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