Sorry about the current mess but that page is halfway migrated, so any updates should go here: https://docs.petsc.org/en/main/install/externalsoftware_documentation/ <https://docs.petsc.org/en/main/install/externalsoftware_documentation/>
> Am 18.03.2021 um 15:22 schrieb Zhang, Hong via petsc-dev > <[email protected]>: > > Pierre, > This is an external package to petsc. Shall it be listed at > https://www.mcs.anl.gov/petsc/miscellaneous/external.html > <https://www.mcs.anl.gov/petsc/miscellaneous/external.html>? > PETSc: External Software - anl.gov > <https://www.mcs.anl.gov/petsc/miscellaneous/external.html> > PETSc interfaces to the following optional external software (installing > packages) (manual pages):. AMD - Approximate minimum degree orderings.; BLAS > and LAPACK; Chaco - a graph partitioning package.; ESSL - IBM's math library > for fast sparse direct LU factorization. FFTW - Fastest Fourier Transform in > the West, developed at MIT by Matteo Frigo and Steven G. Johnson. > www.mcs.anl.gov <http://www.mcs.anl.gov/> > Hong > From: Pierre Jolivet <[email protected]> > Sent: Thursday, March 18, 2021 1:16 AM > To: Zhang, Hong <[email protected]> > Cc: For users of the development version of PETSc <[email protected]> > Subject: Re: [petsc-dev] MatTransposeMatMult() bug > > https://www.sciencedirect.com/science/article/abs/pii/S0898122121000055 > <https://www.sciencedirect.com/science/article/abs/pii/S0898122121000055> > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/KSP/KSPHPDDM.html > > <https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/KSP/KSPHPDDM.html> > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCHPDDM.html > <https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCHPDDM.html> > I need to update the PETSc user manual though, specifically with respect to > systems with multiple right-hand sides. > But don’t worry, Stefano has sorted the bug out, which was due to a faulty > MatSetFromOptions() in MatMAIJ, used by MatTransposeMatMult(). > > Thanks, > Pierre > >> On 17 Mar 2021, at 11:21 PM, Zhang, Hong <[email protected] >> <mailto:[email protected]>> wrote: >> >> What is hpddm? I do not see its document. >> Hong >> >> From: Matthew Knepley <[email protected] <mailto:[email protected]>> >> Sent: Wednesday, March 17, 2021 2:49 PM >> To: Zhang, Hong <[email protected] <mailto:[email protected]>> >> Cc: Pierre Jolivet <[email protected] <mailto:[email protected]>>; For users of >> the development version of PETSc <[email protected] >> <mailto:[email protected]>> >> Subject: Re: [petsc-dev] MatTransposeMatMult() bug >> >> On Wed, Mar 17, 2021 at 3:27 PM Zhang, Hong via petsc-dev >> <[email protected] <mailto:[email protected]>> wrote: >> Pierre, >> Do you mean a possible bug in C=AtB MatTransposeMatMult()? >> Can you provide a stand-alone test without hpddm that reproduces this error? >> >> Hong, you should be able to just configure with --download-hpddm and then >> run that ex76 test. >> >> Thanks, >> >> Matt >> >> Hong >> From: petsc-dev <[email protected] >> <mailto:[email protected]>> on behalf of Pierre Jolivet >> <[email protected] <mailto:[email protected]>> >> Sent: Wednesday, March 17, 2021 4:31 AM >> To: For users of the development version of PETSc <[email protected] >> <mailto:[email protected]>> >> Subject: [petsc-dev] MatTransposeMatMult() bug >> >> Hello, >> While trying out Stefano’s PCApplyMat_MG() code (*), we stumbled upon weird >> numerical errors when reusing a Mat for both MatProduct_AB and >> MatProduct_AtB. >> This reminded me that there has been a long-standing issue with >> MatTransposeMatMult(), see >> https://www.mcs.anl.gov/petsc/petsc-current/src/ksp/pc/impls/hpddm/hpddm.cxx.html#line608 >> >> <https://www.mcs.anl.gov/petsc/petsc-current/src/ksp/pc/impls/hpddm/hpddm.cxx.html#line608>, >> that I never looked into. >> I’ve now been trying to figure this out, because this has side effects in >> multiple places (PCMG and PCHPDDM at least), and thus could impact user-code >> as well? >> With this commit: >> https://gitlab.com/petsc/petsc/-/commit/03d8bd538039defc2fcc3e37d523735c4aaceba0 >> >> <https://gitlab.com/petsc/petsc/-/commit/03d8bd538039defc2fcc3e37d523735c4aaceba0> >> + >> $ mpirun -n 4 src/ksp/ksp/tutorials/ex76 -ksp_converged_reason -pc_type >> hpddm -pc_hpddm_levels_1_eps_nev 20 -ksp_type preonly -mat_type aij >> -load_dir ${DATAFILESPATH}/matrices/hpddm/GENEO -rhs 2 >> -pc_hpddm_coarse_correction balanced -C_input_mattransposematmult >> -D_output_mattransposematmult >> I’m seeing that C is nonzero, but D is full of zeros. >> Mat Object: 4 MPI processes >> type: mpidense >> 5.7098316584361917e-08 1.0159399260517841e-07 >> 1.5812349976211856e-07 2.0688121715350138e-07 >> 2.4887556933361981e-08 4.8111092300772958e-08 >> 1.4606298643602107e-07 1.7213611729839211e-07 >> […] >> Mat Object: 4 MPI processes >> type: mpidense >> 0.0000000000000000e+00 0.0000000000000000e+00 >> 0.0000000000000000e+00 0.0000000000000000e+00 >> 0.0000000000000000e+00 0.0000000000000000e+00 >> 0.0000000000000000e+00 0.0000000000000000e+00 >> […] >> >> If one switches to a MatType which has no MatProduct_AtB implementation with >> B of type MPIDense (reminder: in that case, the product is computed >> column-by-column), e.g., -mat_type sbaij, one gets the expected result. >> Mat Object: 4 MPI processes >> type: mpidense >> 7.2003197398135299e-01 9.5191869895699011e-01 >> 6.1793966541680234e-02 9.3884397585488877e-01 >> 1.0022337823233585e-02 2.4653068080134588e-01 >> 1.4463931936094099e-01 8.6111517670701687e-01 >> >> Is there a bug somewhere with the MatAIJ implementation, or am I doing >> something which is not allowed by the MatProduct() machinery? >> >> Thanks, >> Pierre >> >> (*) https://gitlab.com/petsc/petsc/-/merge_requests/3717 >> <https://gitlab.com/petsc/petsc/-/merge_requests/3717> >> >> >> -- >> 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 >> >> https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
