利用python計算基尼系數

代碼實作

套用公式：

def gini(a: int, b: int) -> float:
    return 1-pow(a/(a+b), 2)-pow(b/(a+b), 2)


def gini_total(a: int, b: int, c: int, d: int) -> float:
    return (a+b)/(a+b+c+d) * gini(a, b) + (c+d)/(a+b+c+d) * gini(c, d)


print(gini(13, 98))
print(gini(24, 29))
print(gini_total(13, 98, 24, 29))
           

numpy實作

import numpy as np

def gini(data_list):
    data_length = len(data_list)
    total_sum = np.sum(data_list)
    total_gini = 0
    for i in range(data_length):
        temp_denominator = data_list[i][0] + data_list[i][1]
        temp_son = np.sum(data_list[i])
        temp_gini = 1 - np.power(data_list[i][0]/temp_denominator, 2) - np.power(data_list[i][1]/temp_denominator, 2)
        total_gini = temp_gini * temp_son / total_sum + total_gini
    return total_gini
           

測試結果