MATLAB: Loop Failed for Extracting Matrix from Cell Arrays

cellcell arraycell arraysMATLABmatricesmatrixmatrix arraymatrix manipulation

The result of code below is 0 for all elements in each matrix, why?
for i=1:512
    for ii=1:64
        for iii=1:8
            img{i} = cell_img{ii}(:,:,iii); 
        end
    end
end
Where cell_image{ii} contains 64 cells, then for each cell is contains 8x8x8 matrix (there are 8 matrix, each one matrix contains 8×8 elements). What i want is to extract the whole matrix from the cell_image{ii}, so it would become a 64×8 = 512 matrix (each one matrix contains 8×8 elements). But the code above is resulting all matrix element become zero. What's wrong with that code?
Please help me… Thanks in advance.

Best Answer

If you'd used the debugger to see what was happening with your loops, you would have quickly realised that you have one loop too many, the outer loop. Your i should be a counter not a loop, that is incremented by one inside the inner most loop:
i = 1;
for ii = 1:64
  for iii = 1:8
     img{i} = cell_image{ii}(:, :, iii); %do not use image as a variable name. It's a matlab function
     i = i + 1;
   end
end
However, even better is to learn to manipulate cell arrays, the above is achieved more simply with:
img = cat(3, cell_image{:});
img = squeeze(num2cell(img, [1 2])); %I would actually not bother with this step and simply keep the 3d matrix
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