matplotlib.pyplot 标记出曲线上最大点和最小点的位置

废话不多说，直接上代码。
要求：正确安装了matplotlib库

import matplotlib.pyplot as pltimport numpy as npdef demo_test():    a=np.array([0.15,0.16,0.14,0.17,0.12,0.16,0.1,0.08,0.05,0.07,0.06]);    max_indx=np.argmax(a)#max value index    min_indx=np.argmin(a)#min value index    plt.plot(a,'r-o')    plt.plot(max_indx,a[max_indx],'ks')    show_max='['+str(max_indx)+' '+str(a[max_indx])+']'    plt.annotate(show_max,xytext=(max_indx,a[max_indx]),xy=(max_indx,a[max_indx]))    plt.plot(min_indx,a[min_indx],'gs')    plt.show()if __name__=="__main__":    demo_test();

效果图如下：