Provide interface for partitioning locally connected faces

[prudhomm]

For some PDEs we have to deal with constant functions (scalar or vectorial). They have usually local support associated to one or several physical face markers for example in integral boundary conditions or when modeling rigid body motion. In order to accomodate the fact that these functions usually couple the degrees of freedom associated to some other discretisation, it may be beneficial to have the elements associated to the faces where the constant functions are defined to be neighbors of each others in order to avoid MPI communication and improve scalability

update feelpp_mesh_partitioner documentation

here is a command line

 ./feelpp_mesh_partitioner --json cases/three-spheres-part.json --ifile cases/three-spheres.geo  --part 24

and to export to paraview

mpirun -np 24 ./feelpp_mesh_exporter --gmsh.filename three-spheres_p24.json

[romainhild]

@prudhomm is there an example somewhere as to how to use the partitioner now ?

[prudhomm]

here is a command line

 ./feelpp_mesh_partitioner --json cases/three-spheres-part.json --ifile cases/three-spheres.geo  --part 24

and to export to paraview

mpirun -np 24 ./feelpp_mesh_exporter --gmsh.filename three-spheres_p24.json

[prudhomm]

@romainhild the testcase is in feelpp/tools/mesh/cases

[github-actions[bot]]

Stale issue message

[Trophime]

@prudhomm would it be possible to export process ids in feelpp_mesh_exporter to view partition within paraview?

[Trophime]

@prudhomm what is the meaning of the "size" parameter in the json defining the partioner aggregation?

[thomas-saigre]

@prudhomm would it be possible to export process ids in feelpp_mesh_exporter to view partition within paraview?

@Trophime I did this modification in https://github.com/feelpp/feelpp/commit/2f01fb2f86c9b0c9ecfd6870f3f01bfe903bea0d (#2222) : the pid is exported when the application feelpp_mesh_exporter is used

[Trophime]

@thomas-saigre Cool. Do you have an example? I need to add an "export_pid" right?

[thomas-saigre]

mpirun -np 4 feelpp_mesh_exporter --gmsh.filename <path/to/your/mesh> --dim <dim> should work. But this is not merged yet, so you will need to recompile from the branch. By default it exports the pid, you can add the option --export_pid 0 to not export them ;)