961
个编辑
更改
跳到导航
跳到搜索
第122行：
第122行： − +
→Chain rule 链式法则
&= -\sum_{x\in\mathcal X, y\in\mathcal Y}p(x,y)\log (p(x,y)) + \sum_{x\in\mathcal X, y\in\mathcal Y}{p(x,y)\log(p(x))} \\[4pt]
&= -\sum_{x\in\mathcal X, y\in\mathcal Y}p(x,y)\log (p(x,y)) + \sum_{x\in\mathcal X, y\in\mathcal Y}{p(x,y)\log(p(x))} \\[4pt]
& = H(X,Y) + \sum_{x \in \mathcal X} p(x)\log (p(x) ) \\[4pt]
& = H(X,Y) + \sum_{x \in \mathcal X} p(x)\log (p(x) ) \\[4pt]
& = H(X,Y) - \Eta(X).
& = H(X,Y) - H(X).
\end{align}</math>
\end{align}</math>