How do I make Bayesian networks?

Question

I am trying to tek up a Bayesian network with nodes, edges, and truth tables next to each node like this:

What tools can I use to make something like that? Perhaps some package from the TikZ library?

Answer 1

Here's one possibility using TikZ; the tabular material was placed inside \nodes. The shapes library was used to have elliptical nodes.

The dcolumn package was used to get columns with alignment at the decimal separator; the booktabs package was used to build the tables (in particular, no vertical rules were drawn):

\documentclass{article}
\usepackage{dcolumn}
\usepackage{booktabs}
\usepackage{tikz}
\usetikzlibrary{positioning,shapes,arrows}

\newcolumntype{M}[1]{D{.}{.}{1.#1}}

\begin{document}

\begin{tikzpicture}[
  node distance=1cm and 0cm,
  mynode/.style={draw,ellipse,text width=2cm,align=center}
]
\node[mynode] (sp) {Sprinkler};
\node[mynode,below right=of sp] (gw) {Grass wet};
\node[mynode,above right=of gw] (ra) {Rain};
\path (ra) edge[-latex] (sp)
(sp) edge[-latex] (gw) 
(gw) edge[latex-] (ra);
\node[left=0.5cm of sp]
{
\begin{tabular}{cM{2}M{2}}
\toprule
& \multicolumn{2}{c}{Sprinkler} \\
Rain & \multicolumn{1}{c}{T} & \multicolumn{1}{c}{F} \\
\cmidrule(r){1-1}\cmidrule(l){2-3}
F & 0.4 & 0.6 \\
T & 0.01 & 0.99 \\
\bottomrule
\end{tabular}
};
\node[right=0.5cm of ra]
{
\begin{tabular}{M{1}M{1}}
\toprule
\multicolumn{2}{c}{Sprinkler} \\
\multicolumn{1}{c}{T} & \multicolumn{1}{c}{F} \\
\cmidrule{1-2}
0.2 & 0.8 \\
\bottomrule
\end{tabular}
};
\node[below=0.5cm of gw]
{
\begin{tabular}{ccM{2}M{2}}
\toprule
& & \multicolumn{2}{c}{Grass wet} \\
\multicolumn{2}{l}{Sprinkler rain} & \multicolumn{1}{c}{T} & \multicolumn{1}{c}{F} \\
\cmidrule(r){1-2}\cmidrule(l){3-4}
F & F & 0.4 & 0.6 \\
F & T & 0.01 & 0.99 \\
T & F & 0.01 & 0.99 \\
T & T & 0.01 & 0.99 \\
\bottomrule
\end{tabular}
};

\end{tikzpicture}

\end{document}