Consider a potential/poisson equation on a very large, complicated geometry. Currently, an self-written FEM and linear solvers from NumPy are used. Performance is, of course, not good enough for larger problems.
I'd like to switch to PETSc and use algebraic multigrid preconditioners. Surprisingly, I could not find good documentation or examples on algebraic multigrid in PETSc. Are there any good examples? Or is it maybe to early to use algebraic multigrid, if I don't want to go into development too deep?
(This question is mainly intended to find more documentation about algebraic multigrid in PETSc, but please let me know if my approach is generally a bad idea.)