logsigfx.m

用人工神经网络进行人脸识别

function [w] = logsigfx(t);

% USAGE: y = logsigfx(x)
% logsigfx returns the Boltzmann/logistic/Fermi function:
% y = 1 / ( 1 + exp(-x) )
% t is the face matrix of the system
% t can be a scalar or a matrix with
% the same dimension as x 


[ni,nj] = size(t);
un = ones(ni,nj);
w = un./(un+exp(-t));