值错误：像素的图像大小太大

Question

错误：每当我在绘图中添加图例时，它都会给出以下错误： 我不明白为什么？它在没有ax.legend()的情况下工作得非常好。

（仅相关帖子：https://github.com/matplotlib/matplotlib/pull/3451）

ValueError                                Traceback (most recent call last)
/home/abhishek/anaconda2/lib/python2.7/site-packages/IPython/core/formatters.pyc in __call__(self, obj)
    305                 pass
    306             else:
--> 307                 return printer(obj)
    308             # Finally look for special method names
    309             method = get_real_method(obj, self.print_method)

/home/abhishek/anaconda2/lib/python2.7/site-packages/IPython/core/pylabtools.pyc in <lambda>(fig)
    225 
    226     if 'png' in formats:
--> 227         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    228     if 'retina' in formats or 'png2x' in formats:
    229         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

/home/abhishek/anaconda2/lib/python2.7/site-packages/IPython/core/pylabtools.pyc in print_figure(fig, fmt, bbox_inches, **kwargs)
    117 
    118     bytes_io = BytesIO()
--> 119     fig.canvas.print_figure(bytes_io, **kw)
    120     data = bytes_io.getvalue()
    121     if fmt == 'svg':

/home/abhishek/anaconda2/lib/python2.7/site-packages/matplotlib/backend_bases.pyc in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, **kwargs)
   2242                 orientation=orientation,
   2243                 bbox_inches_restore=_bbox_inches_restore,
-> 2244                 **kwargs)
   2245         finally:
   2246             if bbox_inches and restore_bbox:

/home/abhishek/anaconda2/lib/python2.7/site-packages/matplotlib/backends/backend_agg.pyc in print_png(self, filename_or_obj, *args, **kwargs)
    543 
    544     def print_png(self, filename_or_obj, *args, **kwargs):
--> 545         FigureCanvasAgg.draw(self)
    546         renderer = self.get_renderer()
    547         original_dpi = renderer.dpi

/home/abhishek/anaconda2/lib/python2.7/site-packages/matplotlib/backends/backend_agg.pyc in draw(self)
    457         if __debug__: verbose.report('FigureCanvasAgg.draw', 'debug-annoying')
    458 
--> 459         self.renderer = self.get_renderer(cleared=True)
    460         # acquire a lock on the shared font cache
    461         RendererAgg.lock.acquire()

/home/abhishek/anaconda2/lib/python2.7/site-packages/matplotlib/backends/backend_agg.pyc in get_renderer(self, cleared)
    474 
    475         if need_new_renderer:
--> 476             self.renderer = RendererAgg(w, h, self.figure.dpi)
    477             self._lastKey = key
    478         elif cleared:

/home/abhishek/anaconda2/lib/python2.7/site-packages/matplotlib/backends/backend_agg.pyc in __init__(self, width, height, dpi)
     91         self.height = height
     92         if __debug__: verbose.report('RendererAgg.__init__ width=%s, height=%s'%(width, height), 'debug-annoying')
---> 93         self._renderer = _RendererAgg(int(width), int(height), dpi, debug=False)
     94         self._filter_renderers = []
     95 

ValueError: Image size of 388x76538 pixels is too large. It must be less than 2^16 in each direction.

<matplotlib.figure.Figure at 0x7fb7fd06c090>

代码：

    fig, ax = plt.subplots(figsize=(12,8))
    ax.margins(0.05) # Optional, just adds 5% padding to the autoscaling
    decision_region(ax)
    plot_predict(ax)
    ax.set_xlabel('x1')
    ax.set_ylabel('x2')
    ax.set_title('Hidden units: '+str(hidden_units))
    ax.legend()