%% 
%%  The LaTeX Graphics Companion, 2ed (first printing May 2007)
%% 
%%  Example 6-7-17 on page 428.
%% 
%%  Copyright (C) 2007 Michel Goossens, Frank Mittelbach, Denis Roegel, Sebastian Rahtz, Herbert Vo\ss 
%% 
%%  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.
%% 

\documentclass{ttctexa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{207.83385pt}
\setlength\parindent{0pt}
\StartShownPreambleCommands
\usepackage{pstricks-add,pst-func}
\StopShownPreambleCommands
\begin{document}
\begin{pspicture*}(-5,-2.2)(5.5,3.5)
\psaxes{->}(0,0)(-5,-2)(5.2,3)
\multido{\rA=0.01+0.2}{5}{%
  \psplotImp[linewidth=1pt,linecolor=blue,polarplot](-6,-6)(5,2.4)
            {r dup mul 1.0 r div sub phi sin dup mul mul \rA\space sub }}
\uput*[45](0,2){$f(r,\phi)=\left(r^2-\frac{1}{r}\right)\cdot\sin^2\phi=0$}
\pscircle[linewidth=1pt](0,0){1}
\end{pspicture*}
\end{document}
