[petsc-dev] [EXTERNAL] Re: external preconditioner availablilty for PETSc

[Park, Heeho]

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" <jed at 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" <gehammo at 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 <jed at jedbrown.org>
    >> Sent: Tuesday, March 5, 2019 9:06 PM
    >> To: Park, Heeho <heepark at sandia.gov>; petsc-dev at mcs.anl.gov
    >> Cc: Park, Heeho Daniel <hdpark2 at illinois.edu>; Hammond, Glenn E
    >> <gehammo at 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 at 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
    >> > ! ------------------------------------ !