%% 
%%  Ein Beispiel der DANTE-Edition
%%  
%%  7. Auflage
%% 
%%  Beispiel 32-03-60 auf Seite 759.
%% 
%%  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
%% 
%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{169.16928pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\usepackage{pst-electricfield}
%StopShownPreambleCommands
\begin{document}
\begin{pspicture*}(-5,-5)(5,5)
\psgrid[subgriddiv=0,gridcolor=lightgray,
  griddots=10]
\psElectricfield[Q={[1 -2 0][1 2 0]},
  linecolor=red,N=15,points=500]
\psEquipotential[Q={[1 -2 0][1 2 0]},
  linecolor=blue,Vmin=0,Vmax=20,
  stepV=2](-5,-5)(5,5)
\psEquipotential[Q={[1 -2 0][1 2 0]},
  linecolor=green,Vmin=9,
  Vmax=9](-5,-5)(5,5)
\end{pspicture*}
\end{document}
