ValueError                                Traceback (most recent call last)
~/anaconda3/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/anaconda3/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    236 
    237     if 'png' in formats:
--> 238         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    239     if 'retina' in formats or 'png2x' in formats:
    240         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/anaconda3/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    120 
    121     bytes_io = BytesIO()
--> 122     fig.canvas.print_figure(bytes_io, **kw)
    123     data = bytes_io.getvalue()
    124     if fmt == 'svg':

~/anaconda3/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, **kwargs)
   2265                 orientation=orientation,
   2266                 bbox_inches_restore=_bbox_inches_restore,
-> 2267                 **kwargs)
   2268         finally:
   2269             if bbox_inches and restore_bbox:

~/anaconda3/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, *args, **kwargs)
    505 
    506     def print_png(self, filename_or_obj, *args, **kwargs):
--> 507         FigureCanvasAgg.draw(self)
    508         renderer = self.get_renderer()
    509         original_dpi = renderer.dpi

~/anaconda3/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    428             # if toolbar:
    429             #     toolbar.set_cursor(cursors.WAIT)
--> 430             self.figure.draw(self.renderer)
    431         finally:
    432             # if toolbar:

~/anaconda3/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     53                 renderer.start_filter()
     54 
---> 55             return draw(artist, renderer, *args, **kwargs)
     56         finally:
     57             if artist.get_agg_filter() is not None:

~/anaconda3/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1297 
   1298             mimage._draw_list_compositing_images(
-> 1299                 renderer, self, artists, self.suppressComposite)
   1300 
   1301             renderer.close_group('figure')

~/anaconda3/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    136     if not_composite or not has_images:
    137         for a in artists:
--> 138             a.draw(renderer)
    139     else:
    140         # Composite any adjacent images together

~/anaconda3/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     53                 renderer.start_filter()
     54 
---> 55             return draw(artist, renderer, *args, **kwargs)
     56         finally:
     57             if artist.get_agg_filter() is not None:

~/anaconda3/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2435             renderer.stop_rasterizing()
   2436 
-> 2437         mimage._draw_list_compositing_images(renderer, self, artists)
   2438 
   2439         renderer.close_group('axes')

~/anaconda3/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    136     if not_composite or not has_images:
    137         for a in artists:
--> 138             a.draw(renderer)
    139     else:
    140         # Composite any adjacent images together

~/anaconda3/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     53                 renderer.start_filter()
     54 
---> 55             return draw(artist, renderer, *args, **kwargs)
     56         finally:
     57             if artist.get_agg_filter() is not None:

~/anaconda3/lib/python3.6/site-packages/matplotlib/axis.py in draw(self, renderer, *args, **kwargs)
   1131         renderer.open_group(__name__)
   1132 
-> 1133         ticks_to_draw = self._update_ticks(renderer)
   1134         ticklabelBoxes, ticklabelBoxes2 = self._get_tick_bboxes(ticks_to_draw,
   1135                                                                 renderer)

~/anaconda3/lib/python3.6/site-packages/matplotlib/axis.py in _update_ticks(self, renderer)
    972 
    973         interval = self.get_view_interval()
--> 974         tick_tups = list(self.iter_ticks())
    975         if self._smart_bounds and tick_tups:
    976             # handle inverted limits

~/anaconda3/lib/python3.6/site-packages/matplotlib/axis.py in iter_ticks(self)
    915         Iterate through all of the major and minor ticks.
    916         """
--> 917         majorLocs = self.major.locator()
    918         majorTicks = self.get_major_ticks(len(majorLocs))
    919         self.major.formatter.set_locs(majorLocs)

~/anaconda3/lib/python3.6/site-packages/matplotlib/ticker.py in __call__(self)
   1951     def __call__(self):
   1952         vmin, vmax = self.axis.get_view_interval()
-> 1953         return self.tick_values(vmin, vmax)
   1954 
   1955     def tick_values(self, vmin, vmax):

~/anaconda3/lib/python3.6/site-packages/matplotlib/ticker.py in tick_values(self, vmin, vmax)
   1959         vmin, vmax = mtransforms.nonsingular(
   1960             vmin, vmax, expander=1e-13, tiny=1e-14)
-> 1961         locs = self._raw_ticks(vmin, vmax)
   1962 
   1963         prune = self._prune

~/anaconda3/lib/python3.6/site-packages/matplotlib/ticker.py in _raw_ticks(self, vmin, vmax)
   1901         if self._nbins == 'auto':
   1902             if self.axis is not None:
-> 1903                 nbins = np.clip(self.axis.get_tick_space(),
   1904                                 max(1, self._min_n_ticks - 1), 9)
   1905             else:

~/anaconda3/lib/python3.6/site-packages/matplotlib/axis.py in get_tick_space(self)
   2060         size = tick.label1.get_size() * 3
   2061         if size > 0:
-> 2062             return int(np.floor(length / size))
   2063         else:
   2064             return 2**31 - 1

ValueError: cannot convert float NaN to integer