1 2 static char help[] = "Tests MatMPIBAIJSetPreallocationCSR()\n\n"; 3 4 /*T 5 Concepts: partitioning 6 Processors: 4 7 T*/ 8 9 /* 10 Include "petscmat.h" so that we can use matrices. Note that this file 11 automatically includes: 12 petscsys.h - base PETSc routines petscvec.h - vectors 13 petscmat.h - matrices 14 petscis.h - index sets 15 petscviewer.h - viewers 16 */ 17 #include <petscmat.h> 18 19 int main(int argc,char **args) 20 { 21 Mat A; 22 PetscInt *ia,*ja, bs = 2; 23 PetscInt N = 9, n; 24 PetscInt rstart, rend, row, col; 25 PetscInt i; 26 PetscMPIInt rank,size; 27 Vec v; 28 29 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 30 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 31 PetscCheckFalse(size > 4,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Can only use at most 4 processors."); 32 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 33 34 /* Get a partition range based on the vector size */ 35 PetscCall(VecCreateMPI(PETSC_COMM_WORLD, PETSC_DECIDE, N, &v)); 36 PetscCall(VecGetLocalSize(v, &n)); 37 PetscCall(VecGetOwnershipRange(v, &rstart, &rend)); 38 PetscCall(VecDestroy(&v)); 39 40 PetscCall(PetscMalloc1(n+1,&ia)); 41 PetscCall(PetscMalloc1(3*n,&ja)); 42 43 /* Construct a tri-diagonal CSR indexing */ 44 i = 1; 45 ia[0] = 0; 46 for (row = rstart; row < rend; row++) 47 { 48 ia[i] = ia[i-1]; 49 50 /* diagonal */ 51 col = row; 52 { 53 ja[ia[i]] = col; 54 ia[i]++; 55 } 56 57 /* lower diagonal */ 58 col = row-1; 59 if (col >= 0) 60 { 61 ja[ia[i]] = col; 62 ia[i]++; 63 } 64 65 /* upper diagonal */ 66 col = row+1; 67 if (col < N) 68 { 69 ja[ia[i]] = col; 70 ia[i]++; 71 } 72 i++; 73 } 74 75 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 76 PetscCall(MatSetSizes(A, n, n, PETSC_DETERMINE, PETSC_DETERMINE)); 77 PetscCall(MatSetType(A,MATMPIAIJ)); 78 PetscCall(MatMPIAIJSetPreallocationCSR(A, ia, ja, NULL)); 79 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 80 PetscCall(MatDestroy(&A)); 81 82 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 83 PetscCall(MatSetSizes(A, bs*n, bs*n, PETSC_DETERMINE, PETSC_DETERMINE)); 84 PetscCall(MatSetType(A,MATMPIBAIJ)); 85 PetscCall(MatMPIBAIJSetPreallocationCSR(A, bs, ia, ja, NULL)); 86 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 87 PetscCall(MatDestroy(&A)); 88 89 PetscCall(PetscFree(ia)); 90 PetscCall(PetscFree(ja)); 91 PetscCall(PetscFinalize()); 92 return 0; 93 } 94 95 /*TEST 96 97 test: 98 nsize: 4 99 100 TEST*/ 101