fttuck04.m

Tucker, PARAFAC, GRAM, RAFA and misc. 2nd order models with a test data set (old version now covered

function [A,B,C,G]=fttuck04(X,r1,r2,r3,W1,W2,W3);
%function [A B C G]=fttuck04(X,r1,r2,r3,W1,W2,W3);
%
%This TUCKER3 program calculates the W principal components in
%the problem Z = A(w1)*G(w1,w2,w3)*(B(w2)kronC(w3)) for wi=1,2,...,W(i);
%
%This particular procedure (fttuck04) is not iterative and simply
%calculates a core from the factors found by TUCKER1/UPCA 
%
% X        : Supermatrix (r1 x r2穜3) from cube (r1 x r2 x r3).
% r1,r2,r3 : Number of observations along each way.
% W1,W2,W3 : Number of factors.
% A,B,C	   : The found factors in columns. 
%            The dimensions will be A(r1 x W1) B(r2 x W2) C(r3 x W3).
% G        : Cube of interactions, the CORE
% Author   : Claus A. Andersson, May 1995 
% Copyright: Food Technology,
%            Royal Veterinary & Agricultural University
%            Copenhagen, Denmark
% E-mail   : [e-mail] 

disp('Calling FTUPCA01.M')
[A B C]=ftupca01(X,r1,r2,r3,W1,W2,W3);

%Updating G - the core
tmp1=zeros(W1*W2,r3);
for t=1:r3,
  tmp=(A'*X(1:r1,(t-1)*r2+1:t*r2)*B)';
  tmp1(:,t)=tmp(:);
end;
tmp2=kron(A'*A,B'*B)\tmp1*C/(C'*C);
G=zeros(W1,W2*W3);
for t=1:W3,
  G(1:W1,(t-1)*W2+1:t*W2)=reshape(tmp2(:,t)',W2,W1)';
end;
clear tmp tmp1 tmp2 t

%Calculates the misfit of factors and core
diff=0;
for k=1:r3
  tmp1=G(:,1:W2)*C(k,1);
  for l=2:W3
    tmp1=tmp1+G(:,(l-1)*W2+1:l*W2)*C(k,l);
  end;
  diff=diff+sum(sum((X(:,(k-1)*r2+1:k*r2)-A*tmp1*B').^2));
end;
fprintf('The sq. sum of misfit is %12.8f with the found factors. \n',diff);

disp('FTTUCK04: Execution ended.')