Dear all, Thank you for your answers. Do you know which options are required for a typical use case of GDSW in PCMG? However, I imagine that only structured DMDA meshes can be employed with it.
Best, Edoardo Il giorno mer 21 mag 2025 alle ore 16:52 Barry Smith <bsm...@petsc.dev> ha scritto: > > Thanks for your interest in this type of algorithm. > > As Pierre notes, the code is implemented only as a simple tutorial on > one particular "exotic" wire basket-type algorithm. We don't recommend this > implementation for more general algorithms or geometries. > > The face dof represents some sort of "average" of the face solution, it > is not a point value. > > Barry > > > On May 21, 2025, at 4:51 AM, Pierre Jolivet <pie...@joliv.et> wrote: > > > > On 21 May 2025, at 10:41 AM, Edoardo Centofanti < > edoardo.centofant...@universitadipavia.it> wrote: > > > Dear all, > > I have some questions about the PCEXOTIC preconditioner: > > 1- While the type "wirebasket" seems clear to me, I do not understand what > is meant as "one dof per face" in the documentation referring to "face" > type. Is it intended as the interpolation on the centre of the face or some > mean value? > > 2- Is it possible to change the overlap between the subdomains? > > 3- Are there any plans of extending the implementation to unstructured > grids (DMPlex-like)? The current one seems to rely heavily on DMDA > > 4- Running some preliminary tests on GPU with a code of mine that works on > CPU, I got the following error: > > ** On entry to cusparseSpMM_bufferSize(): dimension mismatch, > matA.num_rows (15405) != matC.num_rows (44955) with opA = > CUSPARSE_OPERATION_NON_TRANSPOSE > > Is the preconditioner intended to run also on GPU or the error above comes > from the fact that this feature has yet to be tested/fully implemented? > > > This preconditioner is very old and the code is barely maintained. > There is a newer implementation of the GDSW preconditioner in PCMG, see > https://urldefense.us/v3/__https://petsc.org/release/manualpages/PC/PCMGSetAdaptCoarseSpaceType/__;!!G_uCfscf7eWS!Zmi6sdgeoCOMy1lkVGYn-ac5wvH3QEcOkYQ2VzdQgCqLY8nIVkX1oi_yt5S2vJDcF5BT8mmzOLmOUEK483D0v9_aZe01iy1b20hMB1HPuOE$ > > <https://urldefense.us/v3/__https://petsc.org/release/manualpages/PC/PCMGSetAdaptCoarseSpaceType/__;!!G_uCfscf7eWS!ZDnv3udGFNlZEC_MRfLAqwvcvCObnaAjMCeyaW__UaecBvN3MkXrzOPwJJUSHXo80-xOQdLNnSf_nLmUd7bZxg$> > > Thanks, > Pierre > > Thank you in advance, > Best, > Edoardo > > > -- Edoardo Centofanti Dipartimento di Matematica 'Felice Casorati' Università degli Studi di Pavia Tel. 0382985608 | Ufficio A14 | Via Ferrata 5, 27100 Pavia, Italy <https://urldefense.us/v3/__https://maps.google.com/?q=Via*20Ferrata*205,*2027100*20Pavia,*20Italy__;JSUlJSU!!G_uCfscf7eWS!Zmi6sdgeoCOMy1lkVGYn-ac5wvH3QEcOkYQ2VzdQgCqLY8nIVkX1oi_yt5S2vJDcF5BT8mmzOLmOUEK483D0v9_aZe01iy1b20hMoN_kNHg$ >
