1 2 static char help[] = "Tests binary I/O of matrices and illustrates user-defined event logging.\n\n"; 3 4 #include <petscmat.h> 5 6 /* Note: Most applications would not read and write the same matrix within 7 the same program. This example is intended only to demonstrate 8 both input and output. */ 9 10 int main(int argc, char **args) 11 { 12 Mat C; 13 PetscScalar v; 14 PetscInt i, j, Ii, J, Istart, Iend, N, m = 4, n = 4; 15 PetscMPIInt rank, size; 16 PetscViewer viewer; 17 PetscLogEvent MATRIX_GENERATE, MATRIX_READ; 18 19 PetscFunctionBeginUser; 20 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 21 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 22 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 23 PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL)); 24 PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL)); 25 N = m * n; 26 27 /* PART 1: Generate matrix, then write it in binary format */ 28 29 PetscCall(PetscLogEventRegister("Generate Matrix", 0, &MATRIX_GENERATE)); 30 PetscCall(PetscLogEventBegin(MATRIX_GENERATE, 0, 0, 0, 0)); 31 32 /* Generate matrix */ 33 PetscCall(MatCreate(PETSC_COMM_WORLD, &C)); 34 PetscCall(MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, N, N)); 35 PetscCall(MatSetFromOptions(C)); 36 PetscCall(MatSetUp(C)); 37 PetscCall(MatGetOwnershipRange(C, &Istart, &Iend)); 38 for (Ii = Istart; Ii < Iend; Ii++) { 39 v = -1.0; 40 i = Ii / n; 41 j = Ii - i * n; 42 if (i > 0) { 43 J = Ii - n; 44 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, ADD_VALUES)); 45 } 46 if (i < m - 1) { 47 J = Ii + n; 48 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, ADD_VALUES)); 49 } 50 if (j > 0) { 51 J = Ii - 1; 52 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, ADD_VALUES)); 53 } 54 if (j < n - 1) { 55 J = Ii + 1; 56 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, ADD_VALUES)); 57 } 58 v = 4.0; 59 PetscCall(MatSetValues(C, 1, &Ii, 1, &Ii, &v, ADD_VALUES)); 60 } 61 PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY)); 62 PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY)); 63 PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD)); 64 65 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "writing matrix in binary to matrix.dat ...\n")); 66 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "matrix.dat", FILE_MODE_WRITE, &viewer)); 67 PetscCall(MatView(C, viewer)); 68 PetscCall(PetscViewerDestroy(&viewer)); 69 PetscCall(MatDestroy(&C)); 70 PetscCall(PetscLogEventEnd(MATRIX_GENERATE, 0, 0, 0, 0)); 71 72 /* PART 2: Read in matrix in binary format */ 73 74 /* All processors wait until test matrix has been dumped */ 75 PetscCallMPI(MPI_Barrier(PETSC_COMM_WORLD)); 76 77 PetscCall(PetscLogEventRegister("Read Matrix", 0, &MATRIX_READ)); 78 PetscCall(PetscLogEventBegin(MATRIX_READ, 0, 0, 0, 0)); 79 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "reading matrix in binary from matrix.dat ...\n")); 80 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "matrix.dat", FILE_MODE_READ, &viewer)); 81 PetscCall(MatCreate(PETSC_COMM_WORLD, &C)); 82 PetscCall(MatLoad(C, viewer)); 83 PetscCall(PetscViewerDestroy(&viewer)); 84 PetscCall(PetscLogEventEnd(MATRIX_READ, 0, 0, 0, 0)); 85 PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD)); 86 87 /* Free data structures */ 88 PetscCall(MatDestroy(&C)); 89 90 PetscCall(PetscFinalize()); 91 return 0; 92 } 93 94 /*TEST 95 96 test: 97 filter: grep -v " MPI process" 98 99 TEST*/ 100