[petsc-users] hypre support
Matthew Knepley
knepley at gmail.com
Fri May 16 14:13:13 CDT 2014
On Fri, May 16, 2014 at 1:55 PM, Dario Isola <dario.isola at newmerical.com>wrote:
> I was eventually able to make it run adopting a very small time-step
> (Courant number of about 1).
>
AMG is intended for elliptic systems.
Matt
> So either my problem is not well solved by AMG, as you said, or I am not
> using it very well.
>
> But I guess I should be able to take it from there.
>
> Thanks again for the support!
>
> Dario
>
>
> On 05/16/2014 01:56 PM, Barry Smith wrote:
>
>> Algebraic multigrid is not for everything.
>>
>> On May 16, 2014, at 11:49 AM, Dario Isola <dario.isola at newmerical.com>
>> 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 <dario.isola at newmerical.com>
>>>> 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
>>>>>
>>>>>
>
--
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
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