most unwise variant
function C = yourmtimes(A,B)
[m,namb] = size(A);
n = size(B,2);
C = zeros(m,n);
for ii = 1:m
for jj = 1:n
c1 = 0;
for k = 1:namb
c1 = c1 + A(ii,k)*B(k,jj);
end
C(ii,jj) = c1;
end
end
more
m = size(A,1);
n = size(B,2);
C = zeros(m,n);
for ii = 1:m
for jj = 1:n
C(ii,jj) = sum(A(ii,:).*B(:,jj).');
end
end
or
m = size(A,1);
n = size(B,2);
C = zeros(m,n);
for ii = 1:m
for jj = 1:n
C(ii,jj) = A(ii,:)*B(:,jj);
end
end
or
m = size(A,1);
n = size(B,2);
C = zeros(m,n);
nones = ones(n,1);
for ii = 1:m
C(ii,:) = sum(A(ii*nones,:).'.*B);
end
etc.
