标签:partial 矩阵 pmb 求导 frac array
矩阵求导
开局一张图
![image](/i/l/?n=22&i=blog/1554702/202209/1554702-20220921184913612-1841265690.jpg)
分子布局与分母布局
并没完全理解,但我认为不是学数学的,不需要了解的太过细,只需要记住求导后矩阵的形状就可以了
链式法则
链式法则不变,一定要注意一个列向量对标量求导会成为一个行向量.
重要公式
\[\begin{array}{l}
\frac{\partial \pmb{x}^T \pmb{x}}{\partial \pmb{x} } = 2\pmb x^T\\
\frac{\partial \pmb{w}^T \pmb{x}}{\partial \pmb{x} } = \pmb w^T\\
\frac{\partial \pmb{x}^T \pmb A \pmb{x}}{\partial \pmb{x} } = \pmb x^T\pmb A + \pmb x^T\pmb A^T\\
\frac{\partial f}{\partial \pmb x^T } = (\frac{\partial f}{\partial \pmb{x} })^T
\end{array}
\]
标签:partial,
矩阵,
pmb,
求导,
frac,
array
From: https://www.cnblogs.com/Rannq2018/p/16716794.html