How can i write::

`trace(P*P')`

where P is 2*3 matrix

P’ is Hermitian of P

also, P is on of optimization variables

How can i write::

`trace(P*P')`

where P is 2*3 matrix

P’ is Hermitian of P

also, P is on of optimization variables

`square_pos(norm(P,'fro'))`

Depending on how that is used, you might be able to avoid the squaring, thereby improving numerical properties of the problem. For instance,

`trace(P*P') <= c`

can be formulated as

`norm(P,'fro') <= sqrt(c)`