使用预定义标签的图例

使用绘图定义图例标签。

import numpy as np
import matplotlib.pyplot as plt

# Make some fake data.
a = b = np.arange(0, 3, .02)
c = np.exp(a)
d = c[::-1]

# Create plots with pre-defined labels.
fig, ax = plt.subplots()
ax.plot(a, c, 'k--', label='Model length')
ax.plot(a, d, 'k:', label='Data length')
ax.plot(a, c + d, 'k', label='Total message length')

legend = ax.legend(loc='upper center', shadow=True, fontsize='x-large')

# Put a nicer background color on the legend.
legend.get_frame().set_facecolor('C0')

plt.show()

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工具书类

以下函数、方法、类和模块的使用如本例所示：

import matplotlib
matplotlib.axes.Axes.plot
matplotlib.pyplot.plot
matplotlib.axes.Axes.legend
matplotlib.pyplot.legend

出：

<function legend at 0x7faa00cfaa60>