%%
%% A DANTE-Edition example
%%
%% Example 30-04-10 on page 609.
%%
%% 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}
\begin{pspicture}(-1,-3)(4.75,3)
\psaxes{->}(0,0)(-1,-3)(5,3)
\psplot[polarplot,linewidth=2pt,
algebraic,plotpoints=500]%
{0}{6.289}{2*(1+cos(x))}
\multido{\r=0.000+0.314}{21}{%
\psplotTangent[polarplot,
Derive=-2*sin(x),algebraic,
arrows=<->]%
{\r}{1.5}{2*(1+cos(x))}}
\end{pspicture}
\end{document}
