28 setxunit 7.5 setborder 90 setangle_repere -3.3 1.6 setxrange -3 3 setyrange 1 1 settkstep .5 .5 setsubtkstep 1 1 setmkstep ticks subticks marks traceaxes axesarrow 1.75 setlinewidth continu bleu /X {settvar #rpn# 2*Cos(t) - Cos(2*t) } def /Y {settvar #rpn# 2*Sin(t) + Sin(2*t) } def 0 pi 2 mul {X} {Y} Courbeparam noir continu /XX {settvar #rpn# Cos(t) } def /YY {settvar #rpn# Sin(t) } def 0.75 setlinewidth 0 2 pi mul {XX} {YY} Courbeparam