Question

A = [1 2 3; 7 6 5]
B = [3 7];
A-B = [1-3 2-3 3-3; 7-7 6-7 5-7];
ans =[-2 -1 0; 0 -1 -2]

This is the operation I want to have done. How could I do it by matrix functions other than the iterative solutions?

Answer 1

You do this most conveniently with bsxfun, which automatically expands the arrays to match in size (so that you don’t need to use repmat). Note that I need to transpose B so that it’s a 2-by-1 array.

A = [1 2 3; 7 6 5]
B = [3 7];

result = bsxfun(@minus,A,B')

result =

-2    -1     0
 0    -1    -2