25 setxunit 7.5 setborder -10 10 setxrange -10 10 setyrange jpegmode /k 8 def 1 1 settkstep .5 .5 setsubtkstep 2 2 setmkstep ticks subticks marks traceaxes axesarrow unites 1.75 setlinewidth continu bleu /X {settvar 2 t Cos mul k t mul Cos sub } def /Y {settvar k t Sin mul k t mul Sin sub } def 0 2 pi mul {X} {Y} Courbeparam