0406 Customizing Legends

中文版：自定义图例

Customizing Plot Legends

Plot legends give meaning to a visualization, assigning meaning to the various plot elements. We previously sawhowto create a simple legend; here we’lltakealookat customizing the placement and aesthetics of the legend in Matplotlib.

The simplest legend can be created with the plt.legend() command, which automatically creates a legend for any labeled plot elements:

import matplotlib.pyplot as plt
plt.style.use('classic')

%matplotlib inline
import numpy as np

x = np.linspace(0, 10, 1000)
fig, ax = plt.subplots()
ax.plot(x, np.sin(x), '-b', label='Sine')
ax.plot(x, np.cos(x), '--r', label='Cosine')
ax.axis('equal')
leg = ax.legend();

But there aremanywayswemight want to customize such a legend. For example, we can specify the location andturnofftheframe:

ax.legend(loc='upper left', frameon=False)
fig

Wecanusethe ncol command to specify the number of columns in the legend:

ax.legend(frameon=False, loc='lower center', ncol=2)
fig

Wecanusea rounded box (fancybox) oradda shadow, change the transparency (alpha value) oftheframe, or change the padding around the text:

ax.legend(fancybox=True, framealpha=1, shadow=True, borderpad=1)
fig

For more information on available legend options, see the plt.legend docstring.