summary of the problem

I tried to put legend outside of the axes. If I use fig.legend() method to produce legend and use bbox_inches='tight' in savefig() method. The legend is not present in the produced image (using the argument bbox_extra_artists also does not work). If I use ax.legend() instead, the legend is present in the saved image.

Code for reproduction

import matplotlib.pyplot as plt
import numpy as np
import matplotlib as mpl

x = np.arange(-5, 5, 0.1)
y1 = np.sin(x)
y2 = np.cos(x)

y3 = np.sin(2*x)
y4 = np.cos(2*x)

fig, (ax1, ax2) = plt.subplots(ncols=1, nrows=2, figsize=(10, 6))

ax1.plot(x, y1, label='sin')
ax1.plot(x, y2, label='cos')

ax2.plot(x, y3, label='sin')
ax2.plot(x, y4, label='cos')

handles, labels = ax1.get_legend_handles_labels()
# following code does not work
legend = fig.legend(handles, labels, loc='lower left', ncol=2, frameon=False,
              bbox_to_anchor=(0.12, 0.88))
plt.savefig('test.jpg', bbox_extra_artists=[legend,], bbox_inches='tight')

# following code works
# legend = ax1.legend(handles, labels, ncol=2, frameon=False,
#                     loc='lower left', bbox_to_anchor=(-0.01, 1.2))
# plt.savefig('test.jpg', bbox_inches='tight')
plt.show()

outcome

The saved images are different if I use different legend method.

using fig.legend method

using ax.legend method

Matplotlib version

• Operating system: Windows 8.1 and Linux (CentOS 7) (This problem is maybe platform independent)
• Matplotlib version: 2.0.2(Linux), 2.0.0 (Windows)
• Matplotlib backend: Qt5Agg
• Python version: 3.5.2 (Windows), 3.6.2 (Linux)

The matplotlib and python are all distributed with Anaconda.

quesiton

Is this a bug or something I do not know. Maybe there is difference between fig.legend and ax.legend method?