plt.legend()画图例的几种例子

几种例子"/>

plt.legend()画图例的几种例子

参考文档链接：/

1.Place the legend inside

To place the legend inside, simply call legend():

import matplotlib.pyplot as plt
import numpy as npy = [2,4,6,8,10,12,14,16,18,20]
y2 = [10,11,12,13,14,15,16,17,18,19]
x = np.arange(10)
fig = plt.figure()
ax = plt.subplot(111)
ax.plot(x, y, label='$y = numbers')
ax.plot(x, y2, label='$y2 = other numbers')
plt.title('Legend inside')
ax.legend()
plt.show()

plt.legend()的参数loc与bbox_to_anchor

• loc的取值：best/ upper right / upper left/ lower right / lower left/ center right / center left/ lower center / lower center/ center
• bbox_to_anchor是box的定位坐标

2.Place the legend on bottom

import matplotlib.pyplot as plt
import numpy as npdef gamma(x):ans = 1#注意：不能用range(5)，这样会从0开始，导致ans的值永远为0for i in range(1,x):ans = ans * ireturn ansdef beta(x, m, n):return (gamma(m+n) / (gamma(m) * gamma(n))) * x**(m-1) * (1-x)**(n-1)x = np.linspace(0, 1, 1000)y = beta(x, 2, 3)
plt.plot(x, y, label="Beta(2,3)")
plt.legend(loc="lower center")
plt.title('Beta(2,3)')
plt.show()

画多张子图

fig = plt.figure()
axis = plot.subplot(111) #1行1列，当前是第1个

3.Place the legend outside

chartBox = ax.get_position()
ax.set_position([chartBox.x0, chartBox.y0, chartBox.width*0.6, chartBox.height])
ax.legend(loc='upper center', bbox_to_anchor=(1.45, 0.8), shadow=True, ncol=1)

Code：

import matplotlib.pyplot as plt
import numpy as npy = [2,4,6,8,10,12,14,16,18,20]
y2 = [10,11,12,13,14,15,16,17,18,19]
x = np.arange(10)
fig = plt.figure()
ax = plt.subplot(111)
ax.plot(x, y, label='$y = numbers')
ax.plot(x, y2, label='$y2 = other numbers')
plt.title('Legend outside')
chartBox = ax.get_position()
ax.set_position([chartBox.x0, chartBox.y0, chartBox.width*0.6, chartBox.height])
ax.legend(loc='upper center', bbox_to_anchor=(1.45, 0.8), shadow=True, ncol=1)
plt.show()