I need to use for loops to find thematrix product P and Q.

test case: P=[1 2 3 4; 5 6 7 8];

Q=[1 1 1; 2 2 2; 3 3 3;4 4 4];

M=myMatMult(P,Q)

function [ M ] = myMatMult(P,Q)

%Q is an p*n matrix

% P is an m*p matrix

%9/11/2014

% M(i,j) = P(i,:)*Q(:,j)

for m = 1:size(P, 1)

    for n = 1:size(Q, 2)

        PQ{m, n} = P(m, n) * Q;

    end

end

M = cell2mat(PQ);

disp(M);

end

Answer 1

[Roger Stafford]

What you are computing there is the Kronecker tensor product:

   M = kron(P,Q);

and not "% M(i,j) = P(i,:)*Q(:,j)". See:

   http://www.mathworks.com/help/matlab/ref/kron.html

(Incidentally, the function 'kron' does not require that the number of columns in P be the same as the number of rows in Q.)