Actual source code: ex11.c


  2: static char help[] = "Tests MatMeshToDual()\n\n";

  4: /*
  5:   Include "petscmat.h" so that we can use matrices.
  6:   automatically includes:
  7:      petscsys.h       - base PETSc routines   petscvec.h    - vectors
  8:      petscmat.h    - matrices
  9:      petscis.h     - index sets            petscviewer.h - viewers
 10: */
 11: #include <petscmat.h>

 13: int main(int argc, char **args)
 14: {
 15:   Mat             mesh, dual;
 16:   PetscInt        Nvertices = 6; /* total number of vertices */
 17:   PetscInt        ncells    = 2; /* number cells on this process */
 18:   PetscInt       *ii, *jj;
 19:   PetscMPIInt     size, rank;
 20:   MatPartitioning part;
 21:   IS              is;

 23:   PetscFunctionBeginUser;
 24:   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
 25:   PetscCallMPI(MPI_Comm_size(MPI_COMM_WORLD, &size));
 26:   PetscCheck(size == 2, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "This example is for exactly two processes");
 27:   PetscCallMPI(MPI_Comm_rank(MPI_COMM_WORLD, &rank));

 29:   PetscCall(PetscMalloc1(3, &ii));
 30:   PetscCall(PetscMalloc1(6, &jj));
 31:   ii[0] = 0;
 32:   ii[1] = 3;
 33:   ii[2] = 6;
 34:   if (rank == 0) {
 35:     jj[0] = 0;
 36:     jj[1] = 1;
 37:     jj[2] = 2;
 38:     jj[3] = 1;
 39:     jj[4] = 2;
 40:     jj[5] = 3;
 41:   } else {
 42:     jj[0] = 1;
 43:     jj[1] = 4;
 44:     jj[2] = 5;
 45:     jj[3] = 1;
 46:     jj[4] = 3;
 47:     jj[5] = 5;
 48:   }
 49:   PetscCall(MatCreateMPIAdj(MPI_COMM_WORLD, ncells, Nvertices, ii, jj, NULL, &mesh));
 50:   PetscCall(MatMeshToCellGraph(mesh, 2, &dual));
 51:   PetscCall(MatView(dual, PETSC_VIEWER_STDOUT_WORLD));

 53:   PetscCall(MatPartitioningCreate(MPI_COMM_WORLD, &part));
 54:   PetscCall(MatPartitioningSetAdjacency(part, dual));
 55:   PetscCall(MatPartitioningSetFromOptions(part));
 56:   PetscCall(MatPartitioningApply(part, &is));
 57:   PetscCall(ISView(is, PETSC_VIEWER_STDOUT_WORLD));
 58:   PetscCall(ISDestroy(&is));
 59:   PetscCall(MatPartitioningDestroy(&part));

 61:   PetscCall(MatDestroy(&mesh));
 62:   PetscCall(MatDestroy(&dual));
 63:   PetscCall(PetscFinalize());
 64:   return 0;
 65: }

 67: /*TEST

 69:    build:
 70:      requires: parmetis

 72:    test:
 73:       nsize: 2
 74:       requires: parmetis

 76: TEST*/