Assertion error in savefig
tomwallis opened this issue · 5 comments
Unfortunately I now get a new error in journal.savefig():
---------------------------------------------------------------------------
AssertionError Traceback (most recent call last)
<ipython-input-9-90edce97ea93> in <module>()
3 fig.fig.set_figheight(6)
4 # fig.savefig('data_2014-10-27.pdf')
----> 5 journal.savefig()
/Users/tomwallis/Dropbox/Python/ipython-journal/build/lib/ipythonjournal/journal.py in savefig()
89
90 def savefig():
---> 91 get_journal().savefig()
92
93
/Users/tomwallis/Dropbox/Python/ipython-journal/build/lib/ipythonjournal/journal.py in savefig(self)
37 filename = self.get_filename(ext='.png')
38 self.ensure_path_exists()
---> 39 plt.savefig(filename, bbox_inches='tight')
40 print('<img src="files/{0}" />'.format(filename))
41
/Users/tomwallis/miniconda3/envs/py33/lib/python3.3/site-packages/matplotlib/pyplot.py in savefig(*args, **kwargs)
574 def savefig(*args, **kwargs):
575 fig = gcf()
--> 576 res = fig.savefig(*args, **kwargs)
577 draw() # need this if 'transparent=True' to reset colors
578 return res
/Users/tomwallis/miniconda3/envs/py33/lib/python3.3/site-packages/matplotlib/figure.py in savefig(self, *args, **kwargs)
1468 self.set_frameon(frameon)
1469
-> 1470 self.canvas.print_figure(*args, **kwargs)
1471
1472 if frameon:
/Users/tomwallis/miniconda3/envs/py33/lib/python3.3/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, **kwargs)
2139 **kwargs)
2140 renderer = self.figure._cachedRenderer
-> 2141 bbox_inches = self.figure.get_tightbbox(renderer)
2142
2143 bbox_artists = kwargs.pop("bbox_extra_artists", None)
/Users/tomwallis/miniconda3/envs/py33/lib/python3.3/site-packages/matplotlib/figure.py in get_tightbbox(self, renderer)
1611 bb.append(ax.get_tightbbox(renderer))
1612
-> 1613 _bbox = Bbox.union([b for b in bb if b.width != 0 or b.height != 0])
1614
1615 bbox_inches = TransformedBbox(_bbox,
/Users/tomwallis/miniconda3/envs/py33/lib/python3.3/site-packages/matplotlib/transforms.py in union(bboxes)
719 Return a :class:`Bbox` that contains all of the given bboxes.
720 """
--> 721 assert(len(bboxes))
722
723 if len(bboxes) == 1:
AssertionError:
/Users/tomwallis/miniconda3/envs/py33/lib/python3.3/site-packages/IPython/core/formatters.py:239: FormatterWarning: Exception in image/png formatter: 'NoneType' object has no attribute 'index'
FormatterWarning,
<matplotlib.figure.Figure at 0x107643bd0>
Hi Tom,
do you have anything in your figure? To me it looks like the bounding box is trivial. You could also check whether plt.savefig() and plt.savefig(bbox_inches='tight') works.
btw, it might be interesting whether the tests pass for you (just run nosetests in the repository directory).
Hi Matthias,
Hmm, ok, it's something to do with my specific figure. The example from your readme works just fine.
However, it is definitely caused by journal. plt.savefig() and plt.savefig(bbox_inches='tight') are both happy. nosetests runs two tests, OK.
The figure is a seaborn plot with two panels and a legend. I will show you the code tomorrow in the lab...
Hi Tom,
I was able to reproduce your error. Actually, plt.savefig(name, bbox_inches='tight') raised an exception as well. The reason seems to be that for some strange reason, plt.gcf() (get current figure) does not work for the seaborn figure.
I implemented an keyword argument figure to savefig that can be provided with an explicit figure object. In your example, journal.savefig(figure=fig) worked for me. If it does still not work, please check back with me.
Best,
Matthias
Great, that works. Thanks Matthias.