反向传导算法

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[译者注:
[译者注:
-
 
+
:<math>
 +
\begin{align}
 +
\delta^{(n_l)}_i &= \frac{\partial}{\partial z^{n_l}_i}J(W,b;x,y)
 +
= \frac{\partial}{\partial z^{n_l}_i}\frac{1}{2} \left\|y - h_{W,b}(x)\right\|^2 \\
 +
&= \frac{\partial}{\partial z^{n_l}_i}\frac{1}{2} \sum_{j=1}^{S_{n_l}} (y_j-a_j^{(n_l)})^2
 +
= \frac{\partial}{\partial z^{n_l}_i}\frac{1}{2} \sum_{j=1}^{S_{n_l}} (y_j-f(z_j^{(n_l)}))^2 \\
 +
&= - (y_i - f(z_j^{(n_l)})) \cdot f'(z^{(n_l)}_i)
 +
= - (y_i - a^{(n_l)}_i) \cdot f'(z^{(n_l)}_i)
 +
\end{align}
 +
</math>
]
]

Revision as of 13:52, 9 April 2013

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