<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">%% 
%%  A DANTE-Edition example
%% 
%%  Example 36-00-103 on page 812.
%% 
%%  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{pst-solides3d}

\begin{document}
   \begin{pspicture}(-4,-5)(6,8)
   \psset{lightsrc=viewpoint,viewpoint=50 60 40 rtp2xyz,Decran=60}
     \psSurface[ngrid=.2 .2,incolor=yellow,linewidth=0.5\pslinewidth,
                r = 2,fillcolor=cyan,
                axesboxed,
                Zmin=0,Zmax=4](-1,-2)(1,2){
                4 x dup mul mul y dup mul add dup 4 gt {pop 4} if }
   \end{pspicture}
\end{document}
</pre></body></html>