📝 权重初始化-01

lawlite19 · lawlite19 · commit ec92de203875 · 2016-12-21T09:45:19.000+08:00
diff --git a/readme.md b/readme.md
@@ -185,7 +185,7 @@
 - &#28608;&#27963;&#20043;&#21518;&#30340;&#20540;&#34920;&#31034;&#65306;    
 ![$${z^{i + 1}} = f({s^i})$$](http://latex.codecogs.com/gif.latex?%5Clarge%20%24%24%7Bz%5E%7Bi%20&plus;%201%7D%7D%20%3D%20f%28%7Bs%5Ei%7D%29%24%24)&#65292;
 - &#26681;&#25454;BP&#21453;&#21521;&#20256;&#25773;&#21487;&#20197;&#24471;&#21040;&#65306;    
-![$${{\partial Cost} \over {\partial s_k^i}} = {f^'}(s_k^i)W_{k, \bullet }^{i + 1}{{\partial Cost} \over {\partial {s^{i + 1}}}}$$](http://latex.codecogs.com/gif.latex?%5Clarge%20%24%24%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20s_k%5Ei%7D%7D%20%3D%20%7Bf%5E%27%7D%28s_k%5Ei%29W_%7Bk%2C%20%5Cbullet%20%7D%5E%7Bi%20&plus;%201%7D%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20%7Bs%5E%7Bi%20&plus;%201%7D%7D%7D%7D%24%24)````````````````````````````````````(1)
+![$${{\partial Cost} \over {\partial s_k^i}} = {f^'}(s_k^i)W_{k, \bullet }^{i + 1}{{\partial Cost} \over {\partial {s^{i + 1}}}}$$](http://latex.codecogs.com/gif.latex?%5Clarge%20%24%24%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20s_k%5Ei%7D%7D%20%3D%20%7Bf%5E%27%7D%28s_k%5Ei%29W_%7Bk%2C%20%5Cbullet%20%7D%5E%7Bi%20&plus;%201%7D%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20%7Bs%5E%7Bi%20&plus;%201%7D%7D%7D%7D%24%24)
  - &#26435;&#37325;&#30340;&#20559;&#23548;&#65288;&#26799;&#24230;&#65289;&#23601;&#20026;&#65306;    
  ![$${{\partial Cost} \over {\partial w_{l,k}^i}} = z_l^i{{\partial Cost} \over {\partial s_k^i}}$$](http://latex.codecogs.com/gif.latex?%5Clarge%20%24%24%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20w_%7Bl%2Ck%7D%5Ei%7D%7D%20%3D%20z_l%5Ei%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20s_k%5Ei%7D%7D%24%24)
  - &#36824;&#26159;BP&#21453;&#21521;&#20256;&#25773;&#30340;&#25512;&#23548;&#65292;&#21487;&#20197;&#26597;&#30475;&#25105;&#20043;&#21069;&#32473;&#30340;BP&#21453;&#21521;&#20256;&#25773;&#30340;&#25512;&#23548;&#12290;

-Original file line number
+Diff line change
 - 激活之后的值表示：
 ![$${z^{i + 1}} = f({s^i})$$](http://latex.codecogs.com/gif.latex?%5Clarge%20%24%24%7Bz%5E%7Bi%20&plus;%201%7D%7D%20%3D%20f%28%7Bs%5Ei%7D%29%24%24)，
 - 根据BP反向传播可以得到：
 -![$${{\partial Cost} \over {\partial s_k^i}} = {f^'}(s_k^i)W_{k, \bullet }^{i + 1}{{\partial Cost} \over {\partial {s^{i + 1}}}}$$](http://latex.codecogs.com/gif.latex?%5Clarge%20%24%24%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20s_k%5Ei%7D%7D%20%3D%20%7Bf%5E%27%7D%28s_k%5Ei%29W_%7Bk%2C%20%5Cbullet%20%7D%5E%7Bi%20&plus;%201%7D%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20%7Bs%5E%7Bi%20&plus;%201%7D%7D%7D%7D%24%24)````````````````````````````````````(1)
 +![$${{\partial Cost} \over {\partial s_k^i}} = {f^'}(s_k^i)W_{k, \bullet }^{i + 1}{{\partial Cost} \over {\partial {s^{i + 1}}}}$$](http://latex.codecogs.com/gif.latex?%5Clarge%20%24%24%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20s_k%5Ei%7D%7D%20%3D%20%7Bf%5E%27%7D%28s_k%5Ei%29W_%7Bk%2C%20%5Cbullet%20%7D%5E%7Bi%20&plus;%201%7D%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20%7Bs%5E%7Bi%20&plus;%201%7D%7D%7D%7D%24%24)
  - 权重的偏导（梯度）就为：
  ![$${{\partial Cost} \over {\partial w_{l,k}^i}} = z_l^i{{\partial Cost} \over {\partial s_k^i}}$$](http://latex.codecogs.com/gif.latex?%5Clarge%20%24%24%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20w_%7Bl%2Ck%7D%5Ei%7D%7D%20%3D%20z_l%5Ei%7B%7B%5Cpartial%20Cost%7D%20%5Cover%20%7B%5Cpartial%20s_k%5Ei%7D%7D%24%24)
  - 还是BP反向传播的推导，可以查看我之前给的BP反向传播的推导。