% Written by Gun Srijuntongsiri

function C=mul(A,B)
% MUL multiplies matrix A and B together without using
%   Matlab's built-in array multiplication (A.*B)

% First check for correct dimension
if (length(size(A))~= length(size(B))) | any(size(A)~=size(B))
    error('The two arrays must have the same dimension.');
end

% Then compute the summation entry by entry.
for i=1:size(A,1)
    for j=1:size(A,2)
        C(i,j) = A(i,j)*B(i,j);
    end
end