Re: [petsc-users] distribute and cells mapping.

[Olivier Bonnefon]

On 08/23/2013 04:42 PM, Matthew Knepley wrote:
On Fri, Aug 23, 2013 at 9:35 AM, Olivier Bonnefon 
<olivier.bonne...@avignon.inra.fr 
<mailto:olivier.bonne...@avignon.inra.fr>> wrote:

    Hello,

    Thanks for your answers, I'm now able to import and distribute a mesh:


You might simplify this to

if (rank) {obNbCells = 0; obNbVertex = 0;}
ierr = 
DMPlexCreateFromCellList(comm,dim,obNbCells,obNbVertex,3,0,obCells,2,obVertex,dm);CHKERRQ(ierr);

    if (!rank){
            ierr =
    
DMPlexCreateFromCellList(comm,dim,obNbCells,obNbVertex,3,0,obCells,2,obVertex,dm);CHKERRQ(ierr);
             for (i=0;i<obNbBound;i++){
               ierr =DMPlexSetLabelValue(*dm, "marker",
    obBoundary[i]+obNbCells, 1);CHKERRQ(ierr);
             }
    }else {
              ierr =
    
DMPlexCreateFromCellList(comm,dim,0,0,3,0,obCells,2,obVertex,dm);CHKERRQ(ierr);
    }

    ierr = DMPlexDistribute(*dm, partitioner, 0,
    &distributedMesh);CHKERRQ(ierr);
    if (distributedMesh) {
          ierr = DMDestroy(dm);CHKERRQ(ierr);
          *dm  = distributedMesh;
    }

    Is it possible to known the resulting partition ? ie, What is the
    mapping between the initial cell number and the local cell (used
    in DMPlexComputeResidualFEM)?
    I need this to write an efficient implementation of the FEM struct
    functions f0 and g0, space depending.


Yes, but I really do not think you want to do things that way. I am 
assuming you want different material models or something
in different places. The way I envision that is using a DMLabel to 
mark up parts of the domain. All labels are automatically
distributed with the mesh. Is that what you want?
Hello,

It is exactly what I need: I'm mobilized a landscape, and the parameters 
of the model depend of the type of crop. Therefore, I have created a 
label for each type of crop and I have labeled each triangle with the 
corresponding label:

 for (i=0;i<obNbCells;i++){
     if (labelCells[i]==1){
        ierr =DMPlexSetLabelValue(*dm, "marker1", i, 1);CHKERRQ(ierr);
     }else{
        ierr =DMPlexSetLabelValue(*dm, "marker2", i, 1);CHKERRQ(ierr);
     }
 }

So, I'm able to mark the triangles, but I'm not able to get this label 
in the plugin "fem.f0Funcs" and "fem.g0Funcs": These plugins are called 
by looping on the triangles in the function "FEMIntegrateResidualBatch", 
but the dm is not available, so I can't use the functions 
DMPlexGetLabel, DMLabelGetStratumSize and DMLabelGetStratumIS. What is 
the good way to get the labels in the user plugins of the fem struct ?


Thanks a lot for your help.

Olivier B

  Thanks,

     Matt

    Regards,

    Olivier B

    -- 
    Olivier Bonnefon
    INRA PACA-Avignon, Unité BioSP
    Tel: +33 (0)4 32 72 21 58 <tel:%2B33%20%280%294%2032%2072%2021%2058>




--
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


--
Olivier Bonnefon
INRA PACA-Avignon, Unité BioSP
Tel: +33 (0)4 32 72 21 58