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| Syntax highlighted code block
# 这是一个标题
# 最小二乘法
import numpy as np #科学计算库
import matplotlib.pyplot as plt #绘图库
##样本数据(Xi,Yi)，需要转换成数组(列表)形式
X=np.array([8.88,9.1,2.3,4.44,12.1,11.11,8.0,7.7,1.98,10.5])
Y=np.array([5.25,2.83,6.41,6.71,5.1,4.23,5.05,1.98,10.5,6.3])
# 初始化赋值
s1 = 0
s2 = 0
s3 = 0
s4 = 0
n = 10
# 循环累加
for i in range(n):
s1 = s1 + X[i] * Y[i]
s2 = s2 + X[i]
s3 = s3 + Y[i]
s4 = s4 + X[i] * X[i]
# 计算斜率和截距
# w2 = (s1-(s2*s3)/n)/(s4-(s2*s2)/n)
w = (n*s1-s2*s3)/(n*s4-s2*s2)
b = (s3 - w * s2) / n
print(w,b)
plt.scatter(X,Y)
x=np.linspace(0,12,100)
y=w*x+b ##函数式
plt.plot(x,y)
plt.show()
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