Draw a Graph
Drawing is basic usage of TeX. Perhaps you know graphviz, another drawing languages:
main.gv:
digraph G{
a -> b -> {c, d}
}
dot -Tpng -omain.png main.gv
You don't need to declare the position of node a, b, c and d. The compiler of graphviz will calculate it:
dot main.gv
digraph G { graph [bb="0,0,126,180"]; node [label="\N"]; { c [height=0.5, pos="27,18", width=0.75]; d [height=0.5, pos="99,18", width=0.75]; } a [height=0.5, pos="63,162", width=0.75]; b [height=0.5, pos="63,90", width=0.75]; a -> b [pos="e,63,108.1 63,143.7 63,136.41 63,127.73 63,119.54"]; b -> c [pos="e,35.304,35.147 54.65,72.765 50.425,64.548 45.192,54.373 40.419,45.093"]; b -> d [pos="e,90.696,35.147 71.35,72.765 75.575,64.548 80.808,54.373 85.581,45.093"]; }
TeX has a TikZ library named graph drawing to provide same feature.
\documentclass[tikz]{standalone}
\usetikzlibrary{arrows.meta, graphs, graphdrawing, shapes.geometric}
\usegdlibrary{layered}
\title{graph}
\begin{document}
\begin{tikzpicture}[rounded corners, >=Stealth, auto]
\graph[layered layout, nodes={draw, align=center}]{%
a -> b -> {c, d}
};
\end{tikzpicture}
\end{document}
Different from graphviz, you can use powerful TeX syntax in graph drawing.
Run lx build for
this example:
This example only supports LuaTeX, not pdfTeX and XeTeX.
because graph drawing is written in lua, not TeX.