matplotlib-users Mailing List for matplotlib

I have an application with two matplotlib figures, both using the gtkAgg
backend. One or the other is displayed on the screen depending on the
GUI state. Initially after creating the two figures, I can interact with
both of them just fine, but after switching between figures two or three
times the figure becomes sluggish in handling pans and zooms, and I
start getting errors like this while panning:

Traceback (most recent call last):
  File
"/usr/lib/pymodules/python2.6/matplotlib/backends/backend_gtk.py", line
216, in button_release_event
    FigureCanvasBase.button_release_event(self, x, y, event.button,
guiEvent=event)
  File "/usr/lib/pymodules/python2.6/matplotlib/backend_bases.py", line
1219, in button_release_event
    self.callbacks.process(s, event)
  File "/usr/lib/pymodules/python2.6/matplotlib/cbook.py", line 165, in
process
    func(*args, **kwargs)
  File "/usr/lib/pymodules/python2.6/matplotlib/backend_bases.py", line
2016, in release_pan
    a.end_pan()
  File "/usr/lib/pymodules/python2.6/matplotlib/axes.py", line 2458, in
end_pan
    del self._pan_start
AttributeError: _pan_start

I tried to create a minimum working example but so far have been
unsuccessful; the problem did not recur in the simpler program I created.

Can anyone suggest to me where I would look to find what could cause
this error and the (presumably related) performance degradation?

On Friday, December 17, 2010, Nat Echols <nat...@gm...> wrote:
> I updated the version of matplotlib distributed with our group's software to 1.0.0 a week and a half ago (we also use wxPython 2.8.11.0 and Python 2.7).  Since then, multiple users (all on Mac, so far, although we also distribute a Linux version) have been reporting this error:
>
> RuntimeError : Could not open facefile /usr/local/bin/phenix-dev-610/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/mpl-data/fonts/ttf/VeraMono.ttf; Cannot_Open_Resource
>
> The full traceback is appended below.  Googling for this turned up multiple messages relating to older versions of matplotlib, but the only solution I could find was to remove the fontCache file in ~/.matplotlib (and it appears that in some cases removing the entire directory is necessary).  The problem is that this appears to be necessary every time a user upgrades to a new version of our code and removes an older installation, and since we distribute nightly builds, it has become a daily ritual explaining how to fix the problem.  I would really appreciate it if someone can suggest a more elegant solution than making my code nuke ~/.matplotlib.  Alternately, if there is a way to completely prevent the creation or use of ~/.matplotlib, this would make my life much easier; so far this is the only Python module that I've seen that insists on writing to the home directory and crashes if it doesn't get its way.
>
> Or do I need to file a bug ticket?
>
> thanks,
> Nat
>
> Traceback (most recent call last):
>  File "/usr/local/bin/phenix-dev-613/phenix/wxGUI2/Runtime.py", line 155, in OnUpdate
>    self.propagate_event(event, "OnUpdate")
>  File "/usr/local/bin/phenix-dev-613/phenix/wxGUI2/Runtime.py", line 211, in propagate_event
>    fn(event)
>  File "/usr/local/bin/phenix-dev-613/phenix/wxGUI2/Programs/Refine/Output.py", line 517, in OnUpdate
>    self.stats_plot.update_stats(callback.data)
>  File "/usr/local/bin/phenix-dev-613/phenix/wxGUI2/Programs/Refine/Output.py", line 760, in update_stats
>    stats.bs_ave)
>  File "/usr/local/bin/phenix-dev-613/phenix/wxGUI2/Programs/Refine/Output.py", line 802, in set_plots
>    self.canvas.draw()
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/backends/backend_wxagg.py", line 59, in draw
>    FigureCanvasAgg.draw(self)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 394, in draw
>    self.figure.draw(self.renderer)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
>    draw(artist, renderer, *args, **kwargs)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/figure.py", line 798, in draw
>    func(*args)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
>    draw(artist, renderer, *args, **kwargs)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/axes.py", line 1934, in draw
>    a.draw(renderer)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
>    draw(artist, renderer, *args, **kwargs)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/axis.py", line 1017, in draw
>    tick.draw(renderer)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
>    draw(artist, renderer, *args, **kwargs)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/axis.py", line 234, in draw
>    self.label1.draw(renderer)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
>    draw(artist, renderer, *args, **kwargs)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/text.py", line 524, in draw
>    bbox, info = self._get_layout(renderer)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/text.py", line 298, in _get_layout
>    ismath=False)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 180, in get_text_width_height_descent
>    font = self._get_agg_font(prop)
>  File "/usr/local/bin/phenix-dev-613/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 221, in _get_agg_font
>    font = FT2Font(str(fname))
> RuntimeError: Could not open facefile /usr/local/bin/phenix-dev-610/build/mac-intel-osx-x86_64/base/Python.framework/Versions/Current/lib/python2.7/site-packages/matplotlib/mpl-data/fonts/ttf/VeraMono.ttf; Cannot_Open_Resource
>
>

I think this issue has been totally fixed in the development branch
and I am pretty sure it is in the maintenance branch as well.  Have
you tried the latest svn source in the v1_0_maint branch?  It should
also have many, many other fixes.

Ben Root