Python实现皮尔逊系数计算

import numpy as np
from math import sqrt
from math import sqrt
def multipl(a, b):
    sumofab = 0.0
    for i in range(len(a)):
        temp = a[i] * b[i]
        sumofab += temp
    return sumofab
def corrcoef(x, y):
    n = len(x)
    # 求和
    sum1 = sum(x)
    sum2 = sum(y)
    # 求乘积之和
    sumofxy = multipl(x, y)
    # 求平方和
    sumofx2 = sum([pow(i, 2) for i in x])
    sumofy2 = sum([pow(j, 2) for j in y])
    num = sumofxy - (float(sum1) * float(sum2) / n)
    # 计算皮尔逊相关系数
    den = sqrt((sumofx2 - float(sum1 ** 2) / n) * (sumofy2 - float(sum2 ** 2) / n))
    print("num",num)
    print("den",den)
    return num / den

X = [1,2,3,5,8]
Y = [0.11,0.12,0.13,0.15,0.18]
print(corrcoef(X, Y) )