活性化関数
(x, y) = {(-3, 9), (-2, 4), (-1, 1), (0, 0), (1, 1), (2, 4), (3, 9)}
活性化関数: φ ( u k ) = e u k ∑ i = 1 K e u i {\displaystyle \varphi (u_{k})={\frac {e^{u_{k}}}{\sum _{i=1}^{K}e^{u_{i}}}}}
誤差関数: E ( w ) = − ∑ n = 1 N ∑ k = 1 K d n , k log  y n , k {\displaystyle E(w)=-\sum _{n=1}^{N}\sum _{k=1}^{K}d_{n,k}\log y_{n,k}}
誤差関数の偏微分: ∂ E n ( w ) ∂ u k = y n , k − d n , k {\displaystyle {\frac {\partial E_{n}(w)}{\partial u_{k}}}=y_{n,k}-d_{n,k}}