1c4762a1bSJed Brown 2c4762a1bSJed Brown static char help[] = "Partition tiny grid.\n\n"; 3c4762a1bSJed Brown 4c4762a1bSJed Brown /* 5c4762a1bSJed Brown Include "petscmat.h" so that we can use matrices. Note that this file 6c4762a1bSJed Brown automatically includes: 7c4762a1bSJed Brown petscsys.h - base PETSc routines petscvec.h - vectors 8c4762a1bSJed Brown petscmat.h - matrices 9c4762a1bSJed Brown petscis.h - index sets 10c4762a1bSJed Brown petscviewer.h - viewers 11c4762a1bSJed Brown */ 12c4762a1bSJed Brown #include <petscmat.h> 13c4762a1bSJed Brown 14c4762a1bSJed Brown int main(int argc,char **args) 15c4762a1bSJed Brown { 166a09307cSBarry Smith Mat A,At; 17c4762a1bSJed Brown PetscMPIInt rank,size; 186a09307cSBarry Smith PetscInt *ia,*ja,row; 19c4762a1bSJed Brown MatPartitioning part; 20c4762a1bSJed Brown IS is,isn; 216a09307cSBarry Smith PetscBool equal; 22c4762a1bSJed Brown 23*327415f7SBarry Smith PetscFunctionBeginUser; 249566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 259566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 26be096a46SBarry Smith PetscCheck(size == 4,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Must run with 4 processors"); 279566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 28c4762a1bSJed Brown 299566063dSJacob Faibussowitsch PetscCall(PetscMalloc1(5,&ia)); 309566063dSJacob Faibussowitsch PetscCall(PetscMalloc1(16,&ja)); 31dd400576SPatrick Sanan if (rank == 0) { 32c4762a1bSJed Brown ja[0] = 1; ja[1] = 4; ja[2] = 0; ja[3] = 2; ja[4] = 5; ja[5] = 1; ja[6] = 3; ja[7] = 6; 33c4762a1bSJed Brown ja[8] = 2; ja[9] = 7; 34c4762a1bSJed Brown ia[0] = 0; ia[1] = 2; ia[2] = 5; ia[3] = 8; ia[4] = 10; 35c4762a1bSJed Brown } else if (rank == 1) { 36c4762a1bSJed Brown ja[0] = 0; ja[1] = 5; ja[2] = 8; ja[3] = 1; ja[4] = 4; ja[5] = 6; ja[6] = 9; ja[7] = 2; 37c4762a1bSJed Brown ja[8] = 5; ja[9] = 7; ja[10] = 10; ja[11] = 3; ja[12] = 6; ja[13] = 11; 38c4762a1bSJed Brown ia[0] = 0; ia[1] = 3; ia[2] = 7; ia[3] = 11; ia[4] = 14; 39c4762a1bSJed Brown } else if (rank == 2) { 40c4762a1bSJed Brown ja[0] = 4; ja[1] = 9; ja[2] = 12; ja[3] = 5; ja[4] = 8; ja[5] = 10; ja[6] = 13; ja[7] = 6; 41c4762a1bSJed Brown ja[8] = 9; ja[9] = 11; ja[10] = 14; ja[11] = 7; ja[12] = 10; ja[13] = 15; 42c4762a1bSJed Brown ia[0] = 0; ia[1] = 3; ia[2] = 7; ia[3] = 11; ia[4] = 14; 43c4762a1bSJed Brown } else { 44c4762a1bSJed Brown ja[0] = 8; ja[1] = 13; ja[2] = 9; ja[3] = 12; ja[4] = 14; ja[5] = 10; ja[6] = 13; ja[7] = 15; 45c4762a1bSJed Brown ja[8] = 11; ja[9] = 14; 46c4762a1bSJed Brown ia[0] = 0; ia[1] = 2; ia[2] = 5; ia[3] = 8; ia[4] = 10; 47c4762a1bSJed Brown } 48c4762a1bSJed Brown 499566063dSJacob Faibussowitsch PetscCall(MatCreateMPIAdj(PETSC_COMM_WORLD,4,16,ia,ja,NULL,&A)); 509566063dSJacob Faibussowitsch PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 51c4762a1bSJed Brown 526a09307cSBarry Smith /* Create the same matrix but using MatSetValues() */ 536a09307cSBarry Smith PetscCall(MatCreate(PETSC_COMM_WORLD,&At)); 546a09307cSBarry Smith PetscCall(MatSetSizes(At,4,4,16,16)); 556a09307cSBarry Smith PetscCall(MatSetType(At,MATMPIADJ)); 566a09307cSBarry Smith for (PetscInt i=0; i<4; i++) { 576a09307cSBarry Smith row = i + 4*rank; 586a09307cSBarry Smith PetscCall(MatSetValues(At,1,&row,ia[i+1]-ia[i],ja + ia[i],NULL,INSERT_VALUES)); 596a09307cSBarry Smith } 606a09307cSBarry Smith PetscCall(MatAssemblyBegin(At,MAT_FINAL_ASSEMBLY)); 616a09307cSBarry Smith PetscCall(MatAssemblyEnd(At,MAT_FINAL_ASSEMBLY)); 626a09307cSBarry Smith PetscCall(MatEqual(A,At,&equal)); 636a09307cSBarry Smith PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Matrices are not equal that should be equal"); 646a09307cSBarry Smith PetscCall(MatDestroy(&At)); 656a09307cSBarry Smith 66c4762a1bSJed Brown /* 67c4762a1bSJed Brown Partition the graph of the matrix 68c4762a1bSJed Brown */ 699566063dSJacob Faibussowitsch PetscCall(MatPartitioningCreate(PETSC_COMM_WORLD,&part)); 709566063dSJacob Faibussowitsch PetscCall(MatPartitioningSetAdjacency(part,A)); 719566063dSJacob Faibussowitsch PetscCall(MatPartitioningSetFromOptions(part)); 72c4762a1bSJed Brown /* get new processor owner number of each vertex */ 739566063dSJacob Faibussowitsch PetscCall(MatPartitioningApply(part,&is)); 74c4762a1bSJed Brown /* get new global number of each old global number */ 759566063dSJacob Faibussowitsch PetscCall(ISPartitioningToNumbering(is,&isn)); 769566063dSJacob Faibussowitsch PetscCall(ISView(isn,PETSC_VIEWER_STDOUT_WORLD)); 779566063dSJacob Faibussowitsch PetscCall(ISDestroy(&is)); 78c4762a1bSJed Brown 799566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isn)); 809566063dSJacob Faibussowitsch PetscCall(MatPartitioningDestroy(&part)); 81c4762a1bSJed Brown 82c4762a1bSJed Brown /* 83c4762a1bSJed Brown Free work space. All PETSc objects should be destroyed when they 84c4762a1bSJed Brown are no longer needed. 85c4762a1bSJed Brown */ 869566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 87c4762a1bSJed Brown 889566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 89b122ec5aSJacob Faibussowitsch return 0; 90c4762a1bSJed Brown } 916a09307cSBarry Smith /* 926a09307cSBarry Smith test: 936a09307cSBarry Smith requires: parmetis 946a09307cSBarry Smith args: -mat_view 956a09307cSBarry Smith nsize: 4 966a09307cSBarry Smith */ 97