On Sun, Jun 18, 2023 at 2:21 PM YuSh Lo <[email protected]> wrote:
> Hi Matthew, > > Yes, I have called DMPlexDistribute(). > > so what I do is: > > CALL DMSetUseNatural(serialDM, PETSC_TRUE, errorCode) > CALL DMPlexDistribute(serialDM, 0, migrationSF, distributedDM, errorCode) > CALL DMPlexGetGlobalToNaturalSF(serialDM, naturalSF, errorCode) > CALL PetscSFView(naturalSF, PETSC_VIEWER_STDOUT_WORLD, errorCode) > > The naturalSF is null. > You can see here: https://gitlab.com/petsc/petsc/-/blob/main/src/dm/impls/plex/plexdistribute.c#L1836 that the natural SF is created when you distribute. Are you running in serial? https://gitlab.com/petsc/petsc/-/blob/main/src/dm/impls/plex/plexdistribute.c#L1715 No SF is created in serial because we do not reorder unless distributing. Thanks, Matt > Thanks, > Josh > > > > Matthew Knepley <[email protected]> 於 2023年6月18日 週日 上午7:42寫道： > >> On Sun, Jun 18, 2023 at 2:12 AM YuSh Lo <[email protected]> wrote: >> >>> I am getting a null PetscSF after calling DMPlexGetGlobalToNatural >>> >> >> Did you call DMDIstribute()? This is where the map is created because >> until then, the map is identity. >> >> Thanks, >> >> Matt >> >> >>> YuSh Lo <[email protected]> 於 2023年6月18日 週日 上午12:18寫道： >>> >>>> Hi Matthew, >>>> >>>> After setting DMSetUseNatural to true and calling >>>> DMPlexGetGlobalToNatural, >>>> I call PestcSFView right away, it gives segmentation fault. >>>> I have also tried DMGetNaturalSF, it also gives segmentation fault when >>>> calling PetscSFView. >>>> I use PETSC_VIEWER_STDOUT_WORLD as PetscViewer >>>> >>>> Thanks, >>>> Josh >>>> >>>> >>>> Matthew Knepley <[email protected]> 於 2023年6月9日 週五 下午1:04寫道： >>>> >>>>> On Fri, Jun 9, 2023 at 1:46 PM YuSh Lo <[email protected]> wrote: >>>>> >>>>>> Hi Barry, >>>>>> >>>>>> Is there any way to use the mapping generated by DMPlexDistribute >>>>>> along with AO? >>>>>> >>>>> >>>>> For Plex, if you turn on >>>>> >>>>> https://petsc.org/main/manualpages/DM/DMSetUseNatural/ >>>>> >>>>> before DMPlexDistribute(), it will compute and store a GlobalToNatural >>>>> map. This can be >>>>> used to map vectors back and forth, but you can extract the SF >>>>> >>>>> DMPlexGetGlobalToNaturalSF >>>>> <https://petsc.org/main/manualpages/DMPlex/DMPlexGetGlobalToNaturalSF/> >>>>> >>>>> and use that to remap your IS, by extracting the indices. >>>>> >>>>> THanks, >>>>> >>>>> Matt >>>>> >>>>> >>>>>> Thanks, >>>>>> Josh >>>>>> >>>>>> >>>>>> Barry Smith <[email protected]> 於 2023年6月9日 週五 上午10:42寫道： >>>>>> >>>>>>> >>>>>>> You might be looking for >>>>>>> https://petsc.org/release/manualpages/AO/AO/#ao >>>>>>> >>>>>>> >>>>>>> On Jun 9, 2023, at 11:02 AM, Mark Adams <[email protected]> wrote: >>>>>>> >>>>>>> An IS is just an array of integers. We need your context. >>>>>>> Is this question for sparse matrices? If so look at the >>>>>>> documentation on the AIJ matrix construction and the global vertex >>>>>>> numbering system. >>>>>>> >>>>>>> Mark >>>>>>> >>>>>>> On Thu, Jun 8, 2023 at 1:15 PM YuSh Lo <[email protected]> wrote: >>>>>>> >>>>>>>> Hi, >>>>>>>> >>>>>>>> I have an IS that contains some vertex that is in natural >>>>>>>> numbering. How do I map them to global numbering without being >>>>>>>> distributed? >>>>>>>> >>>>>>>> Thanks, >>>>>>>> Josh >>>>>>>> >>>>>>> >>>>>>> >>>>> >>>>> -- >>>>> 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/> >>>>> >>>> >> >> -- >> 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/> >> > -- 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/>
