Generating a vector containing the sizes of all cells of a cell array, along a specific dimension

Asked by Paolo Binetti on 25 Jan 2017

Latest activity Commented on by Paolo Binetti on 26 Jan 2017

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sample.mat

Is there a way to vectorize this? (I tried with "cellfun", but did not succeed).

for i = 1:numel(a)
    s(i) = size(a{i}, 1);
end

Where a sample of "a" is provided in attachment.

2 Comments

the cyclist on 25 Jan 2017

It would be much easier to help if you posted code that actually creates a small example of a, rather than pseudocode that illustrates what you mean.

AGA
AGA

meant to represent a 2x3 character array? So, is it correct that

a{1,1} = ['AGA';'AGA'];

would be an example of one element? It seems like that's what you mean, but wanted to be sure.

Paolo Binetti on 25 Jan 2017

Sorry, I just uploaded a .mat file with "a"

2 Answers

Link

Answer by the cyclist on 25 Jan 2017

Edited by the cyclist on 25 Jan 2017

Accepted Answer

Does this give what you want?

s = cellfun(@(x)size(x,1),a);

1 Comment

Paolo Binetti on 25 Jan 2017

Yes, I see the syntax now, thank you.

Link

Answer by Jan on 26 Jan 2017

Edited by Jan on 26 Jan 2017

cellfun has some builtin-functions, which are provided as strings and much faster than using anomyous functions:

s = cellfun('size', a, 1)

Unfortunately they appear in the docs as "Backward compatibility" only, but they are jewels.

1 Comment

Paolo Binetti on 26 Jan 2017

Thank you, it also works, and is indeed faster.

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