Polar coordinate graphing

[Michael O'Donnell]

I've seen graphs generated using polar coordinates,
with variables represented as radials from the
origin.  You then connect-the-dots on each axis and
your graph is the resultant shape.  I seems like
I recall a particular name for that approach and I
might have even seen some Linux software that allows
you to generate such graphs.  xgraph is cool but I
think it only does Cartesian coordinates (linear &
log) and that's not what I want...     Suggestions?