CG_CLASSIFY.m

% Version 1.000
%
% Code provided by Ruslan Salakhutdinov and Geoff Hinton
%
% Permission is granted for anyone to copy, use, modify, or distribute this
% program and accompanying programs and documents for any purpose, provided
% this copyright notice is retained and prominently displayed, along with
% a note saying that the original programs are available from our
% web page.
% The programs and documents are distributed without any warranty, express or
% implied.  As the programs were written for research purposes only, they have
% not been tested to the degree that would be advisable in any important
% application.  All use of these programs is entirely at the user's own risk.


function [f, df] = CG_CLASSIFY(VV,Dim,XX,target);

l1 = Dim(1);
l2 = Dim(2);
l3= Dim(3);
l4= Dim(4);
% l5= Dim(5);
% l6= Dim(6);
N = size(XX,1);

% Do decomversion.
 w1 = reshape(VV(1:(l1+1)*l2),l1+1,l2);
 xxx = (l1+1)*l2;
 w2 = reshape(VV(xxx+1:xxx+(l2+1)*l3),l2+1,l3);
 xxx = xxx+(l2+1)*l3;
%  w3 = reshape(VV(xxx+1:xxx+(l3+1)*l4),l3+1,l4);
%  xxx = xxx+(l3+1)*l4;
%  w4 = reshape(VV(xxx+1:xxx+(l4+1)*l5),l4+1,l5);
%  xxx = xxx+(l4+1)*l5;
 w_class = reshape(VV(xxx+1:xxx+(l3+1)*l4),l3+1,l4);


  XX = [XX ones(N,1)];
%   w1probs = 1./(1 + exp(-XX*w1)); w1probs = [w1probs  ones(N,1)];
%   w2probs = 1./(1 + exp(-w1probs*w2)); w2probs = [w2probs ones(N,1)];
    w1probs = max(0, XX*w1); w1probs = [w1probs ones(N,1)];
    w2probs = max(0, w1probs*w2); w2probs = [w2probs ones(N,1)];
%   w3probs = 1./(1 + exp(-w2probs*w3)); w3probs = [w3probs  ones(N,1)];
%   w4probs = 1./(1 + exp(-w3probs*w4)); w4probs = [w4probs  ones(N,1)];

  targetout = exp(w2probs*w_class);
  targetout = targetout./repmat(sum(targetout,2),1,10);
  f = -sum(sum( target(:,1:end).*log(targetout))) ;

IO = (targetout-target(:,1:end));
Ix_class=IO; 
dw_class =  w2probs'*Ix_class; 
% 
% Ix4 = (Ix_class*w_class').*w4probs.*(1-w4probs);
% Ix4 = Ix4(:,1:end-1);
% dw4 =  w3probs'*Ix4;
% 
% Ix3 = (Ix4*w4').*w3probs.*(1-w3probs);
% Ix3 = Ix3(:,1:end-1);
% dw3 =  w2probs'*Ix3;
w22 = logical(0 < [w1probs*w2 ones(N,1)]);
% Ix2 = (Ix_class*w_class').*w2probs.*(1-w2probs); 
Ix2 = (Ix_class*w_class').*w22;
Ix2 = Ix2(:,1:end-1);
dw2 =  w1probs'*Ix2;

w11 = logical(0 < [XX*w1 ones(N,1)]);
% Ix1 = (Ix2*w2').*w1probs.*(1-w1probs); 
Ix1 = (Ix2*w2').*w11;
Ix1 = Ix1(:,1:end-1);
dw1 =  XX'*Ix1;

df = [dw1(:)' dw2(:)' dw_class(:)']';