You can call PCSetType(pc,PCILU); KSPSetFromOptions(ksp); PCFactorSetMatOrderingType(pc,....);
This reproduces the old behavior in PETSc. You can still pass -pc_type somethingelse at runtime to use a different PC. > On Aug 18, 2024, at 6:19 PM, Zou, Ling <l...@anl.gov> wrote: > > Thank you, Barry. You must be right in this case. I am defaulting to ILU. > I did an additional test to confirm, with ‘-pc_type ilu’ in the command line, > it works fine. > > If I am defaulting to ILU, when should I call PCFactorSetMatOrderingType? > > -Ling > > > From: Barry Smith <bsm...@petsc.dev <mailto:bsm...@petsc.dev>> > Date: Sunday, August 18, 2024 at 12:22 PM > To: Zou, Ling <l...@anl.gov <mailto:l...@anl.gov>> > Cc: petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov> > <petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov>> > Subject: Re: [petsc-users] PCFactorSetMatOrderingType not working with 3.21 > > Are you using -pc_type ilu at the command line in your test? Or just letting > it default to using ILU? This could explain the difference, the decision of > what preconditioner to default to has moved until later in code, not when the > PC is created > ZjQcmQRYFpfptBannerStart > This Message Is From an External Sender > This message came from outside your organization. > > ZjQcmQRYFpfptBannerEnd > > Are you using -pc_type ilu at the command line in your test? Or just > letting it default to using ILU? > > This could explain the difference, the decision of what preconditioner to > default to has moved until later in code, not when the PC is created or the > matrix supplied but when it starts to build the preconditioner. Hence when > you call PCFactorSetMatOrderingType() in the code the PC may not yet be set > to ILU (or anything) hence the PCFactorSetMatOrderingType() is ignored, > > > > > On Aug 17, 2024, at 3:44 PM, Zou, Ling <l...@anl.gov <mailto:l...@anl.gov>> > wrote: > > Barry, thanks. > I am accessing PETSc through MOOSE. I need to figure out if the versions are > consistent and how to test it. > -Ling > > From: Barry Smith <bsm...@petsc.dev <mailto:bsm...@petsc.dev>> > Date: Saturday, August 17, 2024 at 12:08 PM > To: Zou, Ling <l...@anl.gov <mailto:l...@anl.gov>> > Cc: petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov> > <petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov>> > Subject: Re: [petsc-users] PCFactorSetMatOrderingType not working with 3.21 > > I have attached src/snes/tutorials/ex5. c in which I tried to reproduce your > problem by inserting the code you've indicated. However I am not getting the > problem you see, I am seeing, type: ilu out-of-place factorization 0 levels > of fill tolerance > ZjQcmQRYFpfptBannerStart > This Message Is From an External Sender > This message came from outside your organization. > > ZjQcmQRYFpfptBannerEnd > > I have attached src/snes/tutorials/ex5.c in which I tried to reproduce > your problem by inserting the code you've indicated. > > However I am not getting the problem you see, I am seeing, > > type: ilu > out-of-place factorization > 0 levels of fill > tolerance for zero pivot 2.22045e-14 > matrix ordering: rcm > > > when I run with -pc_type ilu -snes_view > > Can you please confirm you get the same problem with the attached ex5.c ? > You could send your code to see if I can reproduce the problem. > > I am using the release branch of PETSc > > Barry > > > > > > > > > > On Aug 17, 2024, at 12:35 PM, Zou, Ling via petsc-users > <petsc-users@mcs.anl.gov <mailto:petsc-users@mcs.anl.gov>> wrote: > > Hi all, > > The following codes are how I used to setup PC mat ordering: > > // Setup KSP/PC (at this moment, user-input options and commandline options > are available) > SNESGetKSP(snes, &ksp); > KSPSetFromOptions(ksp); > PC pc; > KSPGetPC(ksp, &pc); > PCFactorSetMatOrderingType(pc, MATORDERINGRCM); > // PCFactorSetLevels(pc, 5); > SNESSetFromOptions(snes); > > After switching to PETSc 3.21, this no longer works, and can be confirmed > from ‘-snes_view’ output: > > PC Object: 1 MPI process > type: ilu > out-of-place factorization > 0 levels of fill > tolerance for zero pivot 2.22045e-14 > using diagonal shift to prevent zero pivot [NONZERO] > matrix ordering: natural > > The command line option still works, i.e., ‘-pc_factor_mat_ordering_type rcm’ > gives me the correct behavior. > > Questions: > Is this a bug introduced in the new version, or > With the new version, I should call this function at a different time? > > Best, > > -Ling
