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 { 44 ia[i] = ia[i-1]; 45 46 /* diagonal */ 47 col = row; 48 { 49 ja[ia[i]] = col; 50 ia[i]++; 51 } 52 53 /* lower diagonal */ 54 col = row-1; 55 if (col >= 0) 56 { 57 ja[ia[i]] = col; 58 ia[i]++; 59 } 60 61 /* upper diagonal */ 62 col = row+1; 63 if (col < N) 64 { 65 ja[ia[i]] = col; 66 ia[i]++; 67 } 68 i++; 69 } 70 71 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 72 PetscCall(MatSetSizes(A, n, n, PETSC_DETERMINE, PETSC_DETERMINE)); 73 PetscCall(MatSetType(A,MATMPIAIJ)); 74 PetscCall(MatMPIAIJSetPreallocationCSR(A, ia, ja, NULL)); 75 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 76 PetscCall(MatDestroy(&A)); 77 78 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 79 PetscCall(MatSetSizes(A, bs*n, bs*n, PETSC_DETERMINE, PETSC_DETERMINE)); 80 PetscCall(MatSetType(A,MATMPIBAIJ)); 81 PetscCall(MatMPIBAIJSetPreallocationCSR(A, bs, ia, ja, NULL)); 82 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 83 PetscCall(MatDestroy(&A)); 84 85 PetscCall(PetscFree(ia)); 86 PetscCall(PetscFree(ja)); 87 PetscCall(PetscFinalize()); 88 return 0; 89 } 90 91 /*TEST 92 93 test: 94 nsize: 4 95 96 TEST*/ 97