# coding:utf-8 import numpy as np import matplotlib.pyplot as plt x = np.arange(-5/2,5/2,0.01) y = -x**3+x**2+np.e+x**4 dy = lambda x:-3*x**2+2*x+4*x**3 dyy = lambda x:-6*x+2+12*x**2 a = 0.001 def sgd_func(n): x0=-10 ady = [] for i in range(n): # x0 = x0 -a*dy(x0) x0 = x0 - dy(x0)/dyy(x0) ady.append(x0) return x0,ady x0,ady = sgd_func(10) y0 = x0**2+x0+np.e plt.subplot(1,2,1) plt.plot(ady) plt.subplot(1,2,2) plt.plot(x,y) plt.text(x0,y0,'* min_value') plt.show()
