* tube <1>:                              tube.                (line   6)
-* tube:                                  three.               (line 123)
-* tutorial:                              Tutorial.            (line   6)
-* type1cm:                               Pens.                (line 178)
-* typedef <1>:                           Functions.           (line  36)
-* typedef:                               Data types.          (line 361)
-* U3D:                                   embed.               (line  24)
-* undefined:                             Paths and guides.    (line 271)
-* UnFill:                                Frames and pictures. (line 152)
-* unfill:                                fill.                (line 110)
-* UnFill:                                draw.                (line  26)
-* unicode:                               unicode.             (line   6)
-* uniform:                               Arrays.              (line 155)
-* Uninstall:                             Uninstall.           (line   6)
-* unique:                                math.                (line  64)
-* unit:                                  Data types.          (line  80)
-* unitbox <1>:                           three.               (line 319)
-* unitbox:                               Tutorial.            (line 155)
-* unitcircle <1>:                        three.               (line 286)
-* unitcircle:                            Tutorial.            (line 128)
-* unitrand:                              Mathematical functions.
-                                                              (line  39)
-* unitsize <1>:                          Frames and pictures. (line  64)
-* unitsize:                              Tutorial.            (line  86)
-* UNIX binary distributions:             UNIX binary distributions.
-                                                              (line   6)
-* unpacking:                             Rest arguments.      (line  39)
-* unravel:                               Import.              (line  30)
-* up:                                    three.               (line 350)
-* update:                                Files.               (line  36)
-* UpsideDown:                            Frames and pictures. (line  95)
-* usepackage:                            Frames and pictures. (line 291)
-* user coordinates:                      Tutorial.            (line  86)
-* user-defined operators:                User-defined operators.
-                                                              (line   6)
-* usleep:                                Data types.          (line 354)
-* value:                                 math.                (line  38)
-* var:                                   Variable initializers.
-                                                              (line  63)
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-* vectorization:                         Arrays.              (line 323)
-* verbatim:                              Frames and pictures. (line 271)
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-* Vertical:                              flowchart.           (line  81)
-* viewportheight:                        LaTeX usage.         (line  51)
-* viewportmargin:                        three.               (line 274)
-* viewportsize:                          three.               (line 274)
-* viewportwidth:                         LaTeX usage.         (line  51)
-* views:                                 three.               (line 243)
-* vim:                                   Editing modes.       (line  33)
-* virtual functions:                     Structures.          (line 181)
-* void:                                  Data types.          (line  10)
-* W:                                     Tutorial.            (line 106)
-* whatever:                              Paths and guides.    (line 235)
-* Wheel:                                 palette.             (line  22)
-* wheel mouse:                           GUI.                 (line   6)
-* while:                                 Programming.         (line  29)
-* white-space string delimiter mode:     Arrays.              (line 354)
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-* word:                                  Arrays.              (line 354)
-* write <1>:                             Arrays.              (line 394)
-* write:                                 Files.               (line  53)
-* X:                                     three.               (line 286)
-* xasy:                                  GUI.                 (line   6)
-* xaxis3:                                graph3.              (line   7)
-* xdr:                                   Files.               (line  75)
-* xelatex:                               Options.             (line 144)
-* xequals:                               graph.               (line 294)
-* XEquals:                               graph.               (line 280)
-* xlimits:                               graph.               (line 637)
-* XOR:                                   Arithmetic & logical.
-                                                              (line  80)
-* xpart:                                 Data types.          (line  91)
-* xscale:                                Transforms.          (line  33)
-* xscale3:                               three.               (line 457)
-* xtick:                                 graph.               (line 343)
-* XY:                                    three.               (line 479)
-* XYEquals:                              graph3.              (line  21)
-* XYZero:                                graph3.              (line  21)
-* XZEquals:                              graph3.              (line  21)
-* XZero:                                 graph.               (line 275)
-* XZZero:                                graph3.              (line  21)
-* Y <1>:                                 three.               (line 286)
-* Y:                                     Mathematical functions.
-                                                              (line   6)
-* yaxis3:                                graph3.              (line   7)
-* yequals:                               graph.               (line 294)
-* YEquals:                               graph.               (line 130)
-* ylimits:                               graph.               (line 637)
-* ypart:                                 Data types.          (line  94)
-* yscale:                                Transforms.          (line  36)
-* yscale3:                               three.               (line 460)
-* ytick:                                 graph.               (line 343)
-* YX:                                    three.               (line 494)
-* YZ:                                    three.               (line 494)
-* YZEquals:                              graph3.              (line  21)
-* YZero:                                 graph.               (line 125)
-* YZZero:                                graph3.              (line  21)
-* Z:                                     three.               (line 286)
-* zaxis3:                                graph3.              (line   7)
-* zero_Ai:                               Mathematical functions.
-                                                              (line  48)
-* zero_Ai_deriv:                         Mathematical functions.
-                                                              (line  48)
-* zero_Bi:                               Mathematical functions.
-                                                              (line  48)
-* zero_Bi_deriv:                         Mathematical functions.
-                                                              (line  48)
-* zero_J:                                Mathematical functions.
-                                                              (line  48)
-* zerowinding:                           Pens.                (line 152)
-* zeta:                                  Mathematical functions.
-                                                              (line  48)
-* zpart:                                 Data types.          (line 163)
-* zscale3:                               three.               (line 463)
-* ZX:                                    three.               (line 494)
-* ZY:                                    three.               (line 494)
-* |:                                     Arithmetic & logical.
-                                                              (line  62)
-* ||:                                    Arithmetic & logical.
-                                                              (line  59)
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