> On Sep 5, 2016, at 11:21 AM, Fande Kong <[email protected]> wrote: > > Hi Developers, > > There are two questions on the hypre preconditioner. > > (1) How to set different relax types on different levels? It looks to use the > SAME relax type on all levels except the coarse level which we could set it > to a different solver. Especially, could I set the smoother type on the > finest level as NONE?
I don't think this is possible through the PETSc interface; it may or may not be possible by adding additional hypre calls. You need to check the hypre documentation. > > (2) How could I know how many levels have been actually created in hypre, and > how many unknowns on different levels? The "-pc_view" can not tell me this > information: -pc_hypre_boomeramg_print_statistics integer different integers give different amounts of detail, I don't know what the integers mean. > > type: hypre > HYPRE BoomerAMG preconditioning > HYPRE BoomerAMG: Cycle type V > HYPRE BoomerAMG: Maximum number of levels 25 > HYPRE BoomerAMG: Maximum number of iterations PER > hypre call 1 > HYPRE BoomerAMG: Convergence tolerance PER hypre call > 0 > HYPRE BoomerAMG: Threshold for strong coupling 0.25 > HYPRE BoomerAMG: Interpolation truncation factor 0 > HYPRE BoomerAMG: Interpolation: max elements per row 0 > HYPRE BoomerAMG: Number of levels of aggressive > coarsening 0 > HYPRE BoomerAMG: Number of paths for aggressive > coarsening 1 > HYPRE BoomerAMG: Maximum row sums 0.9 > HYPRE BoomerAMG: Sweeps down 1 > HYPRE BoomerAMG: Sweeps up 1 > HYPRE BoomerAMG: Sweeps on coarse 1 > HYPRE BoomerAMG: Relax down > symmetric-SOR/Jacobi > HYPRE BoomerAMG: Relax up > symmetric-SOR/Jacobi > HYPRE BoomerAMG: Relax on coarse > Gaussian-elimination > HYPRE BoomerAMG: Relax weight (all) 1 > HYPRE BoomerAMG: Outer relax weight (all) 1 > HYPRE BoomerAMG: Using CF-relaxation > HYPRE BoomerAMG: Measure type local > HYPRE BoomerAMG: Coarsen type Falgout > HYPRE BoomerAMG: Interpolation type classical > linear system matrix = precond matrix: > > > > Fande,
