Algebraic multigrid is not for everything. On May 16, 2014, at 11:49 AM, Dario Isola <[email protected]> wrote:
> Thanks a lot for your answers. > > I ran it with > -ksp_type gmres -pc_type hypre -pc_hypre_type euclid > and it worked very well. Thanks. > > I then tried to use boomeramg as a preconditioner coupled with Richardson but > I was not successful, it failed to solve the system and returned nans. > -ksp_type richardson -pc_type hypre -pc_hypre_type boomeramg > -pc_hypre_boomeramg_relax_type_all SOR/Jacobi -pc_hypre_boomeramg_print_debug > -ksp_view -ksp_monitor_true_residual > and i got the following > > ===== Proc = 0 Level = 0 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 18308 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 7 nc_offd = 0 > > ===== Proc = 0 Level = 1 ===== > Proc = 0 Coarsen 1st pass = 0.010000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 8725 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 16 nc_offd = 0 > > ===== Proc = 0 Level = 2 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 4721 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 13 nc_offd = 0 > Proc = 0 iter 3 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 4 nc_offd = 0 > > ===== Proc = 0 Level = 3 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 2495 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 22 nc_offd = 0 > Proc = 0 iter 3 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 4 nc_offd = 0 > > ===== Proc = 0 Level = 4 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 1337 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 13 nc_offd = 0 > Proc = 0 iter 3 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 2 nc_offd = 0 > > ===== Proc = 0 Level = 5 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 695 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 3 nc_offd = 0 > > ===== Proc = 0 Level = 6 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 343 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 21 nc_offd = 0 > Proc = 0 iter 3 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 2 nc_offd = 0 > > ===== Proc = 0 Level = 7 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 174 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 15 nc_offd = 0 > Proc = 0 iter 3 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 2 nc_offd = 0 > > ===== Proc = 0 Level = 8 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 81 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 13 nc_offd = 0 > > ===== Proc = 0 Level = 9 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 37 nc_offd = 0 > Proc = 0 iter 2 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 6 nc_offd = 0 > > ===== Proc = 0 Level = 10 ===== > Proc = 0 Coarsen 1st pass = 0.000000 > Proc = 0 Coarsen 2nd pass = 0.000000 > Proc = 0 Initialize CLJP phase = 0.000000 > Proc = 0 iter 1 comm. and subgraph update = 0.000000 > Proc = 0 CLJP phase = 0.000000 graph_size = 11 nc_offd = 0 > > > 0 KSP preconditioned resid norm 7.299769365830e+14 true resid norm > 8.197927963033e-03 ||r(i)||/||b|| 1.000000000000e+00 > 1 KSP preconditioned resid norm 2.319459389445e+28 true resid norm > 6.152576199945e+12 ||r(i)||/||b|| 7.505038136086e+14 > KSP Object: 1 MPI processes > type: richardson > Richardson: damping factor=1 > maximum iterations=90, initial guess is zero > tolerances: relative=0.1, absolute=1e-50, divergence=100000 > left preconditioning > using PRECONDITIONED norm type for convergence test > PC Object: 1 MPI processes > 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 SOR/Jacobi > HYPRE BoomerAMG: Relax up 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: > Matrix Object: 1 MPI processes > type: seqbaij > rows=22905, cols=22905, bs=5 > total: nonzeros=785525, allocated nonzeros=785525 > total number of mallocs used during MatSetValues calls =0 > block size is 5 > Do you guys have any suggestion? Is it possible that I am haven't > initialized boomeramg properly? Or it is just my system equations that can > not be solved by AMG? > > Sincerely, > Dario > > > > > On 05/16/2014 11:54 AM, Barry Smith wrote: >> On May 16, 2014, at 10:46 AM, Dario Isola <[email protected]> >> wrote: >> >> >>> Dear all, >>> >>> I am investigating the use of hypre+petsc. I was able to successfully >>> configure, install, compile petsc 3.3 with the external package for hypre. >>> >>> I tried to run it with the following options >>> -pc_type hypre -pc_type_hypre pilut -ksp_type richardson >>> and, although he did not complain, it does not solve the system either. >>> >> Do you meaning it did not converge? At first always run with -ksp_view >> (or -snes_view if using snes or -ts_view if using ts) and >> -ksp_monitor_true_residual to see what is going on. >> >> >>> -pc_type_hypre pilut >>> >> is wrong it is -pc_hypre_type pilut >> >> Note that pilut will generally not work with Richardson you need a “real” >> Krylov method like GMRES. >> >> Also the ilu type preconditioners don’t scale particularly well though >> occasionally they can be fine. >> >> >>> To what extent is hypre supported by petsc? More specifically, what kind of >>> matrices? >>> >> If it cannot handle the matrix type it would give an error message. >> Hypre uses a format like AIJ so you should use AIJ. Note that you can make >> the matrix type a runtime option so you don’t have to compile in that it is >> BAIJ. >> >> >> >>> I am using a baij matrix. >>> >>> Thanks in advance, >>> D >>> >
