MATLAB: I want to read 24 images and stores value of omega,imou,nb into mat file, but some error in the program…

matrix read

function [timeelapsed1] = matfileforallimages()
%create .mat file and calculates weights of each binary image in the database
clc;
clear all;
% database veins
nuser=4;
nrep=6;
path='C:\Program Files\MATLAB\R2013a\bin\img\PCA\my_PhD_Programs\DorsalVeinsDEMO\templates';
for iuser=1:nuser
    for irep=1:nrep
        nfichd=['binaryROImano-',num2str(iuser,'%.3d'),'-',num2str(irep,'%.3d')];
        nfichd=[path,'\',nfichd,'.bmp'];        
        image1=imread(nfichd,'bmp');
        %cd ..
        timeelapsed1=cputime;
        [irow,icol]=size(image1);
        S=reshape(image1, irow*icol, 1);
        %image mean
        imoy=[];
        imoy=mean(S,2);
        S=double(S);
        %eigen values and eigen vectors for the matrix L=S'S
        L=S'*S;
        [vv dd]=eig(L);
        v=[];
        d=[];
        for i=1:size(vv,2)
            if (dd(i,i)>1e-4)
                v=[v vv(:,i)];
                d=[d dd(i,i)]; 
            end
        end
        %sort eigen values of L=S'S
        [dtemp index]=sort(d,'descend');
        for i=1:length(d)
            vtemp(:,i)=v(:,index(i));
        end
        d=dtemp;
        v=vtemp;
        %normalize eigen vectors of L=S'S
        for i=1:size(v,2)    
            kk=v(:,i);
            temp=sqrt(sum(kk.^2));
            v(:,i)=v(:,i)./temp;   
        end
        %eigen values and eigen vectors for the covariance matrix C=SS'
        u=[];
        for i=1:size(v,2)
            temp=sqrt(d(i));
            u=[u (S*v(:,i))./temp];
        end
        %normalize eigen vectors of C
        for i=1:size(u,2)
            kk=u(:,i);
            temp=sqrt(sum(kk.^2));
            u(:,i)=u(:,i)./temp;
        end
        %number of eliminated components from the eigen base
        nb=0;
        %weights of database's images
        omega=[];
        for h=1:size(S,2)
            ww=[];
            for i=1:size(u,2)-nb
                t=u(:,i);
                Weight=dot(t,S(:,h)');
                ww=[ww;Weight]; 
            end
            omega=[omega,ww]; 
        end
        M=4;
        save('omega1', 'omega', 'imoy', 'u', 'nb', 'M') %omega contains the extracted features of database images
    end
end

Best Answer

Balaji - note that on each iteration of the second loop you are saving the data to file
 for iuser=1:nuser
      for irep=1:nrep
        ...
        M=4;
        save('omega1', 'omega', 'imoy', 'u', 'nb', 'M') %omega contains the extracted features of database images
      end
 end
which means that you are overwriting the data in the omega1 file on each of these iterations. So the only data in this file corresponds to the 24th iteration.
If you want to store all of this data to the same file, then I suggest that you create some cell arrays (in case your matrix dimensions change on any iteration) to store the data from each iteration. Once you have finished looping over all of these files, then save the cell array data to file (doing this outside of the outer for loop.
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