I am a newcomer to Petsc non-linear capabilities, so far implementing such things myself, only delegating linear solves to Petsc.
I want to start small by porting a very simple code using fixed point iterations as follows: A(x)x = b(x) is approximated as A(x0)x = b(x0), then solved by KSP for x, then x0 is updated to x, then repeat until convergence. In the documentation chapter 5 I see all sorts of sophisticated Newton type methods, requiring computation of the Jacobian. Is the above defined simple method still accessible somehow in Petsc or such triviality can only be done by hand? Which one from the existing nonlinear solvers would be a closest match both in simplicity and robustness (even if slow performance)? Regards, Dominik
