%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 29-03-9 auf Seite 645.
%% 
%%  Copyright (C) 2016 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
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%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{193.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pstricks-add}
\def\Func{exch RadtoDeg sin -9.81 mul}
%StopShownPreambleCommands
\begin{document}
\psset{yunit=1.5,xunit=2,showpoints=true}
\begin{pspicture}[showgrid=true](0,-1.5)(3,2)
  \psplotDiffEqn[linecolor=black!40]{0}{3}{1 0}{\Func}
  \psplotDiffEqn[method=adams,linestyle=dashed]{0}{3}{1 0}{\Func}
  \psplotDiffEqn[method=rk4]{0}{3}{1 0}{\Func}
  \rput[rb](2.9,-0.9){Ruge-Kutta (rk4)}\rput[rb](1.9,1.3){Euler}
\end{pspicture}
\end{document}