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+% Copyright 2019 by Till Tantau
+%
+% This file may be distributed and/or modified
+%
+% 1. under the LaTeX Project Public License and/or
+% 2. under the GNU Free Documentation License.
+%
+% See the file doc/generic/pgf/licenses/LICENSE for more details.
+
+
+\section{Plots of Functions}
+\label{section-tikz-plots}
+
+A warning before we get started: \emph{If you are looking for an easy way to
+create a normal plot of a function with scientific axes, ignore this section
+and instead look at the |pgfplots| package or at the |datavisualization|
+command from Part~\ref{part-dv}.}
+
+
+\subsection{Overview}
+\label{section-why-pgname-for-plots}
+
+\tikzname\ can be used to create plots of functions, a job that is normally
+handled by powerful programs like \textsc{gnuplot} or \textsc{mathematica}.
+These programs can produce two different kinds of output: First, they can
+output a complete plot picture in a certain format (like \pdf) that includes
+all low-level commands necessary for drawing the complete plot (including axes
+and labels). Second, they can usually also produce ``just plain data'' in the
+form of a long list of coordinates. Most of the powerful programs consider it a
+to be ``a bit boring'' to just output tabled data and very much prefer to
+produce fancy pictures. Nevertheless, when coaxed, they can also provide the
+plain data.
+
+The advantage of creating plots directly using \tikzname\ is
+\emph{consistency:} Plots created using \tikzname\ will automatically have the
+same styling and fonts as those used in the rest of a document -- something
+that is hard to do right when an external program gets involved. Other problems
+people encounter with external programs include: Formulas will look different,
+if they can be rendered at all; line widths will usually be too thick or too
+thin; scaling effects upon inclusion can create a mismatch between sizes in the
+plot and sizes in the text; the automatic grid generated by most programs is
+mostly distracting; the automatic ticks generated by most programs are cryptic
+numerics (try adding a tick reading ``$\pi$'' at the right point); most
+programs make it very easy to create ``chart junk'' in a most convenient
+fashion; arrows and plot marks will almost never match the arrows used in the
+rest of the document. This list is not exhaustive, unfortunately.
+
+There are basically three ways of creating plots using \tikzname:
+%
+\begin{enumerate}
+ \item Use the |plot| path operation. How this works is explained in the
+ present section. This is the most ``basic'' of the three options and
+ forces you to do a lot of things ``by hand'' like adding axes or ticks.
+ \item Use the |datavisualization| path command, which is documented in
+ Part~\ref{part-dv}. This command is much more powerful than the |plot|
+ path operation and produces complete plots including axes and ticks.
+ The downside is that you cannot use it to ``just'' quickly plot a
+ simple curve (or, more precisely, it is hard to use it in this way).
+ \item Use the |pgfplots| package, which is basically an alternative to the
+ |datavisualization| command. While the underlying philosophy of this
+ package is not as ``ambitious'' as that of the command
+ |datavisualization|, it is somewhat more mature, has a simpler design,
+ and wider support base.
+\end{enumerate}
+
+
+\subsection{The Plot Path Operation}
+
+The |plot| path operation can be used to append a line or curve to the path
+that goes through a large number of coordinates. These coordinates are either
+given in a simple list of coordinates, read from some file, or they are
+computed on the fly.
+
+The syntax of the |plot| comes in different versions.
+
+\begin{pathoperation}{--plot}{\meta{further arguments}}
+ This operation plots the curve through the coordinates specified in the
+ \meta{further arguments}. The current (sub)path is simply continued, that
+ is, a line-to operation to the first point of the curve is implicitly
+ added. The details of the \meta{further arguments} will be explained in a
+ moment.
+\end{pathoperation}
+
+\begin{pathoperation}{plot}{\meta{further arguments}}
+ This operation plots the curve through the coordinates specified in the
+ \meta{further arguments} by first ``moving'' to the first coordinate of the
+ curve.
+\end{pathoperation}
+
+The \meta{further arguments} are used in different ways to specifying the
+coordinates of the points to be plotted:
+%
+\begin{enumerate}
+ \item \opt{|--|}|plot|\oarg{local
+ options}\declare{|coordinates{|\meta{coordinate 1}\meta{coordinate
+ 2}\dots\meta{coordinate $n$}|}|}
+ \item \opt{|--|}|plot|\oarg{local
+ options}\declare{|file{|\meta{filename}|}|}
+ \item \opt{|--|}|plot|\oarg{local options}\declare{\meta{coordinate
+ expression}}
+ \item \opt{|--|}|plot|\oarg{local options}\declare{|function{|\meta{gnuplot
+ formula}|}|}
+\end{enumerate}
+
+These different ways are explained in the following.
+
+
+\subsection{Plotting Points Given Inline}
+
+Points can be given directly in the \TeX-file as in the following example:
+%
+\begin{codeexample}[]
+\tikz \draw plot coordinates {(0,0) (1,1) (2,0) (3,1) (2,1) (10:2cm)};
+\end{codeexample}
+
+Here is an example showing the difference between |plot| and |--plot|:
+%
+\begin{codeexample}[]
+\begin{tikzpicture}
+ \draw (0,0) -- (1,1) plot coordinates {(2,0) (4,0)};
+ \draw[color=red,xshift=5cm]
+ (0,0) -- (1,1) -- plot coordinates {(2,0) (4,0)};
+\end{tikzpicture}
+\end{codeexample}
+
+
+\subsection{Plotting Points Read From an External File}
+
+The second way of specifying points is to put them in an external file named
+\meta{filename}. Currently, the only file format that \tikzname\ allows is the
+following: Each line of the \meta{filename} should contain one line starting
+with two numbers, separated by a space. A line may also be empty or, if it
+starts with |#| or |%| it is considered empty. For such lines, a ``new data
+set'' is started, typically resulting in a new subpath being started in the
+plot (see Section~\ref{section-plot-jumps} on how to change this behavior, if
+necessary). For lines containing two numbers, they must be separated by a
+space. They may be following by arbitrary text, which is ignored, \emph{except}
+if it is |o| or |u|. In the first case, the point is considered to be an
+\emph{outlier} and normally also results in a new subpath being started. In the
+second case, the point is considered to be \emph{undefined}, which also results
+in a new subpath being started. Again, see Section~\ref{section-plot-jumps} on
+how to change this, if necessary. (This is exactly the format that
+\textsc{gnuplot} produces when you say |set table|.)
+%
+\begin{codeexample}[]
+\tikz \draw plot[mark=x,smooth] file {plots/pgfmanual-sine.table};
+\end{codeexample}
+
+The file |plots/pgfmanual-sine.table| reads:
+%
+\begin{codeexample}[code only]
+#Curve 0, 20 points
+#x y type
+0.00000 0.00000 i
+0.52632 0.50235 i
+1.05263 0.86873 i
+1.57895 0.99997 i
+...
+9.47368 -0.04889 i
+10.00000 -0.54402 i
+\end{codeexample}
+%
+It was produced from the following source, using |gnuplot|:
+%
+\begin{codeexample}[code only]
+set table "../plots/pgfmanual-sine.table"
+set format "%.5f"
+set samples 20
+plot [x=0:10] sin(x)
+\end{codeexample}
+
+The \meta{local options} of the |plot| operation are local to each plot and do
+not affect other plots ``on the same path''. For example, |plot[yshift=1cm]|
+will locally shift the plot 1cm upward. Remember, however, that most options
+can only be applied to paths as a whole. For example, |plot[red]| does not have
+the effect of making the plot red. After all, you are trying to ``locally''
+make part of the path red, which is not possible.
+
+
+\subsection{Plotting a Function}
+\label{section-tikz-plot}
+
+When you plot a function, the coordinates of the plot data can be computed by
+evaluating a mathematical expression. Since \pgfname\ comes with a mathematical
+engine, you can specify this expression and then have \tikzname\ produce the
+desired coordinates for you, automatically.
+
+Since this case is quite common when plotting a function, the syntax is easy:
+Following the |plot| command and its local options, you directly provide a
+\meta{coordinate expression}. It looks like a normal coordinate, but inside you
+may use a special macro, which is |\x| by default, but this can be changed
+using the |variable| option. The \meta{coordinate expression} is then evaluated
+for different values for |\x| and the resulting coordinates are plotted.
+
+Note that you will often have to put the $x$- or $y$-coordinate inside braces,
+namely whenever you use an expression involving a parenthesis.
+
+The following options influence how the \meta{coordinate expression} is
+evaluated:
+%
+\begin{key}{/tikz/variable=\meta{macro} (initially \string\x)}
+ Sets the macro whose value is set to the different values when
+ \meta{coordinate expression} is evaluated.
+\end{key}
+
+\begin{key}{/tikz/samples=\meta{number} (initially 25)}
+ Sets the number of samples used in the plot.
+\end{key}
+
+\begin{key}{/tikz/domain=\meta{start}|:|\meta{end} (initially -5:5)}
+ Sets the domain from which the samples are taken.
+\end{key}
+
+\begin{key}{/tikz/samples at=\meta{sample list}}
+ This option specifies a list of positions for which the variable should be
+ evaluated. For instance, you can say |samples at={1,2,8,9,10}| to have the
+ variable evaluated exactly for values $1$, $2$, $8$, $9$, and $10$. You can
+ use the |\foreach| syntax, so you can use |...| inside the \meta{sample
+ list}.
+
+ When this option is used, the |samples| and |domain| option are overruled.
+ The other way round, setting either |samples| or |domain| will overrule
+ this option.
+\end{key}
+%
+\begin{codeexample}[]
+\begin{tikzpicture}[domain=0:4]
+ \draw[very thin,color=gray] (-0.1,-1.1) grid (3.9,3.9);
+
+ \draw[->] (-0.2,0) -- (4.2,0) node[right] {$x$};
+ \draw[->] (0,-1.2) -- (0,4.2) node[above] {$f(x)$};
+
+ \draw[color=red] plot (\x,\x) node[right] {$f(x) =x$};
+ % \x r means to convert '\x' from degrees to _r_adians:
+ \draw[color=blue] plot (\x,{sin(\x r)}) node[right] {$f(x) = \sin x$};
+ \draw[color=orange] plot (\x,{0.05*exp(\x)}) node[right] {$f(x) = \frac{1}{20} \mathrm e^x$};
+\end{tikzpicture}
+\end{codeexample}
+
+\begin{codeexample}[]
+\tikz \draw[scale=0.5,domain=-3.141:3.141,smooth,variable=\t]
+ plot ({\t*sin(\t r)},{\t*cos(\t r)});
+\end{codeexample}
+
+\begin{codeexample}[]
+\tikz \draw[domain=0:360,smooth,variable=\t]
+ plot ({sin(\t)},\t/360,{cos(\t)});
+\end{codeexample}
+
+
+\subsection{Plotting a Function Using Gnuplot}
+\label{section-tikz-gnuplot}
+
+Often, you will want to plot points that are given via a function like $f(x) =
+x \sin x$. Unfortunately, \TeX\ does not really have enough computational power
+to generate the points of such a function efficiently (it is a text processing
+program, after all). However, if you allow it, \TeX\ can try to call external
+programs that can easily produce the necessary points. Currently, \tikzname\
+knows how to call \textsc{gnuplot}.
+
+When \tikzname\ encounters your operation
+|plot[id=|\meta{id}|] function{x*sin(x)}| for the first time, it will create a
+file called \meta{prefix}\meta{id}|.gnuplot|, where \meta{prefix} is
+|\jobname.| by default, that is, the name of your main |.tex| file. If no
+\meta{id} is given, it will be empty, which is alright, but it is better when
+each plot has a unique \meta{id} for reasons explained in a moment. Next,
+\tikzname\ writes some initialization code into this file followed by
+|plot x*sin(x)|. The initialization code sets up things such that the |plot|
+operation will write the coordinates into another file called
+\meta{prefix}\meta{id}|.table|. Finally, this table file is read as if you had
+said |plot file{|\meta{prefix}\meta{id}|.table}|.
+
+For the plotting mechanism to work, two conditions must be met:
+%
+\begin{enumerate}
+ \item You must have allowed \TeX\ to call external programs. This is often
+ switched off by default since this is a security risk (you might,
+ without knowing, run a \TeX\ file that calls all sorts of ``bad''
+ commands). To enable this ``calling external programs'' a command line
+ option must be given to the \TeX\ program. Usually, it is called
+ something like |shell-escape| or |enable-write18|. For example, for my
+ |pdflatex| the option |--shell-escape| can be given.
+ \item You must have installed the |gnuplot| program and \TeX\ must find it
+ when compiling your file.
+\end{enumerate}
+
+Unfortunately, these conditions will not always be met. Especially if you pass
+some source to a coauthor and the coauthor does not have \textsc{gnuplot}
+installed, he or she will have trouble compiling your files.
+
+For this reason, \tikzname\ behaves differently when you compile your graphic
+for the second time: If upon reaching |plot[id=|\meta{id}|] function{...}| the
+file \meta{prefix}\meta{id}|.table| already exists \emph{and} if the
+\meta{prefix}\meta{id}|.gnuplot| file contains what \tikzname\ thinks that it
+``should'' contain, the |.table| file is immediately read without trying to
+call a |gnuplot| program. This approach has the following advantages:
+%
+\begin{enumerate}
+ \item If you pass a bundle of your |.tex| file and all |.gnuplot| and
+ |.table| files to someone else, that person can \TeX\ the |.tex| file
+ without having to have |gnuplot| installed.
+ \item If the |\write18| feature is switched off for security reasons (a
+ good idea), then, upon the first compilation of the |.tex| file, the
+ |.gnuplot| will still be generated, but not the |.table| file. You can
+ then simply call |gnuplot| ``by hand'' for each |.gnuplot| file, which
+ will produce all necessary |.table| files.
+ \item If you change the function that you wish to plot or its domain,
+ \tikzname\ will automatically try to regenerate the |.table| file.
+ \item If, out of laziness, you do not provide an |id|, the same |.gnuplot|
+ will be used for different plots, but this is not a problem since the
+ |.table| will automatically be regenerated for each plot on-the-fly.
+ \emph{Note: If you intend to share your files with someone else, always
+ use an id, so that the file can by typeset without having
+ \textsc{gnuplot} installed.} Also, having unique ids for each plot will
+ improve compilation speed since no external programs need to be called,
+ unless it is really necessary.
+\end{enumerate}
+
+When you use |plot function{|\meta{gnuplot formula}|}|, the \meta{gnuplot
+formula} must be given in the |gnuplot| syntax, whose details are beyond the
+scope of this manual. Here is the ultra-condensed essence: Use |x| as the
+variable and use the C-syntax for normal plots, use |t| as the variable for
+parametric plots. Here are some examples:
+%
+\begin{codeexample}[]
+\begin{tikzpicture}[domain=0:4]
+ \draw[very thin,color=gray] (-0.1,-1.1) grid (3.9,3.9);
+
+ \draw[->] (-0.2,0) -- (4.2,0) node[right] {$x$};
+ \draw[->] (0,-1.2) -- (0,4.2) node[above] {$f(x)$};
+
+ \draw[color=red] plot[id=x] function{x} node[right] {$f(x) =x$};
+ \draw[color=blue] plot[id=sin] function{sin(x)} node[right] {$f(x) = \sin x$};
+ \draw[color=orange] plot[id=exp] function{0.05*exp(x)} node[right] {$f(x) = \frac{1}{20} \mathrm e^x$};
+\end{tikzpicture}
+\end{codeexample}
+
+The plot is influenced by the following options: First, the options |samples|
+and |domain| explained earlier. Second, there are some more specialized
+options.
+
+\begin{key}{/tikz/parametric=\meta{boolean} (default true)}
+ Sets whether the plot is a parametric plot. If true, then |t| must be used
+ instead of |x| as the parameter and two comma-separated functions must be
+ given in the \meta{gnuplot formula}. An example is the following:
+ %
+\begin{codeexample}[]
+\tikz \draw[scale=0.5,domain=-3.141:3.141,smooth]
+ plot[parametric,id=parametric-example] function{t*sin(t),t*cos(t)};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/range=\meta{start}|:|\meta{end}}
+ This key sets the range of the plot. If set, all points whose
+ $y$-coordinates lie outside this range will be considered to be outliers
+ and will cause jumps in the plot, by default:
+ %
+\begin{codeexample}[]
+\tikz \draw[scale=0.5,domain=-3.141:3.141, samples=100, smooth, range=-3:3]
+ plot[id=tan-example] function{tan(x)};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/yrange=\meta{start}|:|\meta{end}}
+ Same as |range|.
+\end{key}
+
+\begin{key}{/tikz/xrange=\meta{start}|:|\meta{end}}
+ Set the $x$-range. This makes sense only for parametric plots.
+ %
+\begin{codeexample}[]
+\tikz \draw[scale=0.5,domain=-3.141:3.141,smooth,xrange=0:1]
+ plot[parametric,id=parametric-example-cut] function{t*sin(t),t*cos(t)};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/id=\meta{id}}
+ Sets the identifier of the current plot. This should be a unique identifier
+ for each plot (though things will also work if it is not, but not as well,
+ see the explanations above). The \meta{id} will be part of a filename, so
+ it should not contain anything fancy like |*| or |$|.%$
+\end{key}
+
+\begin{key}{/tikz/prefix=\meta{prefix}}
+ The \meta{prefix} is put before each plot file name. The default is
+ |\jobname.|, but if you have many plots, it might be better to use, say
+ |plots/| and have all plots placed in a directory. You have to create the
+ directory yourself.
+\end{key}
+
+\begin{key}{/tikz/raw gnuplot}
+ This key causes the \meta{gnuplot formula} to be passed on to
+ \textsc{gnuplot} without setting up the samples or the |plot| operation.
+ Thus, you could write
+ %
+\begin{codeexample}[code only]
+plot[raw gnuplot,id=raw-example] function{set samples 25; plot sin(x)}
+\end{codeexample}
+ %
+ This can be useful for complicated things that need to be passed to
+ \textsc{gnuplot}. However, for really complicated situations you should
+ create a special external generating \textsc{gnuplot} file and use the
+ |file|-syntax to include the table ``by hand''.
+\end{key}
+
+The following styles influence the plot:
+%
+\begin{stylekey}{/tikz/every plot (initially \normalfont empty)}
+ This style is installed in each plot, that is, as if you always said
+ %
+\begin{codeexample}[code only]
+ plot[every plot,...]
+\end{codeexample}
+ %
+ This is most useful for globally setting a prefix for all plots by saying:
+ %
+\begin{codeexample}[code only]
+\tikzset{every plot/.style={prefix=plots/}}
+\end{codeexample}
+ %
+\end{stylekey}
+
+
+\subsection{Placing Marks on the Plot}
+
+As we saw already, it is possible to add \emph{marks} to a plot using the
+|mark| option. When this option is used, a copy of the plot mark is placed on
+each point of the plot. Note that the marks are placed \emph{after} the whole
+path has been drawn/filled/shaded. In this respect, they are handled like text
+nodes.
+
+In detail, the following options govern how marks are drawn:
+%
+\begin{key}{/tikz/mark=\meta{mark mnemonic}}
+ Sets the mark to a mnemonic that has previously been defined using the
+ |\pgfdeclareplotmark|. By default, |*|, |+|, and |x| are available, which
+ draw a filled circle, a plus, and a cross as marks. Many more marks become
+ available when the library |plotmarks| is loaded.
+ Section~\ref{section-plot-marks} lists the available plot marks.
+
+ One plot mark is special: the |ball| plot mark is available only in
+ \tikzname. The |ball color| option determines the balls's color. Do not use
+ this option with a large number of marks since it will take very long to
+ render in PostScript.
+
+ \begin{tabular}{lc}
+ Option & Effect \\
+ \hline
+ \vrule height14pt width0pt \plotmarkentrytikz{ball}
+ \end{tabular}
+\end{key}
+
+\begin{key}{/tikz/mark repeat=\meta{r}}
+ This option tells \tikzname\ that only every $r$th mark should be drawn.
+ %
+\begin{codeexample}[]
+\tikz \draw plot[mark=x,mark repeat=3,smooth] file {plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/mark phase=\meta{p}}
+ This option tells \tikzname\ that the first mark to be draw should be the
+ $p$th, followed by the $(p+r)$th, then the $(p+2r)$th, and so on.
+ %
+\begin{codeexample}[]
+\tikz \draw plot[mark=x,mark repeat=3,mark phase=6,smooth] file {plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/mark indices=\meta{list}}
+ This option allows you to specify explicitly the indices at which a mark
+ should be placed. Counting starts with 1. You can use the |\foreach|
+ syntax, that is, |...| can be used.
+ %
+\begin{codeexample}[]
+\tikz \draw plot[mark=x,mark indices={1,4,...,10,11,12,...,16,20},smooth]
+ file {plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/mark size=\meta{dimension}}
+ Sets the size of the plot marks. For circular plot marks, \meta{dimension}
+ is the radius, for other plot marks \meta{dimension} should be about half
+ the width and height.
+
+ This option is not really necessary, since you achieve the same effect by
+ specifying |scale=|\meta{factor} as a local option, where \meta{factor} is
+ the quotient of the desired size and the default size. However, using
+ |mark size| is a bit faster and more natural.
+\end{key}
+
+\begin{stylekey}{/tikz/every mark}
+ This style is installed before drawing plot marks. For example, you can
+ scale (or otherwise transform) the plot mark or set its color.
+\end{stylekey}
+
+\begin{key}{/tikz/mark options=\meta{options}}
+ Redefines |every mark| such that it sets \marg{options}.
+ %
+\begin{codeexample}[]
+\tikz \fill[fill=blue!20]
+ plot[mark=triangle*,mark options={color=blue,rotate=180}]
+ file{plots/pgfmanual-sine.table} |- (0,0);
+\end{codeexample}
+ %
+\end{key}
+
+\begin{stylekey}{/tikz/no marks}
+ Disables markers (the same as |mark=none|).
+\end{stylekey}
+%
+\begin{stylekey}{/tikz/no markers}
+ Disables markers (the same as |mark=none|).
+\end{stylekey}
+
+
+\subsection{Smooth Plots, Sharp Plots, Jump Plots, Comb Plots and Bar Plots}
+
+There are different things the |plot| operation can do with the points it reads
+from a file or from the inlined list of points. By default, it will connect
+these points by straight lines. However, you can also use options to change the
+behavior of |plot|.
+
+\begin{key}{/tikz/sharp plot}
+ This is the default and causes the points to be connected by straight
+ lines. This option is included only so that you can ``switch back'' if you
+ ``globally'' install, say, |smooth|.
+\end{key}
+
+\begin{key}{/tikz/smooth}
+ This option causes the points on the path to be connected using a smooth
+ curve:
+ %
+\begin{codeexample}[]
+\tikz\draw plot[smooth] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+
+ Note that the smoothing algorithm is not very intelligent. You will get the
+ best results if the bending angles are small, that is, less than about
+ $30^\circ$ and, even more importantly, if the distances between points are
+ about the same all over the plotting path.
+\end{key}
+
+\begin{key}{/tikz/tension=\meta{value}}
+ This option influences how ``tight'' the smoothing is. A lower value will
+ result in sharper corners, a higher value in more ``round'' curves. A value
+ of $1$ results in a circle if four points at quarter-positions on a circle
+ are given. The default is $0.55$. The ``correct'' value depends on the
+ details of plot.
+ %
+\begin{codeexample}[]
+\begin{tikzpicture}[smooth cycle]
+ \draw plot[tension=0.2]
+ coordinates{(0,0) (1,1) (2,0) (1,-1)};
+ \draw[yshift=-2.25cm] plot[tension=0.5]
+ coordinates{(0,0) (1,1) (2,0) (1,-1)};
+ \draw[yshift=-4.5cm] plot[tension=1]
+ coordinates{(0,0) (1,1) (2,0) (1,-1)};
+\end{tikzpicture}
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/smooth cycle}
+ This option causes the points on the path to be connected using a closed
+ smooth curve.
+ %
+\begin{codeexample}[]
+\tikz[scale=0.5]
+ \draw plot[smooth cycle] coordinates{(0,0) (1,0) (2,1) (1,2)}
+ plot coordinates{(0,0) (1,0) (2,1) (1,2)} -- cycle;
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/const plot}
+ This option causes the points on the path to be connected using piecewise
+ constant series of lines:
+ %
+\begin{codeexample}[]
+\tikz\draw plot[const plot] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/const plot mark left}
+ Just an alias for |/tikz/const plot|.
+ %
+\begin{codeexample}[]
+\tikz\draw plot[const plot mark left,mark=*] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/const plot mark right}
+ A variant of |/tikz/const plot| which places its mark on the right ends:
+ %
+\begin{codeexample}[]
+\tikz\draw plot[const plot mark right,mark=*] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/const plot mark mid}
+ A variant of |/tikz/const plot| which places its mark in the middle of the
+ horizontal lines:
+ %
+\begin{codeexample}[]
+\tikz\draw plot[const plot mark mid,mark=*] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+ More precisely, it generates vertical lines in the middle between each pair
+ of consecutive points. If the mesh width is constant, this leads to
+ symmetrically placed marks (``middle'').
+\end{key}
+
+\begin{key}{/tikz/jump mark left}
+ This option causes the points on the path to be drawn using piecewise
+ constant, non-connected series of lines. If there are any marks, they will
+ be placed on left open ends:
+ %
+\begin{codeexample}[]
+\tikz\draw plot[jump mark left, mark=*] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/jump mark right}
+ This option causes the points on the path to be drawn using piecewise
+ constant, non-connected series of lines. If there are any marks, they will
+ be placed on right open ends:
+ %
+\begin{codeexample}[]
+\tikz\draw plot[jump mark right, mark=*] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/jump mark mid}
+ This option causes the points on the path to be drawn using piecewise
+ constant, non-connected series of lines. If there are any marks, they will
+ be placed in the middle of the horizontal line segments:
+ %
+\begin{codeexample}[]
+\tikz\draw plot[jump mark mid, mark=*] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+
+ In case of non-constant mesh widths, the same remarks as for
+ |const plot mark mid| apply.
+\end{key}
+
+\begin{key}{/tikz/ycomb}
+ This option causes the |plot| operation to interpret the plotting points
+ differently. Instead of connecting them, for each point of the plot a
+ straight line is added to the path from the $x$-axis to the point,
+ resulting in a sort of ``comb'' or ``bar diagram''.
+ %
+\begin{codeexample}[]
+\tikz\draw[ultra thick] plot[ycomb,thin,mark=*] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+
+\begin{codeexample}[]
+\begin{tikzpicture}[ycomb]
+ \draw[color=red,line width=6pt]
+ plot coordinates{(0,1) (.5,1.2) (1,.6) (1.5,.7) (2,.9)};
+ \draw[color=red!50,line width=4pt,xshift=3pt]
+ plot coordinates{(0,1.2) (.5,1.3) (1,.5) (1.5,.2) (2,.5)};
+\end{tikzpicture}
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/xcomb}
+ This option works like |ycomb| except that the bars are horizontal.
+ %
+\begin{codeexample}[]
+\tikz \draw plot[xcomb,mark=x] coordinates{(1,0) (0.8,0.2) (0.6,0.4) (0.2,1)};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/polar comb}
+ This option causes a line from the origin to the point to be added to the
+ path for each plot point.
+ %
+\begin{codeexample}[]
+\tikz \draw plot[polar comb,
+ mark=pentagon*,mark options={fill=white,draw=red},mark size=4pt]
+ coordinates {(0:1cm) (30:1.5cm) (160:.5cm) (250:2cm) (-60:.8cm)};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/ybar}
+ This option produces fillable bar plots. It is thus very similar to
+ |ycomb|, but it employs rectangular shapes instead of line-to operations.
+ It thus allows to use any fill or pattern style.
+ %
+\begin{codeexample}[]
+\tikz\draw[draw=blue,fill=blue!60!black] plot[ybar] file{plots/pgfmanual-sine.table};
+\end{codeexample}
+
+\begin{codeexample}[]
+\begin{tikzpicture}[ybar]
+ \draw[color=red,fill=red!80,bar width=6pt]
+ plot coordinates{(0,1) (.5,1.2) (1,.6) (1.5,.7) (2,.9)};
+ \draw[color=red!50,fill=red!20,bar width=4pt,bar shift=3pt]
+ plot coordinates{(0,1.2) (.5,1.3) (1,.5) (1.5,.2) (2,.5)};
+\end{tikzpicture}
+\end{codeexample}
+ %
+ The use of |bar width| and |bar shift| is explained in the |plothandlers|
+ library documentation, section~\ref{section-plotlib-bar-handlers}. Please
+ refer to page~\pageref{key-bar-width}.
+\end{key}
+
+\begin{key}{/tikz/xbar}
+ This option works like |ybar| except that the bars are horizontal.
+ %
+\begin{codeexample}[preamble={\usetikzlibrary{patterns}}]
+\tikz \draw[pattern=north west lines] plot[xbar]
+ coordinates{(1,0) (0.4,1) (1.7,2) (1.6,3)};
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/ybar interval}
+ As |/tikz/ybar|, this options produces vertical bars. However, bars are
+ centered at coordinate \emph{intervals} instead of interval edges, and the
+ bar's width is also determined relatively to the interval's length:
+ %
+\begin{codeexample}[]
+\begin{tikzpicture}[ybar interval,x=10pt]
+ \draw[color=red,fill=red!80]
+ plot coordinates{(0,2) (2,1.2) (3,.3) (5,1.7) (8,.9) (9,.9)};
+\end{tikzpicture}
+\end{codeexample}
+ %
+ Since there are $N$ intervals $[x_i,x_{i+1}]$ for given $N+1$ coordinates,
+ you will always have one coordinate more than bars. The last $y$ value will
+ be ignored.
+
+ You can configure relative shifts and relative bar widths, which is
+ explained in the |plothandlers| library documentation,
+ section~\ref{section-plotlib-bar-handlers}. Please refer to
+ page~\pageref{key-bar-interval-width}.
+\end{key}
+
+\begin{key}{/tikz/xbar interval}
+ Works like |ybar interval|, but for horizontal bar plots.
+ %
+\begin{codeexample}[]
+\begin{tikzpicture}[xbar interval,x=0.5cm,y=0.5cm]
+ \draw[color=red,fill=red!80]
+ plot coordinates {(3,0) (2,1) (4,1.5) (1,4) (2,6) (2,7)};
+\end{tikzpicture}
+\end{codeexample}
+ %
+\end{key}
+
+\begin{key}{/tikz/only marks}
+ This option causes only marks to be shown; no path segments are added to
+ the actual path. This can be useful for quickly adding some marks to a
+ path.
+ %
+\begin{codeexample}[]
+\tikz \draw (0,0) sin (1,1) cos (2,0)
+ plot[only marks,mark=x] coordinates{(0,0) (1,1) (2,0) (3,-1)};
+\end{codeexample}
+\end{key}