Dear Stefano, Very nice, that was exactly what I was looking for. Also the possibility of turning on adaptivity with MATIS seems an interesting option.
Best, Edoardo Il giorno gio 22 mag 2025 alle ore 10:33 Stefano Zampini < stefano.zamp...@gmail.com> ha scritto: > GDSW is algebraic, not restricted to DMDA. Here is an example command > line. > > -pc_type mg -pc_mg_levels 2 -pc_mg_adapt_interp_coarse_space *gdsw* > -pc_mg_galerkin -mg_levels_pc_type jacobi > > > If you have a MATIS matrix, you can also turn on adaptivity (see for > example these tests). > > > > https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/blob/main/src/ksp/ksp/tutorials/ex71.c*L727__;Iw!!G_uCfscf7eWS!Z06Y5N-tG2d-bTV_5UgqncaOVFzjv3GVertAowz01EIeSx2WIgHrNtv_gI26zxcuxrh6IaMuDaQe0Vx6FO3MYaMxOWXsQvfTFv9HGTisNCo$ > > > https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/blob/main/src/snes/tutorials/ex12.c*L1799__;Iw!!G_uCfscf7eWS!Z06Y5N-tG2d-bTV_5UgqncaOVFzjv3GVertAowz01EIeSx2WIgHrNtv_gI26zxcuxrh6IaMuDaQe0Vx6FO3MYaMxOWXsQvfTFv9HS314Dc0$ > > > > > Code setup is here > https://urldefense.us/v3/__https://gitlab.com/petsc/petsc/-/blob/main/src/ksp/pc/impls/mg/gdsw.c__;!!G_uCfscf7eWS!Z06Y5N-tG2d-bTV_5UgqncaOVFzjv3GVertAowz01EIeSx2WIgHrNtv_gI26zxcuxrh6IaMuDaQe0Vx6FO3MYaMxOWXsQvfTFv9H9bF7URM$ > > > > > > Il giorno gio 22 mag 2025 alle ore 10:59 Edoardo Centofanti < > edoardo.centofant...@universitadipavia.it> ha scritto: > >> 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!Z06Y5N-tG2d-bTV_5UgqncaOVFzjv3GVertAowz01EIeSx2WIgHrNtv_gI26zxcuxrh6IaMuDaQe0Vx6FO3MYaMxOWXsQvfTFv9HS4XKaQc$ >>> >>> <https://urldefense.us/v3/__https://petsc.org/release/manualpages/PC/PCMGSetAdaptCoarseSpaceType/__;!!G_uCfscf7eWS!ZDnv3udGFNlZEC_MRfLAqwvcvCObnaAjMCeyaW__UaecBvN3MkXrzOPwJJUSHXo80-xOQdLNnSf_nLmUd7bZxg$> >>> >>> Thanks, >>> Pierre >>> >>> Thank you in advance, >>> Best, >>> Edoardo >>> >>> >>> >> >> -- >> Edoardo Centofanti >> Dipartimento di Matematica 'Felice Casorati' >> Università degli Studi di Pavia >> >> Tel. 0382985608 | Ufficio A14 | Via Ferrata 5, 27100 Pavia, Italy >> <https://urldefense.us/v3/__https://maps.google.com/?q=Via*20Ferrata*205,*2027100*20Pavia,*20Italy__;JSUlJSU!!G_uCfscf7eWS!Zmi6sdgeoCOMy1lkVGYn-ac5wvH3QEcOkYQ2VzdQgCqLY8nIVkX1oi_yt5S2vJDcF5BT8mmzOLmOUEK483D0v9_aZe01iy1b20hMoN_kNHg$> >> > > > -- > Stefano > -- 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!Z06Y5N-tG2d-bTV_5UgqncaOVFzjv3GVertAowz01EIeSx2WIgHrNtv_gI26zxcuxrh6IaMuDaQe0Vx6FO3MYaMxOWXsQvfTFv9Ha7BdO-s$ >
