Présentation de 29400.jps

250 setwidth
250 setheight
7.5 setborder
-1.2 1.2 setxrange
-1.2 1.2 setyrange
jpegmode
/quadrillagegray 0.6 def
.2 setquadrillagexstep
.2 setquadrillageystep
quadrillage
1 1 settkstep
.5 .5 setsubtkstep
2 2 setmkstep
ticks
subticks
marks
traceaxes
axesarrow
/R {settvar
    t sin t sin mul t cos t cos mul add .2 200 pi mul t mul sin mul add
} def
  0  2 pi mul settrange
gsave
   4 setcurvelinewidth
   continu
   magenta
   (R) courbepolar
grestore