Hi, I want to speed up my script with double loop.

I would like to eliminate double-loop that script below has.

I have difficulty in vectorizing/optimizing the code handling multi-dimensional arrays.

A is the sz×n matrix and B is the sz×m matrix. sz is the 1×p vector.

Thus, X shall be m×n×p matrix.

Can someone suggest me the

for i = 1:n

for j = 1:m

X(j,i,[1:length(sz)]) = A(:,i)' + B(:,j)';

end

end

I would be happy if some one suggest me solutions.

Answer 1

[Stephen23]

X = permute(A,[3,2,1]) + permute(B,[2,3,1])

The data arrangement in memory is not optimal for that operation. Use BSXFUN for versions prior to R2016b.

[ArxIv]

Thank you so much for your advice!