本文共 725 字，大约阅读时间需要 2 分钟。

– Start

样本方差（variance）

方差用来表述数据和均值之间的偏离程度，样本方差不同于总体方差。

样本方差公式：$S^2=\frac{{\sum }_{i=1}^n(x_i-\overline{X}{)}^2}{n-1}$

Python

import numpy as np# 定义数据集data_set1 = np.array([2, 2, 3, 3])data_set2 = np.array([0, 0, 5, 5])print(f'data_set1={data_set1}')print(f'data_set2={data_set2}')# 均值mean1 = np.mean(data_set1)mean2 = np.mean(data_set2)print(f'mean of data_set1 = {mean1}')print(f'mean of data_set2 = {mean2}')# 样本方差variance1 = np.var(data_set1, ddof=1)variance2 = np.var(data_set2, ddof=1)print(f'variance of data_set1 = {variance1}')print(f'variance of data_set2 = {variance2}')

– 更多参见：