How to multiply Multidimensional Arrays with a column vector

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Tristan
Tristan 2013-10-28
评论： Shambhavi Singh 2019-2-14
I want to multiply A with B so that C(:,:,1) is equal to A(:,:,1)*B(1) and C(:,:,2) is equal to A(:,:,2)*B(2)
>> A = cat(3, [2 8; 0 5], [1 3; 7 9])
A(:,:,1) =
2 8
0 5
A(:,:,2) =
1 3
7 9
>> B=[1 2]'
B =
1
2
I'm looking to get this:
>> C=???
C(:,:,1) =
2 8
0 5
C(:,:,2) =
2 6
14 18

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回答（3 个）

sixwwwwww
sixwwwwww 2013-10-28
编辑：sixwwwwww 2013-10-28
Dear Tristan, here is the code which performs the task:
A = cat(3, [2 8; 0 5], [1 3; 7 9]);
B=[1 2]';
for i = 1:length(B)
C(:, :, i) = B(i) * A(:, :, i);
end
disp(C)
I hope it helps. Good luck!
  5 个评论
显示 3更早的评论
Shambhavi Singh
Shambhavi Singh 2019-2-14
This should work too
C=A.*permute(B,[3 2 1]),3);
Permute switches the rows in B (So the elements of a column vector) with the third dimension

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James Tursa
James Tursa 2013-10-28
Pavel Chmelar
Pavel Chmelar 2016-1-12
Clear Matlab solution according sixwwwwww and Tristan:
B=zeros(1,1,2);
B(:)=[1,2];
C=bsxfun(@times,A,B);

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