psmatrix with two ncboxes in it

Question

Can somebody help me to generate two overlapping boxes in a psmatrix? What I need is an ncbox from {3,3} to {8,8} and one from {3,3} to {3,8}. I know it's possible to draw them in a separate figure, but I can't manage to put them in the same psmatrix.

\documentclass[12pt,oneside,english]{book}
\usepackage[T1]{fontenc}
\usepackage[latin9]{inputenc}
\usepackage{geometry}
\geometry{verbose,tmargin=3cm,bmargin=3cm,lmargin=3cm,rmargin=3cm}
\pagestyle{plain}
\setcounter{secnumdepth}{3}
\setcounter{tocdepth}{3}
\usepackage{float}
\usepackage{amsmath,qtree, amssymb, amsthm, graphicx,graphics, makeidx,esint,bm,pstricks,pst-node,pst-tree}


\begin{document}
\begin{figure}[H]
\begin{align*}
\psmatrix[colsep=0.7cm,rowsep=0.15cm]
\cdot \\
 \cdot  &  \cdot \\
 \cdot  &  \cdot  &  \cdot \\
 \cdot  &  \cdot  &  \cdot & \cdot \\
 \cdot  &  \cdot  &  \cdot  &  \cdot &  \cdot \\
 \cdot  &  \cdot  &  \cdot  &  \cdot  &  \cdot  &  \cdot \\
 \cdot  &  \cdot  &  \cdot &  \cdot  &  \cdot  &  \cdot  &  \cdot \\
 \cdot  &  \cdot  &  \cdot &  \cdot  &  \cdot  &  \cdot  & \cdot  & \cdot 
\ncbox[nodesep=.25cm,boxsize=.25,linearc=.2]{3,3}{8,8}
\endpsmatrix
\end{align*}\caption{\label{fig:equal sets in matrix}}
\end{figure}

\end{document}

Answer 1

it has nothing to do with psmatrix. It is a problem with undefined array cells and you'll have the same problems with horizontal lines. When you use \\ before you you have used all cells in a row then some cells are not defined. Define in the 3rd row all cells and everything will be fine:

\documentclass{book}
\usepackage{amsmath,pst-node}

\begin{document}
\begin{align*}
\psmatrix[colsep=0.7cm,rowsep=0.15cm]
 \cdot \\
 \cdot & \cdot \\
 \cdot & \cdot & \cdot & & & & &\\ % define all cells!
 \cdot & \cdot & \cdot & \cdot \\
 \cdot & \cdot & \cdot & \cdot & \cdot \\
 \cdot & \cdot & \cdot & \cdot & \cdot & \cdot \\
 \cdot & \cdot & \cdot & \cdot & \cdot & \cdot & \cdot \\
 \cdot & \cdot & \cdot & \cdot & \cdot & \cdot & \cdot & \cdot 
\ncbox[nodesep=.25cm,boxsize=.25,linearc=.2,
       fillstyle=solid,fillcolor=red!30]{3,3}{8,8}
\ncbox[nodesep=.25cm,boxsize=.25,linearc=.2,
       fillstyle=solid,fillcolor=blue!50,opacity=0.5]{3,3}{3,8}
\endpsmatrix
\end{align*}

\end{document}