Multiply one dimension of a 3D Matrix by a vector

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James Brown 2020-12-18

评论： James Brown 2020-12-18

I wish to element multiply the third dimension of Matrix A by vector B by for all xy points. The following operation takes 329 seconds.

Is there an operation that avoids the for loops?

My Code:

Matrix A has dimensions A(2048,200,513)

Vector B has dimension(513)

C = zeros(numx,numy,numz);

for j = 1:numy

for i = 1:numx

Az = squeeze(A(i,j,:));

C(i,j,:) = squeeze(B.*Az);

end

James Tursa 2020-12-18

编辑：James Tursa 2020-12-18

C = A .* reshape(B,1,1,[]);

For earlier versions of MATLAB that do not have implicit expansion it would be this:

C = bsxfun(@times,A,reshape(B,1,1,[]));

James Brown 2020-12-18

Excellent. Thank you.

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