[petsc-users] PCFactorSetMatOrderingType not working with 3.21

[Zou, Ling via petsc-users]

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