Unknown error in CVX 3.0 beta

3

What @Erling said, to the max!!

Per CVXQUAD: How to use CVXQUAD's Pade Approximant instead of CVX's unreliable Successive Approximation for GP mode, log, exp, entr, rel_entr, kl_div, log_det, det_rootn, exponential cone. CVXQUAD's Quantum (Matrix) Entropy & Matrix Log related functions

Note: CVX 3.0beta is not really recommended to anyone due to its numerous bugs. Do NOT use CVXQUAD with CVX 3.0beta… Please use CVX 2.2 instead.

Unfortunately, CVXQUAD’s quantum_rel_entr doesn’t scale well, due to creating LMI’s as large as 2^n^2 by 2*n^2, for original n by n matrices. Thus, I cam see why you want to use SCS. But if bugs are occurring under CVX 3.0beta, the best alternative is likely to be the latest Mosek 9.3 under CVX 2.2.

Even if you got quantum_rel_entr to run without error messages under CVX 3.0beta, I wouldn’t trust the results, because there are several known instances of constraints being ignored under CVX 3.0beta, resulting in incorrect result, even though the solver and CVX claim the problem has been solved.

I also recommend you run without quiet option until you have everything running well. That way you can see all the solver and CVX output, which will help you diagnose and assess things.