[Python知识库]梯度下降法

import numpy as np
x = np.array([[3, 400], [3, 330], [3, 369], [2, 232], [4, 540]])
y = np.array([2104, 1600, 2400, 1413, 3000])
a = 0.1
b0 = np.random.random()
b1 = np.random.random()
b2 = np.random.random()
b = np.array([b1, b2])
td = 1e-4
td1 = 7
td2 = 7
td3 = 7
while td1 >= td or td2 >= td or td3 >= td:
    i = 1
    b0 = b0+a*(y[:i]-(b0+b[:i]*x[:i]))*x[:i]
    b1 = b1+b0*x[0:i]
    b2 = b2+b0*x[1:i]
    i += 1
print(b0, b1, b2)

0.327373327678322 0.22439679809042462 0.6977113806209054