Re: [Matplotlib-users] GPF on XP

[John H. <jdh...@ac...>]

>>>>> "Robert" == Robert Leftwich <ro...@le...> writes:

    Robert> When attempting to generate a larger number of graph sets
    Robert> (i.e. 3 graphs of similar style over different data
    Robert> ranges), I'm intermittently getting a GPF on XP in
    Robert> na_backend_agg.pyd according to the report that M$ offers
    Robert> to send to itself.

Ouch.

    Robert> It is repeatable in one sense, in that if I restart the
    Robert> graph generation from the beginning it will fail at the
    Robert> same set, but if skip the first set of graphs it doesn't
    Robert> produce one additional set and then die, it dies at 15 (5
    Robert> sets) earlier. I can restart from any of the sets where it
    Robert> failed and it will continue on for some random number
    Robert> before GPF'ing again - anything from 9 thru to 150 graphs
    Robert> or so.

Repeatable is good.  Standalone much better.  So you are running the
pure Agg backend (no GUI?).  It would help to post the output of 

  c:> python myscript.py --verbose-helpful

    Robert> If I use Numeric (23.7, the latest) it is a lot worse -
    Robert> meaning fewer sets before failure. Also matplotlib 0.72
    Robert> was a lot worse with either Numeric and numarray.

It probably won't happen with 0.71 and this would be worth testing.  I
did a bunch of changes in backend agg in 0.72, including using the
numeric API rather than the sequence protocol.  If you want to verify
that the problem was introduced in 0.72 (which will help me narrow
down the possible culprits) remove site-packages/matplotlib and then
install 0.71 and see if the crash disappears.

    Robert> I'm not sure of the best way to proceed from here - is
    Robert> this a known issue or related to one or should I attempt
    Robert> to produce a standalone test that causes the problem?

That would help immensely.

One thing I can do is send you a debug build of mpl for windows that
has a bunch of extra diagnostic information turned on.  This might
help isolate which function is causing the problem.  But if you can
get a standalone script, that would be most efficient.

Thanks,