Description
Bug report
Bug summary
plt.bar() only accept 1D arrays, and does not accept 2D arrays with a dimension that has length 1. E.g., does not accept arrays with shape (3,1). Unfortunately, the traceback is unhelpful.
Code for reproduction
from matplotlib import pyplot as plt
import numpy as np
plt.bar(np.zeros((2,)),np.zeros((2,1)))Actual outcome
File "<stdin>", line 1, in <module>
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/pyplot.py", line 2648, in bar
ret = ax.bar(*args, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/__init__.py", line 1717, in inner
return func(ax, *args, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/axes/_axes.py", line 2087, in bar
label='_nolegend_',
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/patches.py", line 659, in __init__
Patch.__init__(self, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/patches.py", line 103, in __init__
self.set_linewidth(linewidth)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/patches.py", line 351, in set_linewidth
self._linewidth = float(w)
TypeError: only length-1 arrays can be converted to Python scalars
Expected outcome
plt.bar() should be able to figure out that a 1D vector and a 2D array with a singleton dimension are equivalent. This can be done by applying squeeze if necessary. In any case if plt.bar() is going to fail unintuitively on this, it should test to see if the input is a 2D array, and provide an informative error message.
Matplotlib version
- Operating system: windows, linux, and mac
- Matplotlib version: most recent
- Matplotlib backend (
print(matplotlib.get_backend())): - Python version: 2.7 and 3.6
- Jupyter version (if applicable):
- Other libraries:
This code works with matplotlib version 1.4.2 and does not work with 2.1.1. Other pyplot functions do not exhibit this behavior. E.g., plt.plot(np.zeros((2,1)),np.zeros((2,1))) works fine.