Creating a (nxn) Matrix using a for loop

How do i create a (n x n) matrix whose elements are either +3 or –3 such that the sign of each element is different from its adjacent elements, both from those above and below it and from those on either side of it (see Y below). I want to do this using a for loop.

[Andrew Newell]

You say "see Y below" but there's no Y.

[Andrew Newell]

This is a duplicate post. What's wrong with the answers to the previous question? I suggest you delete this question and go back there.

[Walter Roberson]

duplicates http://www.mathworks.com/matlabcentral/answers/5202-how-to-create-a-nxn-matrix-with-alternating-sign

Answer 1

[the cyclist]

Here's one way, without a for loop:

 A = 3*reshape((-ones(1,n^2)).^(1:n^2),[n n])

Force a for loop into that somewhere.