Is it possible to use 'numel' in nested struct?

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pamela sulis 2016-3-9

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评论： Guillaume 2016-3-9

Hi! I use numel in a nested struct:

for i=1:9
    for j=1:size(E(1,i).bcd,2)
        for jj=1:numel(E(1,i).bcd{1,j}.b)
            if(isempty(E(1,i).bcd{1,j}.b{jj}))
                E(1,i).bcd{1,j}.b{jj}=''
            end
        end
    end
end

but it gives this error

'Attempt to reference field of non-structure array.'

Is it possible that the error is in the use of numel? thanks

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KSSV 2016-3-9

what is E?

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Answer 1

Guillaume 2016-3-9

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编辑：Guillaume 2016-3-9

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No, the error has nothing to do with numel. As the error says, you're attempting to access a field (b maybe) of something that is not a structure.

Assuming that E is really a structure. One of the cell array in the bcd fields does not contain a structure.

To check

for eidx = 1:numel(E)
  for bcdidx = 1:numel(E(eidx).bcd)
     if ~isstruct(E(eidx).bcd{bcdidx})
        warning('E(%d).bcd{%d} is not a structure', eidx, bcdidx);
     end
  end
end

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pamela sulis 2016-3-9

I try your code and I have an other error: 'Scalar index required for this type of multi-level indexing'. Thanks for your suggestion: surely there is an error in the dimensions of the struct or in the definition of the struct.

Guillaume 2016-3-9

I did make a typo in my code (used idx instead of eidx, most likely you already had a idx variable in your workspac). I've fixed it now and the code should run without error.

The problem is most likely that one of your cell array bcd is empty.

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