TikZ graph with interesting vertices

Question

I'd like to use TikZ to typeset some graphs like this one:

(Sorry for the crappy camera-phone pic)

I am familiar with \node, \path and edge, as well as with getting different arrowhead styles.

The bit that's tripping me up is getting the vertices of the graph to be these little triangular number diagrams. This one is relatively simple (the number diagrams are only 2x2), but I have others where the diagrams are 3x3 and bigger.

Would it be best to use an array environment inside each \node? Is that even possible?

Or is there a better way? Thanks!

Answer 1

The new graph drawing library in the CVS version of pgf can do this quite nicely. Exploiting the align key, and setting it to right means the node contents in this specific case can be given quite simply.

However, it does needs luatex to compile.

\documentclass[border=0.125cm]{standalone}

\usepackage{tikz}
\usetikzlibrary{graphdrawing}
\usetikzlibrary{graphs}
\usegdlibrary{layered}

\begin{document}

\begin{tikzpicture}[>=stealth, every node/.style={align=right}]

\graph [layered layout,grow=up, level distance=0.5in, sibling distance=0.5in]
    {
        "00\\0" -> "01\\0" -> {"01\\1", "11\\0"} -> "11\\1"
    };

\end{tikzpicture}

\end{document}