Variable nu nonegative

I want to do a problem with CVX, but it shows error.

I don’t know what the problem is or how to fix it. Can you help me ?

cvx_begin sdp
variable nu  semidefinite

should execute without error, and does for me (using CVX 2.1). That said, given nu is a scalar, semidefimite is the same as nonnegative.

Please copy and paste your code in your post, and use Preformatted text icon, rather than showing an image.

Please show the output from cvx_version. If you are using CVX 3.0beta, remove all CVX directories from your MATLAB path and install CVX 2.1, then run your problem and report the results to us.