Scalar max of cell array with structure

Question

Michael Bowles 2020-5-4

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https://ww2.mathworks.cn/matlabcentral/answers/522951-scalar-max-of-cell-array-with-structure

评论： Michael Bowles 2020-5-4

I have a cell array "myCell" with 2 dimensions and each cell has a 2D matrix and I'd like to obtain scalar value of the maximum for a given structure among all the cell dimensions. I assume bsxfun can do this but my goal doesn't match they way that I normally see bsxfun get used.

Currently I get the max (of the abs) looping through each cell dimension, grabbing the max for all elements in that cell's structure I need, assign the (scalar) max to elements in a matirx which shares the cell array dimensions, then tak the max of the matrix with (:) as shown below.

peak_FcRn(noFc,noRa)=0; % each cell array has  structure, whose maxes I want to compare
for iFc=1:noFc
    for iRa=1:noRa
        % get the maximum absolute value of the current cell array's structure 
        % called noise (myCell{iRa,iFc}.noise--2 or 3d array)
        peak_FcRn(iFc,iRa) = max(abs(myCell{iRa,iFc}.noise(:))); % a scalar value
    end
end
% the
peak = max(peak_FcRn(:)); %

This gets the right answer but I would really like a one- or two-liner that can get the max of the cell's structure elements--and I have a feeling bsxfun can do it!

In the laziest way I would type

peak = max(abs(myCell{:,:}.noise(:))) % or perhaps
peak = max(abs(myCell{:}.noise(:))) 

Thanks for your input,

Michael B.

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darova 2020-5-4

Try cellfun

Michael Bowles 2020-5-4

在 MATLAB Online 中打开

Thanks for your input. I got it to work with a cute two-liner!

peakPerCELL = cellfun(@(x) max(abs(x.noise(:))),myCell);
peak = max(peakPerPADS(:));

Cheers!

Michael B.

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Answer 1

James Tursa 2020-5-4

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If you reshape the input first, a one-liner version of your code:

peak = max(cellfun(@(x) max(abs(x.noise(:))),myCell(:)));

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James Tursa 2020-5-4

编辑：James Tursa 2020-5-4

The myCell(:) reshapes myCell into a column vector and passes that into cellfun( ), which in turn creates the output with the same shape as the input ... a column vector. Since the output is now already a column vector, no need to reshape it again before taking max( ).

Michael Bowles 2020-5-4

I understand and realize my question is silly now! I confused my self before posting my second question because I thought I hadn't changed the last cellfun input with (:).

Thanks for your help! I learned great stuff today!

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