Postscript problem

I am trying to overlay a polar grid on a previously plotted

    > axis. The plot looks fine on the screen and in a png file.
    > However, I get an error message when making a postscript
    > file.

Yep, this is a bug. In backend_ps in the the set_linedashes function
on line 103, replace the line

    if seq:

with

    if seq is not None and len(seq):

My guess is you are using numarray, and if memory serves numarray but
not Numeric fails on using an array as a boolean, which is what
backend ps is doing here.

Overlaying a polar plot over a rectangular axes. Man, what will they
think of next!? You will send me the screenshot when you're done,
right?

JDH