-1.5 1.5 setxrange
-1.5 1.5 setyrange
.5 .5 setquadrillagestep
quadrillage
.7 setlinewidth
tracerepere
gsave
   pointilles
   O 1 1 droite
   -1 1 scale
   O 1 1 droite
grestore

1.2 setlinewidth
O 1 cercle