Confusion matrix with LaTeX

The following code generates a confusion matrix whose diagonal elements have colored background.


[code language="latex"]
\documentclass{article}
\usepackage{tabularx}
\usepackage{colortbl}
\usepackage{hhline}

\begin{document}

\begin{tabularx}{.7\textwidth}{>{\bfseries}c|c c c |}
 & A & B & \multicolumn{1}{c}{C} \
\hhline{----}
A & 4 \cellcolor[gray]{.8}& 1 & 0  \
B & 0 & 5 \cellcolor[gray]{.8}& 0  \
C & 0 & 2 & 3 \cellcolor[gray]{.8} \
\hhline{~---}
\end{tabularx}

\end{document}
[/code]