1 2 static char help[] = "Reads a PETSc matrix and vector from a file; expands the matrix with the vector\n\n"; 3 4 /* 5 Include "petscmat.h" so that we can use matrices. 6 automatically includes: 7 petscsys.h - base PETSc routines petscvec.h - vectors 8 petscmat.h - matrices 9 petscis.h - index sets petscviewer.h - viewers 10 */ 11 #include <petscmat.h> 12 13 /* 14 15 Adds a new column and row to the vector (the last) containing the vector 16 */ 17 PetscErrorCode PadMatrix(Mat A, Vec v, PetscScalar c, Mat *B) 18 { 19 PetscInt n, i, *cnt, *indices, nc; 20 const PetscInt *aj; 21 const PetscScalar *vv, *aa; 22 23 PetscFunctionBegin; 24 PetscCall(MatGetSize(A, &n, NULL)); 25 PetscCall(VecGetArrayRead(v, &vv)); 26 PetscCall(PetscMalloc1(n, &indices)); 27 for (i = 0; i < n; i++) indices[i] = i; 28 29 /* determine number of nonzeros per row in the new matrix */ 30 PetscCall(PetscMalloc1(n + 1, &cnt)); 31 for (i = 0; i < n; i++) { 32 PetscCall(MatGetRow(A, i, &nc, NULL, NULL)); 33 cnt[i] = nc + (vv[i] != 0.0); 34 PetscCall(MatRestoreRow(A, i, &nc, NULL, NULL)); 35 } 36 cnt[n] = 1; 37 for (i = 0; i < n; i++) cnt[n] += (vv[i] != 0.0); 38 PetscCall(MatCreateSeqAIJ(PETSC_COMM_SELF, n + 1, n + 1, 0, cnt, B)); 39 PetscCall(MatSetOption(*B, MAT_IGNORE_ZERO_ENTRIES, PETSC_TRUE)); 40 41 /* copy over the matrix entries from the matrix and then the vector */ 42 for (i = 0; i < n; i++) { 43 PetscCall(MatGetRow(A, i, &nc, &aj, &aa)); 44 PetscCall(MatSetValues(*B, 1, &i, nc, aj, aa, INSERT_VALUES)); 45 PetscCall(MatRestoreRow(A, i, &nc, &aj, &aa)); 46 } 47 PetscCall(MatSetValues(*B, 1, &n, n, indices, vv, INSERT_VALUES)); 48 PetscCall(MatSetValues(*B, n, indices, 1, &n, vv, INSERT_VALUES)); 49 PetscCall(MatSetValues(*B, 1, &n, 1, &n, &c, INSERT_VALUES)); 50 51 PetscCall(MatAssemblyBegin(*B, MAT_FINAL_ASSEMBLY)); 52 PetscCall(MatAssemblyEnd(*B, MAT_FINAL_ASSEMBLY)); 53 PetscCall(VecRestoreArrayRead(v, &vv)); 54 PetscCall(PetscFree(cnt)); 55 PetscCall(PetscFree(indices)); 56 PetscFunctionReturn(0); 57 } 58 59 int main(int argc, char **args) 60 { 61 Mat A, B; 62 PetscViewer fd; /* viewer */ 63 char file[PETSC_MAX_PATH_LEN]; /* input file name */ 64 PetscBool flg; 65 Vec v; 66 67 PetscFunctionBeginUser; 68 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 69 /* 70 Determine files from which we read the two linear systems 71 (matrix and right-hand-side vector). 72 */ 73 PetscCall(PetscOptionsGetString(NULL, NULL, "-f0", file, sizeof(file), &flg)); 74 PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -f0 option"); 75 76 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd)); 77 78 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 79 PetscCall(MatSetType(A, MATSEQAIJ)); 80 PetscCall(MatLoad(A, fd)); 81 PetscCall(VecCreate(PETSC_COMM_WORLD, &v)); 82 PetscCall(VecLoad(v, fd)); 83 PetscCall(MatView(A, PETSC_VIEWER_STDOUT_SELF)); 84 PetscCall(PadMatrix(A, v, 3.0, &B)); 85 PetscCall(MatView(B, PETSC_VIEWER_STDOUT_SELF)); 86 PetscCall(MatDestroy(&B)); 87 PetscCall(MatDestroy(&A)); 88 PetscCall(VecDestroy(&v)); 89 PetscCall(PetscViewerDestroy(&fd)); 90 91 PetscCall(PetscFinalize()); 92 return 0; 93 } 94 95 /*TEST 96 97 test: 98 args: -f0 ${wPETSC_DIR}/share/petsc/datafiles/matrices/ns-real-int32-float64 99 requires: double !complex !defined(PETSC_USE_64BIT_INDICES) 100 101 TEST*/ 102