摘要: 样本方差推导 样本方差公式$$S = \frac{1}{n 1}\sum_{i=1}^n(x_i \mu_i)^2$$ 扩展开来得到$$S = \frac{1}{n 1}[(X \frac{1}{n}X^TI_nI_n^T)^T(X \frac{1}{n}X^TI_nI_n^T)]$$ $$S = 阅读全文
posted @ 2019-04-22 13:45 Fate0729 阅读(623) 评论(0) 推荐(0)