1c4762a1bSJed Brown static char help[] = "Example of using graph partitioning with a matrix in which some procs have empty ownership\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 i, m, N, rstart, rend, nemptyranks, *emptyranks, nbigranks, *bigranks; 10c4762a1bSJed Brown PetscMPIInt rank, size; 11c4762a1bSJed Brown 12327415f7SBarry Smith PetscFunctionBeginUser; 139566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 149566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 159566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 16c4762a1bSJed Brown 17c4762a1bSJed Brown nemptyranks = 10; 18c4762a1bSJed Brown nbigranks = 10; 199566063dSJacob Faibussowitsch PetscCall(PetscMalloc2(nemptyranks, &emptyranks, nbigranks, &bigranks)); 20c4762a1bSJed Brown 21d0609cedSBarry Smith PetscOptionsBegin(PETSC_COMM_WORLD, NULL, "Partitioning example options", NULL); 229566063dSJacob Faibussowitsch PetscCall(PetscOptionsIntArray("-emptyranks", "Ranks to be skipped by partition", "", emptyranks, &nemptyranks, NULL)); 239566063dSJacob Faibussowitsch PetscCall(PetscOptionsIntArray("-bigranks", "Ranks to be overloaded", "", bigranks, &nbigranks, NULL)); 24d0609cedSBarry Smith PetscOptionsEnd(); 25c4762a1bSJed Brown 26c4762a1bSJed Brown m = 1; 27*9371c9d4SSatish Balay for (i = 0; i < nemptyranks; i++) 28*9371c9d4SSatish Balay if (rank == emptyranks[i]) m = 0; 29*9371c9d4SSatish Balay for (i = 0; i < nbigranks; i++) 30*9371c9d4SSatish Balay if (rank == bigranks[i]) m = 5; 31c4762a1bSJed Brown 329566063dSJacob Faibussowitsch PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 339566063dSJacob Faibussowitsch PetscCall(MatSetSizes(A, m, m, PETSC_DECIDE, PETSC_DECIDE)); 349566063dSJacob Faibussowitsch PetscCall(MatSetFromOptions(A)); 359566063dSJacob Faibussowitsch PetscCall(MatSeqAIJSetPreallocation(A, 3, NULL)); 369566063dSJacob Faibussowitsch PetscCall(MatMPIAIJSetPreallocation(A, 3, NULL, 2, NULL)); 379566063dSJacob Faibussowitsch PetscCall(MatSeqBAIJSetPreallocation(A, 1, 3, NULL)); 389566063dSJacob Faibussowitsch PetscCall(MatMPIBAIJSetPreallocation(A, 1, 3, NULL, 2, NULL)); 399566063dSJacob Faibussowitsch PetscCall(MatSeqSBAIJSetPreallocation(A, 1, 2, NULL)); 409566063dSJacob Faibussowitsch PetscCall(MatMPISBAIJSetPreallocation(A, 1, 2, NULL, 1, NULL)); 41c4762a1bSJed Brown 429566063dSJacob Faibussowitsch PetscCall(MatGetSize(A, NULL, &N)); 439566063dSJacob Faibussowitsch PetscCall(MatGetOwnershipRange(A, &rstart, &rend)); 44c4762a1bSJed Brown for (i = rstart; i < rend; i++) { 45c4762a1bSJed Brown const PetscInt cols[] = {(i + N - 1) % N, i, (i + 1) % N}; 46c4762a1bSJed Brown const PetscScalar vals[] = {1, 1, 1}; 479566063dSJacob Faibussowitsch PetscCall(MatSetValues(A, 1, &i, 3, cols, vals, INSERT_VALUES)); 48c4762a1bSJed Brown } 499566063dSJacob Faibussowitsch PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY)); 509566063dSJacob Faibussowitsch PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY)); 519566063dSJacob Faibussowitsch PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD)); 52c4762a1bSJed Brown 539566063dSJacob Faibussowitsch PetscCall(MatPartitioningCreate(PETSC_COMM_WORLD, &part)); 549566063dSJacob Faibussowitsch PetscCall(MatPartitioningSetAdjacency(part, A)); 559566063dSJacob Faibussowitsch PetscCall(MatPartitioningSetFromOptions(part)); 569566063dSJacob Faibussowitsch PetscCall(MatPartitioningApply(part, &is)); 579566063dSJacob Faibussowitsch PetscCall(ISView(is, PETSC_VIEWER_STDOUT_WORLD)); 589566063dSJacob Faibussowitsch PetscCall(ISDestroy(&is)); 599566063dSJacob Faibussowitsch PetscCall(MatPartitioningDestroy(&part)); 609566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 619566063dSJacob Faibussowitsch PetscCall(PetscFree2(emptyranks, bigranks)); 629566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 63b122ec5aSJacob Faibussowitsch return 0; 64c4762a1bSJed Brown } 65c4762a1bSJed Brown 66c4762a1bSJed Brown /*TEST 67c4762a1bSJed Brown 68c4762a1bSJed Brown test: 69c4762a1bSJed Brown nsize: 8 70c4762a1bSJed Brown args: -emptyranks 0,2,4 -bigranks 1,3,7 -mat_partitioning_type average 71c4762a1bSJed Brown # cannot test with external package partitioners since they produce different results on different systems 72c4762a1bSJed Brown 73c4762a1bSJed Brown TEST*/ 74