On Wed, Mar 27, 2019 at 7:27 PM Matthew Knepley <[email protected]> wrote:
> On Fri, Mar 22, 2019 at 1:41 PM Swarnava Ghosh <[email protected]> > wrote: > >> Hi Mark and Matt, >> >> Thank you for your responses. >> "They may have elements on the unstructured mesh that intersect with any >> number of processor domains on the structured mesh. But the unstructured >> mesh vertices are in the structured mesh set of vertices" >> Yes, that is correct. We would want a vertex partitioning. >> > > Okay, I need to understand better what you want. A vertex partition of a > mesh does not make sense to me. What kind > of mesh do you have, and how do you plan to use the partitioned mesh? > I would guess they want a vertex partitioning to make an MatMPIAIJ. They could inject fine (structured) grid points into coarse (unstructured) points/vertices w/o communication. That's my best guess. > > Thanks, > > Matt > > >> Sincerely, >> Swarnava >> >> On Fri, Mar 22, 2019 at 4:08 PM Mark Adams <[email protected]> wrote: >> >>> Matt, >>> I think they want a vertex partitioning. They may have elements on the >>> unstructured mesh that intersect with any number of processor domains on >>> the structured mesh. But the unstructured mesh vertices are in the >>> structured mesh set of vertices. They want the partition of the >>> unstructured mesh vertices (ie, matrices) to be slaved to the partitioning >>> of the structured mesh. >>> Do I have that right Swarnava? >>> Mark >>> >>> On Fri, Mar 22, 2019 at 6:56 PM Matthew Knepley via petsc-users < >>> [email protected]> wrote: >>> >>>> On Thu, Mar 21, 2019 at 8:20 PM Swarnava Ghosh via petsc-users < >>>> [email protected]> wrote: >>>> >>>>> Dear PETSc users and developers, >>>>> >>>>> I am new to DMPLEX and had a query regarding setting up a consistent >>>>> domain decomposition of two meshes in PETSc. >>>>> I have a structured finite difference grid, managed through DMDA. I >>>>> have another unstructured finite element mesh managed through DMPLEX. Now >>>>> all the nodes in the unstructured finite element mesh also belong to the >>>>> set of nodes in the structured finite difference mesh (but not necessarily >>>>> vice-versa), and the number of nodes in DMPLEX mesh is less than the >>>>> number >>>>> of nodes in DMDA mesh. How can I guarantee a consistent domain >>>>> decomposition of the two meshes? By consistent, I mean that if a process >>>>> has a set of nodes P from DMDA, and the same process has the set of nodes >>>>> Q >>>>> from DMPLEX, then Q is a subset of P. >>>>> >>>> >>>> Okay, this is not hard. DMPlexDistribute() basically distributes >>>> according to a cell partition. You can use PetscPartitionerShell() to stick >>>> in whatever cell partition you want. You can see me doing this here: >>>> >>>> >>>> https://bitbucket.org/petsc/petsc/src/e2aefa968a094f48dc384fffc7d599a60aeeb591/src/dm/impls/plex/examples/tests/ex1.c#lines-261 >>>> >>>> Will that work for you? >>>> >>>> Thanks, >>>> >>>> Matt >>>> >>>> >>>>> I look forward to your response. >>>>> >>>>> Sincerely, >>>>> Swarnava >>>>> >>>>> >>>> >>>> -- >>>> 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/> >
