MATLab matrix multiplier not outputting the correct product..

Probably something very basic, but I cannot see why the product is making some of the correct solutions, yet the other solution outputs 0.

Example: I placed these as my test products..

A = [2,1;3,0]
x = [2;1]

   function y = myProduct(A, x)
    % The command myproduct(A,x) computes the product
    % of the matrix A and the vector x by column.

    % Set sizes
    [m, n] = size(A);
    [p, q] = size(x);

    % Check Dimensions
    if(n == p && q == 1)

    %Initializes the y vector
    y = zeros(m,1);

    for i = 1:m
    y(n) = A(n,:)*x;
    end

    else
    disp('Matrix Dimension Mismatch')
    y = [];
    end
    end

Answer 1

[the cyclist]

I think you want

y(i) = A(i,:)*x;

instead of

y(n) = A(n,:)*x;

[Ryan]

You are absolutely correct thanks. I actually just realized this a couple minutes ago when I wasn't even using the variable to iterate through my for loop... Thanks for the help.