1 import matplotlib.pyplot as plt 2 import numpy as np 3 4 x = np.linspace(-3, 3, 50) 5 y1 = 2 * x + 1 6 y2 = x ** 2 7 8 #figure 1 9 plt.figure() 10 plt.plot(x, y1) 11 12 #figure 2 13 plt.figure() 14 plt.plot(x, y2) 15 16 #figure 4，指定figure的编号并指定figure的大小 17 plt.figure(num = 4, figsize = (8, 5)) 18 plt.plot(x, y1, color = "red", linewidth = 5.0, linestyle = '--') #指定线的颜色, 宽度和类型 19 plt.plot(x, y2) 20 21 plt.show()