You don't think it a bit silly to compute the subexpression:
twice instead of doing it once? Do you pay extra if you use two lines of code? I thought there was no charge for that. You must have a different license agreement.
u = NN\eye(T);
zz = u'.*u;
You also save on the extraneous use of parens, which they also don't charge you for. But that makes it a bit easier to read and follow what was done there.