%% 
%%  A DANTE-Edition example
%% 
%%  Example 07-01-21 on page 87.
%% 
%%  Copyright (C) 2011 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{177.70511pt}
\setlength\parindent{0pt}

\usepackage{pstricks,multido}
\psset{unit=0.75}

\begin{document}
\begin{pspicture}[linewidth=3mm](4,5.5)
  \multido{\rA=0.0+0.5}{9}{%
    \psline[linecolor=red!40](\rA,0)(\rA,5)}
  \multido{\rA=0.0+0.5,\rB=0.0+0.1}{11}{%
    \psline[arrows=<D-D>,linecolor=blue,
      linewidth=5pt,arrowscale=1.5,
       strokeopacity=\rB](0,\rA)(4,\rA)}
\end{pspicture}
\end{document}
