[petsc-users] fixed point interations

[Dominik Szczerba]

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