Re: [Matplotlib-users] WXAgg backend crashes

[Ken M. <mc...@ii...>]

On 12/12/05 10:46, Christian Kristukat wrote:
> I posted this some weeks ago however no solution was found at that time.

I'm sorry, I was under the impression that the problem was caused by some kind 
of True-Type font weirdness.  Reviewing the exchange, it appears that someone 
else reproduced the segfault and tracked it down to the presence of a 
particular font.

> Since matplotlib 0.84 - now I'm using mpl from cvs - the WXAgg backend
> crashes with a segfault after calling pylab.show().

Please try disabling the WXAgg accelerator to see if that's where the segfault 
is coming from.  Stick the following lines at the beginning of your script:

	import matplotlib.backends.backend_wxagg
	matplotlib.backends.backend_wxagg._use_accelerator(False)

A short script that consistently reproduces the problem would be helpful, as 
would the output whith verbose.level set to debug-annoying.

> I use mpl through the OO interface in a larger wxPython application and
> temporarily switched to the WX backend. However it seems that recently the tex
> support was dropped. I get a NotImplementedError when I set rcParams['usetex'] =
> True. It would be nice to have at least the tex support back, solving the
> segfault problem is possibly harder.

To the best of my knowledge, the WX backend has never supported rendering text 
with TeX.  My understanding is that you have to be using a backend that 
renders the figure with Agg (e.g. WXAgg) OR the PS backend to get TeX support.

If the segfault is being cause by the WXAgg accelerator you can switch back to 
the WXAgg backend and disable the accelerator, which would allow you to use 
TeX again.

> Btw. I can't find any agg libraries on my system which I could update. Are they
> part of mpl?

The most current version of Agg (2.3) is included with the matplotlib source 
distribution.  Matplotlib compiles the parts of Agg it needs into each Python 
extension instead of linking to a shared library, which is probably why you 
couldn't find any Agg libraries on your system.

Ken