[srm] 線性迴歸

符號定義 $$\begin{aligned} {S_{xx}} &:=\sum(x_i-\bar{x})^2 \\ {S_{xy}} &:=\sum(x_i-\bar{x})(y_i-\bar{y}) \\ \operatorname{SST} &=\operatorname{TSS}=\sum\limits_{i=1}^n (y_i-\bar{y})^2 \\ \operatorname{SSR} &=\operatorname{RegSS}=\sum\limits_{i=1}^n (\hat...