%%
%% A DANTE-Edition example
%%
%%
%% 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{201.70511pt}
\setlength\parindent{0pt}
\usepackage{pstricks-add}
\begin{document}
\psset{unit=2cm}
\begin{pspicture}(-2.5,-1.5)(2.5,2.5)
\psaxes{->}(0,0)(-2.5,-1.5)(2.5,2.5)
\psplot[linewidth=1.5pt,algebraic]{-2.5}{+2.5}{(2*x+4)/(2+x^2)}
\psline[linestyle=dashed](-1.5,-1.5)(2.5,2.5)
\def\function{ xVal dup add 4 add xVal dup mul 2 add div }%
\pstVerb{ /xVal -1 def }% start value
\multido{\nA=0+1}{10}{%
\psline[linestyle=dotted](! xVal 0 )(! xVal xVal)
\psline[linecolor=red](! xVal xVal )(! xVal \function )
\psline[linecolor=red](! xVal \function )(! \function\space dup)
\pstVerb{ /xVal \function\space def}
}
\end{pspicture}
\end{document}
