%% 
%%  A DANTE-Edition example
%% 
%%  Example 11-03-13 on page 130.
%% 
%%  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{153.70511pt}
\setlength\parindent{0pt}

\usepackage{pst-plot}\SpecialCoor

\begin{document}
\begin{pspicture}[showgrid](3,3)
 \pstVerb{/rad {180.0 mul 2 div} def}
 \pscustom[plotpoints=200]{%
   \psplot{0}{3}{x rad sin 1.5 add}
   \gsave
   \psline(! 3 dup rad sin 1.5 add)%
         (!3 dup rad sin neg 1.5 add)
   \psplot{3}{0}{x rad sin neg 1.5 add}
   \fill[fillcolor=lightgray,fillstyle=solid]
   \grestore
   \psplot[liftpen=2]{3}{0}{x rad sin neg 1.5 add}}
\end{pspicture}
\end{document}