dcrosslogistic_snn.m

神经网络的工具箱, 神经网络的工具箱,

function df_da = dcrosslogisitc_snn(a, t)
%DCROSSLOGISTIC_SNN 1st derivative of CROSSLOGISTIC_SNN.
%
%  Syntax
%
%    df_dy = dcrosslogistic_snn(y0, t0)
%
%     y0    - output
%     t0    - target
%     df_dy - derivative of CROSSLOGISTIC_SNN(y,t) with respect to y
%             in (y0, t0)
%
% See also
%
%   CROSSLOGISTIC_SNN
%


TINY = 1e-8;

a(find(a>=1.0)) = 1.0 - TINY;
a(find(a<=0.0)) = TINY;

df_da = - t./a + (1 - t)./(1 - a);