更新时间:2022-06-22 06:58:55
您可以通过修改 X 和 y 输入来模拟OLS加权.在OLS中,您为
β 求解
You can simulate OLS weighting by modifying the X and y inputs. In OLS, you solve β for
X t Xβ = X t y .
XtX β = Xty.
在加权OLS中,您可以解决
X t X Wβ = X t W y .
XtX W β = Xt W y.
其中 W 是具有非负项的对角矩阵.因此,存在 W 0.5 ,您可以将其表示为
where W is a diagonal matrix with nonnegative entries. It follows that W0.5 exists, and you can formulate this as
(X W 0.5 ) t (XW 0.5 )β =(X W 0.5 ) t (XW 0.5 )y ,
(X W0.5)t(XW0.5) β = (X W0.5)t(XW0.5) y,
这是具有 X W 0.5 和 W 0.5 y 的OLS问题.
which is an OLS problem with X W0.5 and W0.5 y.
因此,通过修改输入,可以使用不直接识别权重的非负约束系统.
Consequently, by modifying the inputs, you can use a non-negative constraint system which does not directly recognize weights.