TAO Nonlinear Least-Squares integration

Hi everyone !

I’ve recently started using TAO to solve ill-posed problems, and I’d like to give a try to Tikhonov regularization methods. However, TAO least-squares solvers (TAO: Optimization Solvers — PETSc 3.21.0 documentation) are not yet supported (missing TaoSet(Jacobian)Residual() routines).

Do you think it would be possible to add these solvers to FreeFem TAO wrapper ?

If an alternative is already available, do not hesitate to mention it as well :slight_smile:

Thank you in advance for your help, and for your work in FreeFem !

Best regards,

Caroline.

It would be a very nice addition to the PETSc plugin in plugin/mpi/PETSc-code.hpp if you are willing to pitch in.