Jed, thank you for your perspective. I can certainly try BoomerAMG on our
problem. I'm also going to try pARMS for variance of ILU.
Glenn, I think I need to first work on restructure of the matrix and then
scaling.
- Heeho Daniel Park
On 3/5/19, 11:34 PM, "Jed Brown" <j...@jedbrown.org> wrote:
Yeah, I wouldn't get bogged down in that. I would work on the good
methods and then use as a reference those components without the
composition. For example, you might use Hypre's BoomerAMG inside a
composed preconditioner. You could run it on its own to show that the
chosen structure was important.
"Hammond, Glenn E" <geha...@sandia.gov> writes:
> Jed,
>
> For the proposal, Heeho wants to demonstrate that a (well?) tuned black
box preconditioner does not perform well (e.g. ILU[k], ILU[dt]). Ultimately,
he plans to build on work by Qang Bui (currently a post-doc at LLNL), which is
aligned with what you propose below, e.g.
>
> Bui, Quan & Wang, Lu & Osei-Kuffuor, Daniel. (2018). Algebraic Multigrid
Preconditioners for Two-phase Flow in Porous Media with Phase Transitions.
Advances in Water Resources. 114. 10.1016/j.advwatres.2018.01.027.
> Bui, Quan & C. Elman, Howard & Moulton, J. (2016). Algebraic Multigrid
Preconditioners for Multiphase Flow in Porous Media. SIAM Journal on Scientific
Computing. 39. 10.1137/16M1082652.
>
> So, at this point, Heeho is looking for the best out-of-the-box
preconditioners to demonstrate their poor performance. Or perhaps he should
just employ PETSc's ILU[k] and move on....
>
> Glenn
>
>> -----Original Message-----
>> From: Jed Brown <j...@jedbrown.org>
>> Sent: Tuesday, March 5, 2019 9:06 PM
>> To: Park, Heeho <heep...@sandia.gov>; petsc-dev@mcs.anl.gov
>> Cc: Park, Heeho Daniel <hdpa...@illinois.edu>; Hammond, Glenn E
>> <geha...@sandia.gov>
>> Subject: [EXTERNAL] Re: [petsc-dev] external preconditioner availablilty
for
>> PETSc
>>
>> From a research perspective, it doesn't make sense to view these
>> preconditioners as black boxes. Your problem will likely have an
elliptic
>> component (which you might approach using a multilevel method such as
>> PCGAMG, PCML, PCHYPRE, or PCBDDC, all of which can accept some
>> problem-specific input information as well as tunable parameters)
combined
>> (perhaps using PCFIELDSPLIT) with a transport solver (perhaps one-level
>> domain decomposition). The details of the splits will take some thought
and
>> you'll want to compare to monolithic (unsplit) 1-level domain
decomposition
>> methods with suitably chosen subdomains and/or geometric multigrid. One
>> way to start would be to do a literature search and try to reproduce the
>> results from some methods in the literature. After that, you'll have a
>> baseline for comparison and probably get some ideas about composition.
>>
>> "Park, Heeho via petsc-dev" <petsc-dev@mcs.anl.gov> writes:
>>
>> > Hi PETSc developers,
>> >
>> > I’m writing my proposal for my dissertation research at UIUC that will
study
>> on effectiveness of preconditioners for anisothermal, multiphase porous
>> media flow calculations in parallel using PFLOTRAN. I know the link
below lists
>> preconditioners but from your experience, which preconditioning packages
>> provide reliable and efficient PILUT, AMG, SA-AMG preconditioners for
>> PETSc and do you have other preconditioner recommendations?
>> > I used hypre PILUT, but the performance and the linear iteration count
to
>> solve a matrix is worse than ILU(0) which is not what I expected.
>> >
>> > https://www.mcs.anl.gov/petsc/documentation/linearsolvertable.html
>> >
>> > Heeho Daniel Park
>> >
>> > ! ------------------------------------ !
>> > Sandia National Laboratories
>> > Org: 08844, R&D
>> > Work: 505-844-1319
>> > ! ------------------------------------ !
