次のエラーが発生しましたが、理由がわかりません...
>>> x = np.matrix([[1,2,3,4]])
>>> x
matrix([[1, 2, 3, 4]])
>>> pcolor(x)
<matplotlib.collections.PolyCollection object at 0x108bb1810>
>>> show()
Traceback (most recent call last):
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/artist.py", line 54, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/figure.py", line 1006, in draw
func(*args)
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/artist.py", line 54, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/axes.py", line 2086, in draw
a.draw(renderer)
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/artist.py", line 54, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/collections.py", line 755, in draw
return Collection.draw(self, renderer)
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/artist.py", line 54, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/collections.py", line 244, in draw
self.update_scalarmappable()
File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/collections.py", line 609, in update_scalarmappable
raise ValueError('Collections can only map rank 1 arrays')
ValueError: Collections can only map rank 1 arrays