Dive into deep learning

线性回归解析解

矩阵求导

\[ \frac{\partial (\bold x^T\bold a)}{\partial\bold x}=\frac{\partial(\bold a^T\bold x)}{\partial\bold x}=\bold a\\ \frac{\partial(\bold x^T\bold x)}{\partial\bold x}=2\bold x \]

SGD: Stochastic Gradient Desent