25 setxunit
7.5 setborder
-2 7 setxrange
-5 5 setyrange
jpegmode
/a 2 def
/b 2 def

1 1 settkstep
.5 .5 setsubtkstep
2 2 setmkstep
ticks
subticks
marks
traceaxes
axesarrow
/R {settvar
#rpn#   5+ 2 * 4 * Cos (t)
} def
 0 2 pi mul  settrange
gsave
   0.75 setlinewidth
   continu
   bleu
   (R) courbepolar
grestore