Re: [微積,線代] 矩陣微分

看板Math作者 (考個沒完)時間13年前 (2012/08/26 17:56), 編輯推噓1(100)
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※ 引述《singlovesong (~"~)》之銘言: : || Ax+b ||^2 (2-norm) 要怎麼對A_ij 做微分呢? : A is nxn dim-matrix : x is nx1 dim-vector : b is nx1 dim-vector : 謝謝! This is a direct consequence of definition, Since ||Ax+b||^2 = Σ(i=1~n)[Σ(j=1~n)a_ij x_j + b_j]^2 --(*), the partial derivative of (*) w.r.t a_ij is 2*Σ(i=1~n)Σ(j=1~n)(a_ij x_j + b_j)*x_j. -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 74.115.1.97

08/26 21:47, , 1F
08/26 21:47, 1F
文章代碼(AID): #1GEVAtUW (Math)
文章代碼(AID): #1GEVAtUW (Math)