1c4762a1bSJed Brown 2c4762a1bSJed Brown static char help[] = "Partition tiny grid.\n\n"; 3c4762a1bSJed Brown 4c4762a1bSJed Brown /*T 5c4762a1bSJed Brown Concepts: partitioning 6c4762a1bSJed Brown Processors: 4 7c4762a1bSJed Brown T*/ 8c4762a1bSJed Brown 9c4762a1bSJed Brown /* 10c4762a1bSJed Brown Include "petscmat.h" so that we can use matrices. Note that this file 11c4762a1bSJed Brown automatically includes: 12c4762a1bSJed Brown petscsys.h - base PETSc routines petscvec.h - vectors 13c4762a1bSJed Brown petscmat.h - matrices 14c4762a1bSJed Brown petscis.h - index sets 15c4762a1bSJed Brown petscviewer.h - viewers 16c4762a1bSJed Brown */ 17c4762a1bSJed Brown #include <petscmat.h> 18c4762a1bSJed Brown 19c4762a1bSJed Brown int main(int argc,char **args) 20c4762a1bSJed Brown { 21c4762a1bSJed Brown Mat A; 22c4762a1bSJed Brown PetscErrorCode ierr; 23c4762a1bSJed Brown PetscMPIInt rank,size; 24c4762a1bSJed Brown PetscInt *ia,*ja; 25c4762a1bSJed Brown MatPartitioning part; 26c4762a1bSJed Brown IS is,isn; 27c4762a1bSJed Brown 28c4762a1bSJed Brown ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 29ffc4695bSBarry Smith ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRMPI(ierr); 30*2c71b3e2SJacob Faibussowitsch PetscCheckFalse(size != 4,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Must run with 4 processors"); 31ffc4695bSBarry Smith ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRMPI(ierr); 32c4762a1bSJed Brown 33c4762a1bSJed Brown ierr = PetscMalloc1(5,&ia);CHKERRQ(ierr); 34c4762a1bSJed Brown ierr = PetscMalloc1(16,&ja);CHKERRQ(ierr); 35dd400576SPatrick Sanan if (rank == 0) { 36c4762a1bSJed 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; 37c4762a1bSJed Brown ja[8] = 2; ja[9] = 7; 38c4762a1bSJed Brown ia[0] = 0; ia[1] = 2; ia[2] = 5; ia[3] = 8; ia[4] = 10; 39c4762a1bSJed Brown } else if (rank == 1) { 40c4762a1bSJed 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; 41c4762a1bSJed Brown ja[8] = 5; ja[9] = 7; ja[10] = 10; ja[11] = 3; ja[12] = 6; ja[13] = 11; 42c4762a1bSJed Brown ia[0] = 0; ia[1] = 3; ia[2] = 7; ia[3] = 11; ia[4] = 14; 43c4762a1bSJed Brown } else if (rank == 2) { 44c4762a1bSJed 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; 45c4762a1bSJed Brown ja[8] = 9; ja[9] = 11; ja[10] = 14; ja[11] = 7; ja[12] = 10; ja[13] = 15; 46c4762a1bSJed Brown ia[0] = 0; ia[1] = 3; ia[2] = 7; ia[3] = 11; ia[4] = 14; 47c4762a1bSJed Brown } else { 48c4762a1bSJed 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; 49c4762a1bSJed Brown ja[8] = 11; ja[9] = 14; 50c4762a1bSJed Brown ia[0] = 0; ia[1] = 2; ia[2] = 5; ia[3] = 8; ia[4] = 10; 51c4762a1bSJed Brown } 52c4762a1bSJed Brown 53c4762a1bSJed Brown ierr = MatCreateMPIAdj(PETSC_COMM_WORLD,4,16,ia,ja,NULL,&A);CHKERRQ(ierr); 54c4762a1bSJed Brown ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 55c4762a1bSJed Brown 56c4762a1bSJed Brown /* 57c4762a1bSJed Brown Partition the graph of the matrix 58c4762a1bSJed Brown */ 59c4762a1bSJed Brown ierr = MatPartitioningCreate(PETSC_COMM_WORLD,&part);CHKERRQ(ierr); 60c4762a1bSJed Brown ierr = MatPartitioningSetAdjacency(part,A);CHKERRQ(ierr); 61c4762a1bSJed Brown ierr = MatPartitioningSetFromOptions(part);CHKERRQ(ierr); 62c4762a1bSJed Brown /* get new processor owner number of each vertex */ 63c4762a1bSJed Brown ierr = MatPartitioningApply(part,&is);CHKERRQ(ierr); 64c4762a1bSJed Brown /* get new global number of each old global number */ 65c4762a1bSJed Brown ierr = ISPartitioningToNumbering(is,&isn);CHKERRQ(ierr); 66c4762a1bSJed Brown ierr = ISView(isn,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 67c4762a1bSJed Brown ierr = ISDestroy(&is);CHKERRQ(ierr); 68c4762a1bSJed Brown 69c4762a1bSJed Brown ierr = ISDestroy(&isn);CHKERRQ(ierr); 70c4762a1bSJed Brown ierr = MatPartitioningDestroy(&part);CHKERRQ(ierr); 71c4762a1bSJed Brown 72c4762a1bSJed Brown /* 73c4762a1bSJed Brown Free work space. All PETSc objects should be destroyed when they 74c4762a1bSJed Brown are no longer needed. 75c4762a1bSJed Brown */ 76c4762a1bSJed Brown ierr = MatDestroy(&A);CHKERRQ(ierr); 77c4762a1bSJed Brown 78c4762a1bSJed Brown ierr = PetscFinalize(); 79c4762a1bSJed Brown return ierr; 80c4762a1bSJed Brown } 81c4762a1bSJed Brown 82