adding matrix to every column in other matrix

Question

Ahmed almansory 2013-4-14

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https://ww2.mathworks.cn/matlabcentral/answers/71935-adding-matrix-to-every-column-in-other-matrix

采纳的回答： Cedric

hi all i have two matrix a 16x1024 and b 16x1 how i can adding b to every column in a ? thanks

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Answer 1

Cedric 2013-4-14

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https://ww2.mathworks.cn/matlabcentral/answers/71935-adding-matrix-to-every-column-in-other-matrix#answer_82158

编辑：Cedric 2013-4-14

在 MATLAB Online 中打开

 b_ext = repmat(b, 1, size(a, 2)) ;
 c = a + b_ext ;

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Answer 2

James Tursa 2013-4-14

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https://ww2.mathworks.cn/matlabcentral/answers/71935-adding-matrix-to-every-column-in-other-matrix#answer_82159

在 MATLAB Online 中打开

bsxfun(@plus,a,b)

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Cedric 2013-4-14

编辑：Cedric 2013-4-14

+1

I don't understand why it is slower than REPMAT though in cases where size(a,2) is not too large .. I thought that it would kill repmat when I tested.

James Tursa 2013-4-14

I haven't tested bsxfun much, but I am not surprised by the timing. I have read many accounts here for various problems and several times it has come up that explicit formulations in one way or another beat bsxfun for speed. For small problems like this one the timing is likely irrelevant anyway.

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