%@AUTEUR: Manuel Luque

\psset{SphericalCoor,viewpoint= 20 10 30,Decran=30}
\psset{unit=0.75}
\begin{pspicture}(-6,-1)(6,7)
\psset{Decran=60,SphericalCoor,viewpoint= 20 20 30}
\psframe(-6,-1)(6,7)
\defFunction{para}(u,v){2 u u mul mul 2 v v mul mul add}{}{}
%\psset{fontsize=5,numfaces=all}
%\psSolid[object=surface*,
%   r=1,
%   function=para,
%   ngrid=.1 36,
%   action=writesolid,
%   file=para]
%
\psSolid[object=datfile,file=para,incolor=yellow!50]
\end{pspicture}