-4.5 5 setxrange
-3 3 setyrange
20 setxunit
6 6 7 SetCamPos
0 0 0 SetCamView
qplanxy
2 setlinejoin 

.1 setlinewidth
.6 setgray

16 setresolution
newpath
   pi 0 smoveto
   pi pi neg {Sin 2 mul} Courbe_
currentcpathpointstable
2 newruban
dup (jaune) (cyan) inoutputcolors
drawsolid**