"Matt J" wrote in message <email@example.com>... > ....... I can see perhaps that > > ones(3,0)*ones(0,3) > > should end up being 3x3 because of the outer dimensions, but why should it end up containing zeros. - - - - - - - - - - Think of it this way, Matt. Consider the four multiplications:
Each of the elements of 3 x 3 M3 is 3. Each of the elements of 3 x 3 M2 is 2. Each of the elements of 3 x 3 M1 is 1. Therefore by extension of this trend M0 should have 3 x 3 elements and each of them should be 0. As Bruno states, it is consistent with the philosophy behind having the sum of an empty vector be 0 and its product be 1.