300 setwidth
300 setheight
7.5 setborder
-1.5 1.5 setxrange
-1.5 1.5 setyrange
jpegmode
1 1 settkstep
.5 .5 setsubtkstep
1 1 setmkstep
ticks
subticks
marks
traceaxes
axesarrow
/X {settvar
    t Cos 3 exp
} def
/Y {settvar
    t 0.78 add Sin 3 exp
} def
  0  2 pi mul settrange
gsave
   .75 setcurvelinewidth
   continu
   bleu
   {X} {Y} courbeparam
grestore