1c4762a1bSJed Brown static char help[] = "Example of using graph partitioning to partition a graph\n\n"; 2c4762a1bSJed Brown 3c4762a1bSJed Brown #include <petscmat.h> 4c4762a1bSJed Brown 5*9371c9d4SSatish Balay int main(int argc, char **args) { 6c4762a1bSJed Brown Mat A; 7c4762a1bSJed Brown MatPartitioning part; 8c4762a1bSJed Brown IS is; 9c4762a1bSJed Brown PetscInt r, N = 10, start, end, *vweights; 10c4762a1bSJed Brown PetscBool set_vweights = PETSC_FALSE, use_edge_weights = PETSC_FALSE; 11c4762a1bSJed Brown PetscMPIInt rank; 12c4762a1bSJed Brown MPI_Comm comm; 13c4762a1bSJed Brown 14327415f7SBarry Smith PetscFunctionBeginUser; 159566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 16c4762a1bSJed Brown comm = PETSC_COMM_WORLD; 179566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL)); 189566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_rank(comm, &rank)); 199566063dSJacob Faibussowitsch PetscCall(MatCreate(comm, &A)); 209566063dSJacob Faibussowitsch PetscCall(MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, N, N)); 219566063dSJacob Faibussowitsch PetscCall(MatSetFromOptions(A)); 229566063dSJacob Faibussowitsch PetscCall(MatSeqAIJSetPreallocation(A, 3, NULL)); 239566063dSJacob Faibussowitsch PetscCall(MatMPIAIJSetPreallocation(A, 3, NULL, 2, NULL)); 249566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetBool(NULL, NULL, "-test_vertex_weights", &set_vweights, NULL)); 259566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetBool(NULL, NULL, "-test_use_edge_weights", &use_edge_weights, NULL)); 26c4762a1bSJed Brown /* Create a linear mesh */ 279566063dSJacob Faibussowitsch PetscCall(MatGetOwnershipRange(A, &start, &end)); 28c4762a1bSJed Brown if (set_vweights) { 299566063dSJacob Faibussowitsch PetscCall(PetscMalloc1(end - start, &vweights)); 30*9371c9d4SSatish Balay for (r = start; r < end; ++r) vweights[r - start] = rank + 1; 31c4762a1bSJed Brown } 32c4762a1bSJed Brown for (r = start; r < end; ++r) { 33c4762a1bSJed Brown if (r == 0) { 34c4762a1bSJed Brown PetscInt cols[2]; 35c4762a1bSJed Brown PetscScalar vals[2]; 36c4762a1bSJed Brown 37*9371c9d4SSatish Balay cols[0] = r; 38*9371c9d4SSatish Balay cols[1] = r + 1; 39*9371c9d4SSatish Balay vals[0] = 1.0; 40*9371c9d4SSatish Balay vals[1] = use_edge_weights ? 2.0 : 1.0; 41c4762a1bSJed Brown 429566063dSJacob Faibussowitsch PetscCall(MatSetValues(A, 1, &r, 2, cols, vals, INSERT_VALUES)); 43c4762a1bSJed Brown } else if (r == N - 1) { 44c4762a1bSJed Brown PetscInt cols[2]; 45c4762a1bSJed Brown PetscScalar vals[2]; 46c4762a1bSJed Brown 47*9371c9d4SSatish Balay cols[0] = r - 1; 48*9371c9d4SSatish Balay cols[1] = r; 49*9371c9d4SSatish Balay vals[0] = use_edge_weights ? 3.0 : 1.0; 50*9371c9d4SSatish Balay vals[1] = 1.0; 51c4762a1bSJed Brown 529566063dSJacob Faibussowitsch PetscCall(MatSetValues(A, 1, &r, 2, cols, vals, INSERT_VALUES)); 53c4762a1bSJed Brown } else { 54c4762a1bSJed Brown PetscInt cols[3]; 55c4762a1bSJed Brown PetscScalar vals[3]; 56c4762a1bSJed Brown 57*9371c9d4SSatish Balay cols[0] = r - 1; 58*9371c9d4SSatish Balay cols[1] = r; 59*9371c9d4SSatish Balay cols[2] = r + 1; 60c4762a1bSJed Brown /* ADJ matrix needs to be symmetric */ 61c4762a1bSJed Brown vals[0] = use_edge_weights ? (cols[0] == 0 ? 2.0 : 5.0) : 1.0; 62c4762a1bSJed Brown vals[1] = 1.0; 63c4762a1bSJed Brown vals[2] = use_edge_weights ? (cols[2] == N - 1 ? 3.0 : 5.0) : 1.0; 64c4762a1bSJed Brown 659566063dSJacob Faibussowitsch PetscCall(MatSetValues(A, 1, &r, 3, cols, vals, INSERT_VALUES)); 66c4762a1bSJed Brown } 67c4762a1bSJed Brown } 689566063dSJacob Faibussowitsch PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY)); 699566063dSJacob Faibussowitsch PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY)); 70c4762a1bSJed Brown 719566063dSJacob Faibussowitsch PetscCall(MatPartitioningCreate(comm, &part)); 729566063dSJacob Faibussowitsch PetscCall(MatPartitioningSetAdjacency(part, A)); 731baa6e33SBarry Smith if (set_vweights) PetscCall(MatPartitioningSetVertexWeights(part, vweights)); 74c4762a1bSJed Brown if (use_edge_weights) { 759566063dSJacob Faibussowitsch PetscCall(MatPartitioningSetUseEdgeWeights(part, use_edge_weights)); 76c4762a1bSJed Brown 779566063dSJacob Faibussowitsch PetscCall(MatPartitioningGetUseEdgeWeights(part, &use_edge_weights)); 7828b400f6SJacob Faibussowitsch PetscCheck(use_edge_weights, comm, PETSC_ERR_ARG_INCOMP, "use_edge_weights flag does not setup correctly "); 79c4762a1bSJed Brown } 809566063dSJacob Faibussowitsch PetscCall(MatPartitioningSetFromOptions(part)); 819566063dSJacob Faibussowitsch PetscCall(MatPartitioningApply(part, &is)); 829566063dSJacob Faibussowitsch PetscCall(ISView(is, PETSC_VIEWER_STDOUT_WORLD)); 839566063dSJacob Faibussowitsch PetscCall(ISDestroy(&is)); 849566063dSJacob Faibussowitsch PetscCall(MatPartitioningDestroy(&part)); 85c4762a1bSJed Brown 869566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 879566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 88b122ec5aSJacob Faibussowitsch return 0; 89c4762a1bSJed Brown } 90c4762a1bSJed Brown 91c4762a1bSJed Brown /*TEST 92c4762a1bSJed Brown 93c4762a1bSJed Brown test: 94c4762a1bSJed Brown nsize: 3 95c4762a1bSJed Brown requires: parmetis 96c4762a1bSJed Brown args: -mat_partitioning_type parmetis 97c4762a1bSJed Brown 98c4762a1bSJed Brown test: 99c4762a1bSJed Brown suffix: 2 100c4762a1bSJed Brown nsize: 3 101c4762a1bSJed Brown requires: ptscotch 102c4762a1bSJed Brown args: -mat_partitioning_type ptscotch 103c4762a1bSJed Brown 104c4762a1bSJed Brown test: 105c4762a1bSJed Brown suffix: 3 106c4762a1bSJed Brown nsize: 4 107c4762a1bSJed Brown requires: party 108c4762a1bSJed Brown args: -mat_partitioning_type party 109c4762a1bSJed Brown 110c4762a1bSJed Brown test: 111c4762a1bSJed Brown suffix: 4 112c4762a1bSJed Brown nsize: 3 113c4762a1bSJed Brown requires: chaco 114c4762a1bSJed Brown args: -mat_partitioning_type chaco 115c4762a1bSJed Brown 116c4762a1bSJed Brown test: 117c4762a1bSJed Brown suffix: 5 118c4762a1bSJed Brown nsize: 3 119c4762a1bSJed Brown requires: parmetis 120c4762a1bSJed Brown args: -mat_partitioning_type hierarch -mat_partitioning_hierarchical_nfineparts 3 -mat_partitioning_nparts 10 -N 100 121c4762a1bSJed Brown 122c4762a1bSJed Brown test: 123c4762a1bSJed Brown suffix: 6 124c4762a1bSJed Brown nsize: 3 125c4762a1bSJed Brown requires: parmetis 126c4762a1bSJed Brown args: -mat_partitioning_type hierarch -mat_partitioning_hierarchical_nfineparts 3 -mat_partitioning_nparts 10 -N 100 -test_vertex_weights 1 -mat_partitioning_use_edge_weights 1 127c4762a1bSJed Brown 128c4762a1bSJed Brown test: 129c4762a1bSJed Brown suffix: 7 130c4762a1bSJed Brown nsize: 2 131c4762a1bSJed Brown requires: parmetis 132c4762a1bSJed Brown args: -mat_partitioning_type hierarch -mat_partitioning_hierarchical_nfineparts 2 -mat_partitioning_nparts 10 -mat_partitioning_hierarchical_fineparttype hierarch -malloc_dump -N 100 -mat_partitioning_improve 1 133c4762a1bSJed Brown 134c4762a1bSJed Brown test: 135c4762a1bSJed Brown suffix: 8 136c4762a1bSJed Brown nsize: 2 137c4762a1bSJed Brown requires: parmetis 138c4762a1bSJed Brown args: -mat_partitioning_type parmetis -mat_partitioning_nparts 3 -test_use_edge_weights 1 139c4762a1bSJed Brown 140c4762a1bSJed Brown test: 141c4762a1bSJed Brown suffix: 9 142c4762a1bSJed Brown nsize: 2 143c4762a1bSJed Brown requires: ptscotch 144c4762a1bSJed Brown args: -mat_partitioning_type ptscotch -mat_partitioning_nparts 3 -test_use_edge_weights 1 -mat_partitioning_ptscotch_proc_weight 0 145c4762a1bSJed Brown 146c4762a1bSJed Brown TEST*/ 147