The sequential SuperLU has ILUTP implementation, not in parallel versions. PETSc already supports the option of using SuperLU.
In SuperLU distribution: EXAMPLE/zitersol.c : an example to use GMRES with ILUTP preconditioner (returned from driver SRC/zgsisx.c) SRC/zgsitrf.c : the actual ILUTP factorization routine Sherry Li On Wed, Oct 30, 2013 at 8:48 AM, Matthew Knepley <[email protected]> wrote: > On Wed, Oct 30, 2013 at 8:58 AM, Torquil Macdonald Sørensen < > [email protected]> wrote: > >> Thanks Matthew! >> >> The problem I'm working on is the Dirac equation, in various number of >> dimensions. I'm going to take a stab at multigrid preconditioning. >> > > My limited knowledge of the Dirac Equation tells me that it is a > relativistic wave equation, and thus hyperbolic, which is quite difficult > for > MG (but doable with a bunch of work). How do you have this formulated? > > Thanks, > > Matt > > >> Best regards >> Torquil Sørensen >> >> >> On 27 October 2013 14:48, Matthew Knepley <[email protected]> wrote: >> >>> On Sat, Oct 26, 2013 at 3:05 PM, Torquil Macdonald Sørensen < >>> [email protected]> wrote: >>> >>>> Hi! >>>> >>>> I have a linear problem Ax=b, with complex values, that is solved very >>>> well using the ILUTP and GMRES implementations in GMM++. None of the other >>>> preconditioners available in GMM++ would work (e.g. ILU and ILUT) for this >>>> problem. >>>> >>>> Then I tried the same problem using ILU and GMRES in PETSc, with no >>>> success, despite a lot of attempts at adjusting ILU settings. I always end >>>> up with gigantic residual norm values. The same PETSc program works well >>>> when I apply it to a different matrix A. >>>> >>>> I'm now suspecting that the ILU options cannot be set so as to obtain >>>> ILUTP behaviour. >>>> >>>> What would be the recommended method to access an ILUTP preconditioner >>>> from PETSc? >>>> >>>> According to the PETSc website, a preconditioner named ILUDT is >>>> available by using the external package Hypre, but I had to deselect Hypre >>>> during the PETSc build due to my use of complex numbers... So do you guys >>>> think that I should transform everything to a real representation and try >>>> Hypre/ILUDT? >>>> >>> >>> I suggest you look for a different preconditioner. The fact that you >>> have so much trouble reproducing the behavior shows >>> you just how fragile the performance of ILU is. It may work for a >>> certain size, but fail for larger or smaller problems, or slightly >>> different parameters. What problem are you solving? Usually the best >>> option is to consult the literature for preconditioners >>> tailored to your problem, and then reproduce them. >>> >>> Matt >>> >>> >>>> Best regards >>>> Torquil Sørensen >>>> >>>> >>> >>> >>> -- >>> 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 >>> >> >> > > > -- > 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 >
