python matplotlib实现双Y轴的实例

import matplotlib.pyplot as pltimport numpy as np x = np.arange(0., np.e, 0.01)y1 = np.exp(-x)y2 = np.log(x)fig = plt.figure()ax1 = fig.add_subplot(111)ax1.plot(x, y1,'r',label="right");ax1.legend(loc=1)ax1.set_ylabel('Y values for exp(-x)');ax2 = ax1.twinx() # this is the important functionax2.plot(x, y2, 'g',label = "left")ax2.legend(loc=2)ax2.set_xlim([0, np.e]);ax2.set_ylabel('Y values for ln(x)');ax2.set_xlabel('Same X for both exp(-x) and ln(x)');plt.show()