感知機程式碼實現(python版)
阿新 • • 發佈:2019-02-01
一、實現例子
李航《統計學方法》p29 例2.1正例:x1=(3,3), x2=(4,3),負例:x3=(1,1)二、最終效果
三、程式碼實現
import numpy as np import matplotlib.pyplot as plt p_x = np.array([[3, 3], [4, 3], [1, 1]]) y = np.array([1, 1, -1]) plt.figure() for i in range(len(p_x)): if y[i] == 1: plt.plot(p_x[i][0], p_x[i][1], 'ro') else: plt.plot(p_x[i][0], p_x[i][1], 'bo') w = np.array([1, 0]) b = 0 delta = 1 for i in range(100): choice = -1 for j in range(len(p_x)): if y[j] != np.sign(np.dot(w, p_x[0]) + b): choice = j break if choice == -1: break w = w + delta * y[choice]*p_x[choice] b = b + delta * y[choice] line_x = [0, 10] line_y = [0, 0] for i in range(len(line_x)): line_y[i] = (-w[0] * line_x[i]- b)/w[1] plt.plot(line_x, line_y) plt.savefig("picture.png")