-2 2 setxrange 
-2 2 setyrange 
 
/X {settvar 
    t Cos t Sin dup mul sub 
} def 
/Y {settvar 
    t Sin t Cos 1 add mul 
} def 
 
0  2 pi mul settrange  
continu 
 
/dessin { 
   tracerepere 
   marks 
   1 dict begin 
   1.5 setlinewidth 
   gsave 
      bleu 
      {X} {Y} courbeparam 
   grestore 
   end 
} def 
 
{dessin} relief