n-fold Cartesian product

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Sundar Aditya 2016-5-5

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https://ww2.mathworks.cn/matlabcentral/answers/282777-n-fold-cartesian-product

评论： Sundar Aditya 2016-5-6

I need to compute the n-fold Cartesian product of a set, where n is a positive integer determined by some previous code. Is there any way to do this without using nested for-loops? ndgrid seems to be optimal for a fixed n, but I'm unable to find a solution for any general n. Thanks.

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Answer 1

John D'Errico 2016-5-5

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https://ww2.mathworks.cn/matlabcentral/answers/282777-n-fold-cartesian-product#answer_220945

在 MATLAB Online 中打开

For example:

S = 1:3;
n = 5;
q = cell(1,5);
s = repmat({S},1,n);
[Q{1:n}] = ndgrid(s{:});
Q = reshape(cat(n,Q{:}),[],n);

I'm not sure if that solution is a trivial one. Trivial is all in the eyes of the beholder anyway. To be honest, I've written a function in one of my toolboxes that does it for me, rather than have to remember this trick when I need it.