对于给定训练集
x = [4,8,5,10,12]
y = [20,50,30,70,60]
参数的定义以及设置
theta0 = theta1 = 0
alpha = 0.00001
cnt = 0
error0 = error1 = 0
thershold = 0.0000001
迭代进行
while True:
diff = [0,0]
m = len(x)
for i in range(m):
diff[0] = y[i] - (theta0+theta1*x[i])
diff[1] =(y[i] - (theta0+theta1*x[i]))*x[i]
theta0 = theta0 + alpha * diff[0]
theta1 = theta1 + alpha * diff[1]
for i in range(m):
error1 += (y[i] - (theta0+theta1*x[i]))**2
error1 /= m
if abs(error1 - error0) < thershold:
break
else:error0 = error1
cnt += 1
pass
print('theta0',theta0)
print('theta1',theta1)
print('cnt',cnt)
结果预测
print(predict(theta0,theta1,8))