Unable to run tutorial: RuntimeError: CGContextRef is NULL

[amelio-vazquez-reina]

NOTE: This issue seems to be specific to OS X. See matplotlib/matplotlib#166 and matplotlib/matplotlib#2654

When running the tutorial I get the following error when plotting the trace of the samples:

In [2]: pm.traceplot(trace);
---------------------------------------------------------------------------
RuntimeError                              Traceback (most recent call last)
<ipython-input-2-a3b0fe40351f> in <module>()
----> 1 pm.traceplot(trace);

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/pymc/plots.pyc in traceplot(trace, vars, figsize, lines, combined, grid)
     77                     pass
     78 
---> 79     plt.tight_layout()
     80     return fig
     81 

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/pyplot.pyc in tight_layout(pad, h_pad, w_pad, rect)
   1253 
   1254     fig = gcf()
-> 1255     fig.tight_layout(pad=pad, h_pad=h_pad, w_pad=w_pad, rect=rect)
   1256     draw_if_interactive()
   1257 

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/figure.pyc in tight_layout(self, renderer, pad, h_pad, w_pad, rect)
   1603                                          renderer,
   1604                                          pad=pad, h_pad=h_pad, w_pad=w_pad,
-> 1605                                          rect=rect)
   1606 
   1607         self.subplots_adjust(**kwargs)

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/tight_layout.pyc in get_tight_layout_figure(fig, axes_list, subplotspec_list, renderer, pad, h_pad, w_pad, rect)
    350                                      subplot_list=subplot_list,
    351                                      ax_bbox_list=ax_bbox_list,
--> 352                                      pad=pad, h_pad=h_pad, w_pad=w_pad)
    353 
    354     if rect is not None:

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/tight_layout.pyc in auto_adjust_subplotpars(fig, renderer, nrows_ncols, num1num2_list, subplot_list, ax_bbox_list, pad, h_pad, w_pad, rect)
    127         #ax_bbox = union([ax.get_position(original=True) for ax in subplots])
    128 
--> 129         tight_bbox_raw = union([ax.get_tightbbox(renderer) for ax in subplots])
    130         tight_bbox = TransformedBbox(tight_bbox_raw,
    131                                      fig.transFigure.inverted())

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/axes.pyc in get_tightbbox(self, renderer, call_axes_locator)
   9151 
   9152         if self.title.get_visible():
-> 9153             bb.append(self.title.get_window_extent(renderer))
   9154         if self._left_title.get_visible():
   9155             bb.append(self._left_title.get_window_extent(renderer))

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/text.pyc in get_window_extent(self, renderer, dpi)
    752             raise RuntimeError('Cannot get window extent w/o renderer')
    753 
--> 754         bbox, info, descent = self._get_layout(self._renderer)
    755         x, y = self.get_position()
    756         x, y = self.get_transform().transform_point((x, y))

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/text.pyc in _get_layout(self, renderer)
    318         tmp, lp_h, lp_bl = get_text_width_height_descent('lp',
    319                                                          self._fontproperties,
--> 320                                                          ismath=False)
    321         offsety = (lp_h - lp_bl) * self._linespacing
    322 

/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.pyc in get_text_width_height_descent(self, s, prop, ismath)
    156         points = prop.get_size_in_points()
    157         size = self.points_to_pixels(points)
--> 158         width, height, descent = self.gc.get_text_width_height_descent(unicode(s), family, size, weight, style)
    159         return  width, height, 0.0*descent
    160 

RuntimeError: CGContextRef is NULL

This is all with Python 2.7.6 with a conda installation.

[jsalvatier]

I don't know what's causing this, but it looks like a matplotlib issue
related to this one (matplotlib/matplotlib#2654).

On Tue, Feb 11, 2014 at 2:53 PM, ribonoous notifications@github.com wrote:

When running the tutorialhttp://nbviewer.ipython.org/github/pymc-devs/pymc/blob/master/pymc/examples/tutorial.ipynbI get the following error when plotting the trace of the samples:

In [2]: pm.traceplot(trace);---------------------------------------------------------------------------RuntimeError Traceback (most recent call last) in ()----> 1 pm.traceplot(trace);
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/pymc/plots.pyc in traceplot(trace, vars, figsize, lines, combined, grid)
77 pass
78 ---> 79 plt.tight_layout()
80 return fig
81
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/pyplot.pyc in tight_layout(pad, h_pad, w_pad, rect)
1253
1254 fig = gcf()-> 1255 fig.tight_layout(pad=pad, h_pad=h_pad, w_pad=w_pad, rect=rect)
1256 draw_if_interactive()
1257
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/figure.pyc in tight_layout(self, renderer, pad, h_pad, w_p
ad, rect)
1603 renderer,
1604 pad=pad, h_pad=h_pad, w_pad=w_pad,-> 1605 rect=rect)
1606
1607 self.subplots_adjust(*_kwargs)
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/tight_layout.pyc in get_tight_layout_figure(fig, axes_list, subplotspec_list, renderer, pad, h_pad, w_pad, rect)
350 subplot_list=subplot_list,
351 ax_bbox_list=ax_bbox_list,--> 352 pad=pad, h_pad=h_pad, w_pad=w_pad)
353
354 if rect is not None:
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/tight_layout.pyc in auto_adjust_subplotpars(fig, renderer, nrows_ncols, num1num2_list, subplot_list, ax_bbox_list, pad, h_pad, w_pad, rect)
127 #ax_bbox = union([ax.get_position(original=True) for ax in subplots])
128 --> 129 tight_bbox_raw = union([ax.get_tightbbox(renderer) for ax in subplots])
130 tight_bbox = TransformedBbox(tight_bbox_raw,
131 fig.transFigure.inverted())
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/axes.pyc in get_tightbbox(self, renderer, call_axes_locator)
9151
9152 if self.title.get_visible():-> 9153 bb.append(self.title.get_window_extent(renderer))
9154 if self._left_title.get_visible():
9155 bb.append(self._left_title.get_window_extent(renderer))
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/text.pyc in get_window_extent(self, renderer, dpi)
752 raise RuntimeError('Cannot get window extent w/o renderer')
753 --> 754 bbox, info, descent = self._get_layout(self._renderer)
755 x, y = self.get_position()
756 x, y = self.get_transform().transform_point((x, y))
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/text.pyc in _get_layout(self, renderer)
318 tmp, lp_h, lp_bl = get_text_width_height_descent('lp',
319 self._fontproperties,--> 320 ismath=False)
321 offsety = (lp_h - lp_bl) * self._linespacing
322
/Users/josh/anaconda/envs/py27/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.pyc in get_text_width_height_descent(self, s, prop, ismath)
156 points = prop.get_size_in_points()
157 size = self.points_to_pixels(points)--> 158 width, height, descent = self.gc.get_text_width_height_descent(unicode(s), family, size, weight, style)
159 return width, height, 0.0_descent
160
RuntimeError: CGContextRef is NULL

This is all with Python 2.7.6 with a conda installation.

Reply to this email directly or view it on GitHubhttps://github.com//issues/491
.