1 static char help[] = "Tests MatMeshToCellGraph()\n\n"; 2 3 /* 4 Include "petscmat.h" so that we can use matrices. 5 automatically includes: 6 petscsys.h - base PETSc routines petscvec.h - vectors 7 petscmat.h - matrices 8 petscis.h - index sets petscviewer.h - viewers 9 */ 10 #include <petscmat.h> 11 12 int main(int argc, char **args) 13 { 14 Mat mesh, dual; 15 PetscInt Nvertices = 6; /* total number of vertices */ 16 PetscInt ncells = 2; /* number cells on this process */ 17 PetscInt *ii, *jj; 18 PetscMPIInt size, rank; 19 MatPartitioning part; 20 IS is; 21 22 PetscFunctionBeginUser; 23 PetscCall(PetscInitialize(&argc, &args, NULL, help)); 24 PetscCallMPI(MPI_Comm_size(MPI_COMM_WORLD, &size)); 25 PetscCheck(size == 2, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "This example is for exactly two processes"); 26 PetscCallMPI(MPI_Comm_rank(MPI_COMM_WORLD, &rank)); 27 28 PetscCall(PetscMalloc1(3, &ii)); 29 PetscCall(PetscMalloc1(6, &jj)); 30 ii[0] = 0; 31 ii[1] = 3; 32 ii[2] = 6; 33 if (rank == 0) { 34 jj[0] = 0; 35 jj[1] = 1; 36 jj[2] = 2; 37 jj[3] = 1; 38 jj[4] = 2; 39 jj[5] = 3; 40 } else { 41 jj[0] = 1; 42 jj[1] = 4; 43 jj[2] = 5; 44 jj[3] = 1; 45 jj[4] = 3; 46 jj[5] = 5; 47 } 48 PetscCall(MatCreateMPIAdj(MPI_COMM_WORLD, ncells, Nvertices, ii, jj, NULL, &mesh)); 49 PetscCall(MatMeshToCellGraph(mesh, 2, &dual)); 50 PetscCall(MatView(dual, PETSC_VIEWER_STDOUT_WORLD)); 51 52 PetscCall(MatPartitioningCreate(MPI_COMM_WORLD, &part)); 53 PetscCall(MatPartitioningSetAdjacency(part, dual)); 54 PetscCall(MatPartitioningSetFromOptions(part)); 55 PetscCall(MatPartitioningApply(part, &is)); 56 PetscCall(ISView(is, PETSC_VIEWER_STDOUT_WORLD)); 57 PetscCall(ISDestroy(&is)); 58 PetscCall(MatPartitioningDestroy(&part)); 59 60 PetscCall(MatDestroy(&mesh)); 61 PetscCall(MatDestroy(&dual)); 62 PetscCall(PetscFinalize()); 63 return 0; 64 } 65 66 /*TEST 67 68 build: 69 requires: parmetis 70 71 test: 72 nsize: 2 73 74 TEST*/ 75