1 2 static char help[] = "Saves a dense matrix in a dense format (binary).\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc, char **args) 7 { 8 Mat C; 9 PetscScalar v; 10 PetscInt i, j, m = 4, n = 4; 11 PetscMPIInt rank, size; 12 PetscViewer viewer; 13 14 PetscFunctionBeginUser; 15 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 16 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 17 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 18 PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL)); 19 PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL)); 20 21 /* PART 1: Generate matrix, then write it in binary format */ 22 23 /* Generate matrix */ 24 PetscCall(MatCreateSeqDense(PETSC_COMM_WORLD, m, n, NULL, &C)); 25 for (i = 0; i < m; i++) { 26 for (j = 0; j < n; j++) { 27 v = i * m + j; 28 PetscCall(MatSetValues(C, 1, &i, 1, &j, &v, INSERT_VALUES)); 29 } 30 } 31 PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY)); 32 PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY)); 33 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "matrix.dat", FILE_MODE_WRITE, &viewer)); 34 PetscCall(MatView(C, viewer)); 35 PetscCall(PetscViewerDestroy(&viewer)); 36 PetscCall(MatDestroy(&C)); 37 PetscCall(PetscFinalize()); 38 return 0; 39 } 40 41 /*TEST 42 43 test: 44 45 TEST*/ 46