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 2 t Cos mul 2 t mul Cos sub
} def
/Y {settvar
    3 2 Sin mul 2 t mul Sin sub
} def
  0  2 pi mul {X} {Y} Courbeparam