Multiplying each column in matrix by the corresponding row in a vector

Question

I have a 6231x16825 matrix H and a 16825x1 column vector W.

For example, if W = [2; 3; 3 ...]' and H = [1 2 3; 4 5 6 ...], I need to obtain:

prod = [1*2 2*3 3*3; 4*2 5*3 6*3]

How to do this? Thanks

Answer 1

There are many ways possible, choose the one that fits you:

• Using bsxfun:

  res = bsxfun(@times, H, W(:).');
  

• Matrix multiplication:

  res = diag(W) * H;
  

• A loop:

   res = nan(size(H));
   for k = 1:size(H,2)
       res(:, k)= W .* H(:, k);
   end