25 setxunit 7.5 setborder -20 20 setxrange -20 20 setyrange /a 1 def /b 2 def /c 10 def /resolution 1000 def 2 2 settkstep 1 1 setsubtkstep 2 2 setmkstep yticks traceaxes axesarrow unites 0.75 setlinewidth continu bleu /X {settvar #rpn# (a+b) * Cos (t) - c * Sin (t*(1+a/b)) } def /Y {settvar #rpn# (a+b) * Sin (t) +c * Cos(t*(1+a*b)) } def 0 20 pi mul {X} {Y} Courbeparam