* pic [#ce82732b]

pic とは，簡単なフローチャートのような図を作成するためのプログラミング言語 (A Graphics Language for Typesetting) です．

- http://www.cs.bell-labs.com/10thEdMan/pic.pdf  by Brian W. Kernighan


** dpic [#n4789561]

- https://ece.uwaterloo.ca/~aplevich/dpic/

** gpic [#re376f4f]

- http://www.math.uiuc.edu/~west/gpic.html  by  Douglas B. West


* Xy-pic [#b9215e15]

- http://tug.org/applications/Xy-pic/Xy-pic.html
- http://www.math.unm.edu/~loring/links/graph_s07/
- http://tug.org/pipermail/xy-pic/
- http://www.math.sci.hokudai.ac.jp/~abenori/tex/index.html#xy-pic
- http://akagi.ms.u-tokyo.ac.jp/ftp-j.html （日本語での解説，より詳しい解説）
- http://www.biwako.shiga-u.ac.jp/sensei/kumazawa/tex/xypic.html

** 例 [#xd92553b]
ノード近傍の重なり（接触）が多少見苦しい
 \documentclass{article} 
 \usepackage{amsmath}
 \usepackage[all]{xy}
 \begin{document}
 \xygraph{
  {     {\alpha}*+!D{\quad}="1"
    [r] {\bullet}*+!D{\text{Tokyo}}*+!U{\quad}="t"
    [d] {\bullet}*+!U{{\oalign{{Hachioji}\crcr{Tachikawa}}}} ="h"
      "1" : "t"
      "h" : "t"
      :_*+{\varDelta \tau_1} 
    [rr] {\bullet}*+!D{\text{Nagoya}}*+!U{t_1}
      :_*+{\varDelta \tau_2} 
    [rru] {\bullet}*+!D{\text{Kyoto}}*+!U{t_2} 
      :_*+{\varDelta \tau_3} 
    [rrd] {\bullet}*+!D{\text{Osaka}}*+!U{t_3} 
      :_*+{\varDelta \tau_4} 
    [rr] {\bullet}*+!D{\text{Kobe}}*+!U{\quad} ="k"
    [d] {\bullet}*+!U{\text{Sanda}} ="s"
      "s" : "k"
      "k" :  
    [r] {\beta}*+!D{\quad}
 }
 \end{document}