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 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 25 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 26 PetscCheck(size < 5,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Can only use at most 4 processors."); 27 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 28 29 /* Get a partition range based on the vector size */ 30 PetscCall(VecCreateMPI(PETSC_COMM_WORLD, PETSC_DECIDE, N, &v)); 31 PetscCall(VecGetLocalSize(v, &n)); 32 PetscCall(VecGetOwnershipRange(v, &rstart, &rend)); 33 PetscCall(VecDestroy(&v)); 34 35 PetscCall(PetscMalloc1(n+1,&ia)); 36 PetscCall(PetscMalloc1(3*n,&ja)); 37 38 /* Construct a tri-diagonal CSR indexing */ 39 i = 1; 40 ia[0] = 0; 41 for (row = rstart; row < rend; row++) 42 { 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 { 56 ja[ia[i]] = col; 57 ia[i]++; 58 } 59 60 /* upper diagonal */ 61 col = row+1; 62 if (col < N) 63 { 64 ja[ia[i]] = col; 65 ia[i]++; 66 } 67 i++; 68 } 69 70 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 71 PetscCall(MatSetSizes(A, n, n, PETSC_DETERMINE, PETSC_DETERMINE)); 72 PetscCall(MatSetType(A,MATMPIAIJ)); 73 PetscCall(MatMPIAIJSetPreallocationCSR(A, ia, ja, NULL)); 74 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 75 PetscCall(MatDestroy(&A)); 76 77 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 78 PetscCall(MatSetSizes(A, bs*n, bs*n, PETSC_DETERMINE, PETSC_DETERMINE)); 79 PetscCall(MatSetType(A,MATMPIBAIJ)); 80 PetscCall(MatMPIBAIJSetPreallocationCSR(A, bs, ia, ja, NULL)); 81 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 82 PetscCall(MatDestroy(&A)); 83 84 PetscCall(PetscFree(ia)); 85 PetscCall(PetscFree(ja)); 86 PetscCall(PetscFinalize()); 87 return 0; 88 } 89 90 /*TEST 91 92 test: 93 nsize: 4 94 95 TEST*/ 96