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