http://glfwtfwhlsm2u5pw3b7crist7bt7fwepj2wgv3n3b64unj22v5435tyd.onion/blog/2019/10/29/the-magic-that-is-least-squares.html
Note that this is actually the very same process you probably did in calculus at school when you had to look for extremes of squared functions. 0 = d d β L ( Δ β ) 0 = 2 e T C X β − 2 Δ β T X β T C X β + 2 Δ β T W 0 = e T C X β − Δ β T ( X β T C X β + W ) e T C X β = Δ β T ( X β T C X β + W ) X β T C T e =...