Hi PETSc users, I was looking for the exact definitions of the threshold parameter (-pc_gamg_threshold) for gamg and of the strong threshold (-pc_hypre_boomeramg_strong_threshold) for Hypre BoomerAMG. My curiosity comes from the fact that the suggested parameters (apparently acting on the same aspect of the algorithms) differ of around one order of magnitude (if I remember right from the PETSc manual, the gamg threshold for 3D problems is around 0.05, while for boomerAMG ranges from 0.25 to 0.5).
Thank you in advance, Edoardo
