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diff --git a/Master/texmf-dist/doc/texdraw/texdraw_8.html b/Master/texmf-dist/doc/texdraw/texdraw_8.html new file mode 100644 index 00000000000..09ee5d14520 --- /dev/null +++ b/Master/texmf-dist/doc/texdraw/texdraw_8.html @@ -0,0 +1,342 @@ +<HTML> +<HEAD> +<!-- Created by texi2html 1.56k from texdraw.texi on 10 March 2004 --> + +<TITLE>TeXdraw - C. Examples</TITLE> +</HEAD> +<BODY> +Go to the <A HREF="texdraw_1.html">first</A>, <A HREF="texdraw_7.html">previous</A>, <A HREF="texdraw_9.html">next</A>, <A HREF="texdraw_11.html">last</A> section, <A HREF="texdraw_toc.html">table of contents</A>. +<P><HR><P> + + +<H1><A NAME="SEC35" HREF="texdraw_toc.html#TOC35">C. Examples</A></H1> +<P> +<A NAME="IDX183"></A> + + +<P> +This appendix shows examples of the use of TeXdraw. + + + +<UL> +<LI><A HREF="texdraw_8.html#SEC36">Block diagram</A> +<LI><A HREF="texdraw_8.html#SEC37">Filter response graph</A> +<LI><A HREF="texdraw_8.html#SEC38">Geometric construction</A> +</UL> + + + +<H2><A NAME="SEC36" HREF="texdraw_toc.html#TOC36">C.1 Block diagram of a lattice filter</A></H2> + +<P> +The block diagram of a lattice filter uses a library of extended +commands built from the basic TeXdraw commands. + + +<P> +The block diagram uses a "delay" block. This is defined as a segment +which leaves the current position at the end of this block. A second +macro, <CODE>\bdot</CODE>, draws a "big" dot which is used to mark junctions +of lines. The <CODE>\Ttext</CODE> command centers text above a given point. +The offset to position the text is local to a segment, resulting in no +change to the current point. Similar macros to position text below a +point (<CODE>\Btext</CODE>), to the left of a point (<CODE>\Ltext</CODE>) and to the +right of a point (<CODE>\Rtext</CODE>) are used in the final drawing. + +<PRE> +\def\delay {\bsegment + \setsegscale 0.3 + \lvec (0 +0.5) \lvec (1 +0.5) \lvec (1 -0.5) + \lvec (0 -0.5) \lvec (0 0) + \textref h:C v:C \htext (0.5 0){$z^{-1}$} + \savepos (1 0)(*ex *ey) + \esegment + \move (*ex *ey)} +\def\bdot {\fcir f:0 r:0.02 } +\def\Ttext #1{\bsegment + \textref h:C v:B \htext (0 +0.06){#1} + \esegment} +</PRE> + +<P> +Several of the block diagram elements scale with the size of the summing +nodes. The radius of the circles for the summing nodes is defined as +the macro <CODE>\cradius</CODE>. The summing nodes will have enclosed plus +signs, appropriately scaled. The plus sign is drawn by the macro +<CODE>\pluss</CODE>. The macro <CODE>\pcir</CODE> draws both the circle and the +plus sign. The incoming lines to a summing node will be labelled with +plus or minus signs (characters this time), placed at the appropriate +position with respect to the center of the summing node. These +positions are given in terms of compass directions. The macro +<CODE>\putwnw</CODE> places text west by north-west relative to the center of +the summing node. + +<PRE> +\def\cradius {0.08} +\def\pluss {\bsegment + \setsegscale {\cradius} + \move (-0.5 0) \lvec (+0.5 0) + \move (0 -0.5) \lvec (0 +0.5) + \esegment} +\def\pcir {\lcir r:{\cradius} \pluss} +\def\puttext (#1 #2)#3{\bsegment + \setsegscale {\cradius} + \textref h:C v:C \htext (#1 #2){#3} + \esegment} +\def\putwnw #1{\puttext (-1.7 +1.2){#1}} +</PRE> + +<P> +The block diagram has vectors arriving and departing from the summing +nodes (circles). One could calculate the points of intersection of the +lines with the circles, and then enter the values into the TeXdraw +code. However, in this example, we implement an automated procedure. +Two macros are needed, an arrow vector to a circle (<CODE>\avectoc</CODE>) and +an arrow vector leaving from a circle (<CODE>\avecfrc</CODE>). The macros +will calculate the point of intersection with the circle and start or +end the vector at the intersection point. + + +<P> +The arrow macros use scaling and relative positioning inside of a +drawing segment. In the case of the macro <CODE>\avectoc</CODE>, a move is +made to the final point (center of the circle), then within a drawing +segment, a scaled move is made back towards the initial point to +determine the intersection point with the circle. + + + +<PRE> +\def\avectoc (#1 #2){\currentpos \xa\ya + \cossin ({\xa} \ya)(#1 #2)\cosa\sina + \savepos (#1 #2)(*tx *ty) + \bsegment + \move (*tx *ty) + \setsegscale {\cradius} + \rmove ({-\cosa} -\sina) + \savecurrpos (*ex *ey) + \esegment + \avec (*ex *ey) + \move (#1 #2)} +\def\avecfrc (#1 #2){\currentpos \xa\ya + \cossin ({\xa} \ya)(#1 #2)\cosa\sina + \bsegment + \setsegscale {\cradius} + \move ({\cosa} \sina) + \savecurrpos (*ex *ey) + \esegment + \move (*ex *ey) + \avec (#1 #2)} +</PRE> + +<P> +Having defined these macros, we are ready to draw the block diagram. +The first and last sections of the lattice filter are very similar, +differing mainly in the text labels. With more effort, code could be +shared between the commands used to draw these blocks. + +<PRE> +\centertexdraw{ +\drawdim in +\arrowheadtype t:F \arrowheadsize l:0.08 w:0.04 +\def\pl {$\scriptscriptstyle +$} \def\mn {$\scriptscriptstyle -$} + +\move (0 +0.63) \move (0 -0.60) \move (0 0) % compensate for the text size + +% Input to the first stage +\bsegment + \Ltext{$x(n)$} + \lvec (0.3 0) \bdot \lvec (0.3 +0.4) \move (0.3 0) \lvec (0.3 -0.4) + \savepos (0.3 0)(*ex *ey) +\esegment +\move (*ex *ey) + +% first lattice stage +\bsegment + \move (0 +0.4) \avectoc (1.7 +0.4) + \pcir \putwnw{\pl} \puts{\mn} + \avecfrc (2.1 +0.4) + \move (0 -0.4) \avec (0.4 -0.4) \delay \avectoc (1.7 -0.4) + \pcir \putwsw{\pl} \putn{\mn} + \avecfrc (2.1 -0.4) + \move (0.9 +0.4) \bdot \avectoc (1.7 -0.4) + \move (0.9 -0.4) \bdot \avectoc (1.7 +0.4) + \move (0.1 +0.42) \Ttext {$f_0(n)$} + \move (2.0 +0.42) \Ttext {$f_1(n)$} + \move (0.1 -0.4) \Btext {$b_0(n)$} + \move (2.0 -0.4) \Btext {$b_1(n)$} + \textref h:L v:B \htext (1.15 +0.2){$K_1$} + \textref h:L v:T \htext (1.15 -0.2){$K_1$} + \savepos (2.1 0)(*ex *ey) +\esegment +\move (*ex *ey) + +% center section +\bsegment + \textref h:C v:C \htext (0.3 +0.4){$\cdots$} + \htext (0.3 -0.4){$\cdots$} + \savepos (0.6 0)(*ex *ey) +\esegment +\move (*ex *ey) + +% last lattice stage +\bsegment + \move (0 +0.4) \avectoc (1.7 +0.4) + \pcir \putwnw{\pl} \puts{\mn} + \avecfrc (2.3 +0.4) \Rtext{$e(n)$} + \move (0 -0.4) \avec (0.4 -0.4) \delay \avectoc (1.7 -0.4) + \pcir \putwsw{\pl} \putn{\mn} + \avecfrc (2.1 -0.4) + \move (0.9 +0.4) \bdot \avectoc (1.7 -0.4) + \move (0.9 -0.4) \bdot \avectoc (1.7 +0.4) + \move (0.1 +0.42) \Ttext {$f_{P-1}(n)$} + \move (2.0 +0.42) \Ttext {$f_P(n)$} + \move (0.1 -0.4) \Btext {$b_{P-1}(n)$} + \move (2.0 -0.4) \Btext {$b_P(n)$} + \textref h:L v:B \htext (1.15 +0.2){$K_P$} + \textref h:L v:T \htext (1.15 -0.2){$K_P$} +\esegment +} +</PRE> + +<P> +The macros used in this example are similar to the block diagram macros +defined in the file <TT>`blockdiagram.tex'</TT>. + + + + +<H2><A NAME="SEC37" HREF="texdraw_toc.html#TOC37">C.2 Filter response graph</A></H2> +<P> +<A NAME="IDX184"></A> + + +<P> +This example shows the response of a canonical filter. TeXdraw is +not well suited for general purpose graphing -- it has no coordinate +translation facility nor does it have separate <VAR>x</VAR> and <VAR>y</VAR> +scaling. Nonetheless, for certain simple graphs, TeXdraw is +adequate. + + +<P> +In this example, macro <CODE>\ticklab</CODE> places a labelled axis tick at a +given position. The data is specified in a straightforward manner, +having been scaled beforehand to give the desired aspect ratio for the +graph. + + + +<PRE> +\centertexdraw{ +\arrowheadtype t:F \arrowheadsize l:0.08 w:0.04 +\def\ds {\displaystyle} +\def\ticklab (#1 #2)#3{\move(#1 #2) + \bsegment + \lvec (0 0.05) + \textref h:C v:T \htext (0 -0.05){#3} + \esegment} +\def\Rtext #1{\bsegment + \textref h:L v:C \htext (+0.08 0){#1} + \esegment} + +\move (2.4 -0.3) % move to set the size + +\move (0 0) +% Axes +\avec (0 +1.4) +\move (0 0) \avec (2.2 0) \Rtext{$\omega$} +\ticklab (0 0) {0} +\ticklab (0.8 0) {$\ds {\pi \over 2N} $} +\ticklab (1.2 0) {$\omega_s$} +\ticklab (1.6 0) {$\ds {\pi \over N} $} + +\linewd 0.025 +\move (0 1) +\lvec (0.4 1) +\lvec (0.44 0.998) +\lvec (0.48 0.988) +\lvec (0.52 0.973) +\lvec (0.56 0.951) + ... +\lvec (1.08 0.233) +\lvec (1.12 0.156) +\lvec (1.16 0.078) +\lvec (1.20 0) +\lvec (1.9 0) +} +</PRE> + + + +<H2><A NAME="SEC38" HREF="texdraw_toc.html#TOC38">C.3 Geometric construction</A></H2> +<P> +<A NAME="IDX185"></A> + + +<P> +This example shows a geometric construction which places an ellipse +tangent to an enclosing circle. The size of the ellipse is determined +from geometric considerations. Macros are used to modularize the code. +The example alters the unit scale factor. This allows the drawing to be +carried out in units normalized to the radius of the circle. + + + +<PRE> +\centertexdraw{ +\arrowheadtype t:V \arrowheadsize l:0.08 w:0.04 +\linewd 0.01 +\setunitscale 1.5 % circle will have radius 1.5 inches + +\def\Btext #1{\bsegment + \textref h:C v:T \htext (0 -0.04){#1} + \esegment} +\def\Ttext #1{\bsegment + \textref h:C v:B \htext (0 +0.04){#1} + \esegment} +\def\Ltext #1{\bsegment + \textref h:R v:C \htext (-0.04 0){#1} + \esegment} +\def\bdot {\fcir f:0 r:0.0133 } +\def\vtick {\bsegment + \move (0 -0.05) \lvec (0 +0.05) + \esegment} +\def\htick {\bsegment + \move (-0.05 0) \lvec (+0.05 0) + \esegment} +\def\Hlen #1#2{\bsegment + \vtick \avec ({#1} 0) \vtick \avec (0 0) + \relsegscale 0.5 + \move ({#1} 0) \Ttext {#2} + \esegment} +\def\Vlen #1#2{\bsegment + \htick \avec (0 {#1}) \htick \avec (0 0) + \relsegscale 0.5 + \move (0 {#1}) \Ltext {#2} + \esegment} + +\lcir r:1 % circle +\move (-1.05 0) \lvec ( 1.05 0) % axes +\move (0 -1.05) \lvec (0 1.05) + +\move (0 0) \lvec (0.707 0.707) \bdot +\rmove (0.02 0.02) \textref h:L v:B \htext {X} +\move (0.707 -0.707) \bdot +\textref h:R v:T \htext(-0.02 -0.02){O} + +\move (0.5 0) % center of ellipse +\bsegment + \lellip rx:0.435 ry:0.804 + \bdot \Btext {$\beta_2$} + \move (0 0.15) \Hlen {0.435}{$|\beta_1{+}\beta_3|$} + \move (-0.7 0) \Vlen {0.804}{$|\beta_1{-}\beta_3|$} +\esegment +} +</PRE> + +<P><HR><P> +Go to the <A HREF="texdraw_1.html">first</A>, <A HREF="texdraw_7.html">previous</A>, <A HREF="texdraw_9.html">next</A>, <A HREF="texdraw_11.html">last</A> section, <A HREF="texdraw_toc.html">table of contents</A>. +</BODY> +</HTML> |