[petsc-users] [KSP] solveTranspose fails with Strumpack and SuperLU_dist

[Jean Marques]

Thank you very much for your inputs.

Matthew, this LS is a part of a rSVD algorithm (Halko et al, SIAM Review,
2009), hence I need to compute direct and adjoints system solutions.

Hong, that is the option I'll be using. I am explicitly setting a transpose
for now and this works (at a cost, as you said).

Barry, I'll also try this solution here, thanks!

Best,
Jean

On Sat, Apr 9, 2022 at 6:37 PM Barry Smith <bsmith at petsc.dev> wrote:

>
>   It would also be very straightforward for you to provide a merge request
> that adds support for PETSc to directly use SuperLU_DIST and Strumpacks
> transpose solver capability.   Just add the support to superlu_dist.c (and
> for strumpack) mimicking the style in mumps.c More specifically add a
>
> PetscErrorCode MatSolveTranspose_SuperLU_DIST(Mat A,Vec b,Vec x) function
> almost identical to MatSolveTranspose_MUMPS() but setting
>
>  Mat_SuperLU_DIST      *lu=(Mat_SuperLU_DIST*)A->data;
> lu->options.trans = TRANS;
>
> and register it where the solve is registered later in the file (seach for
> ops->solve)
>
> Detailed instructions on making a PETSc MR can be found at
> https://petsc.org/release/developers/integration/#getting-your-code-and-documentation-into-petsc
>
>
>
>
> On Apr 9, 2022, at 8:57 PM, Zhang, Hong via petsc-users <
> petsc-users at mcs.anl.gov> wrote:
>
> Jean,
>
> You can use -ksp_use_explicittranspose to make KSP transpose the system
> explicitly in the transposed solve. This option was designed to enable more
> choices of linear solvers and preconditions in adjoint solves, of course,
> at a cost.
>
> Hong (Mr.)
>
> On Apr 8, 2022, at 4:52 PM, Jean Marques <jeanmarques.eng at gmail.com>
> wrote:
>
> Hi all,
>
> This may be a naive question, and I hope this is the right place to ask
> about it.
> I need to solve a direct linear system with a sparse matrix R, then an
> adjoint system the hermitian of R.
>
> I use a petsc4py, so what I do is this:
> self.R.setUp()
> to set up the PETSc KSP variable R, then I do:
> self.R.solve(f, q)
> and later:
> self.R.solveTranspose(f, q)
>
> However, 'solveTranspose()' only works when I use MUMPS. If I try
> STRUMPACK or SUPERLU_DIST it fails, it seems that 'solveTranpose()' is not
> defined for them? or is there a specific way to call them with these
> libraries?
> Maybe the approach would be to define another 'self.R' variable but then
> set it as a transpose().conjugate() before setUp()?
> I was trying STRUMPACK because it has a low-memory approach and that's my
> main bottleneck.
>
> I appreciate any help you can provide.
>
> Best,
> Jean
>
> --
> *Jean Helder Marques Ribeiro*
> Ph.D. Candidate
> University of California, Los Angeles
> 420 Westwood Plaza, Los Angeles, CA 90095
> phone: (310) 689-6593
>
>
>
>

-- 
*Jean Helder Marques Ribeiro*
Ph.D. Candidate
University of California, Los Angeles
420 Westwood Plaza, Los Angeles, CA 90095
phone: (310) 689-6593
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20220411/955d141d/attachment.html>