Log convex error


My objective function is log2(x^2+1+x) which is a quasiconvex function. How can I write this objective in CVX? I get Disciplined convex programming error: Illegal operation: log( {convex} ).


It’s neither convex nor concave over the entirety of its natural domain. So I think you’re out of luck with CVX. But if someone knows better, let them post.

Hello Mark,

Thanks for you reply. It is true that this function is neither convex nor concave. But it is a quasi convex function!.

But it is not good enough that it is quasi convex. It must be convex if you want to use cvx.

Oh! Thank you, Erling.