1 2 static char help[] = "Tests binary I/O of vectors and illustrates the use of user-defined event logging.\n\n"; 3 4 #include <petscvec.h> 5 6 /* Note: Most applications would not read and write a vector 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 PetscMPIInt rank, size; 13 PetscInt i, m = 10, low, high, ldim, iglobal; 14 PetscScalar v; 15 Vec u; 16 PetscViewer viewer; 17 PetscLogEvent VECTOR_GENERATE, VECTOR_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 25 /* PART 1: Generate vector, then write it in binary format */ 26 27 PetscCall(PetscLogEventRegister("Generate Vector", VEC_CLASSID, &VECTOR_GENERATE)); 28 PetscCall(PetscLogEventBegin(VECTOR_GENERATE, 0, 0, 0, 0)); 29 /* Generate vector */ 30 PetscCall(VecCreate(PETSC_COMM_WORLD, &u)); 31 PetscCall(VecSetSizes(u, PETSC_DECIDE, m)); 32 PetscCall(VecSetFromOptions(u)); 33 PetscCall(VecGetOwnershipRange(u, &low, &high)); 34 PetscCall(VecGetLocalSize(u, &ldim)); 35 for (i = 0; i < ldim; i++) { 36 iglobal = i + low; 37 v = (PetscScalar)(i + 100 * rank); 38 PetscCall(VecSetValues(u, 1, &iglobal, &v, INSERT_VALUES)); 39 } 40 PetscCall(VecAssemblyBegin(u)); 41 PetscCall(VecAssemblyEnd(u)); 42 PetscCall(VecView(u, PETSC_VIEWER_STDOUT_WORLD)); 43 44 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "writing vector in binary to vector.dat ...\n")); 45 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "vector.dat", FILE_MODE_WRITE, &viewer)); 46 PetscCall(VecView(u, viewer)); 47 PetscCall(PetscViewerDestroy(&viewer)); 48 PetscCall(VecDestroy(&u)); 49 PetscCall(PetscOptionsSetValue(NULL, "-viewer_binary_mpiio", "")); 50 51 PetscCall(PetscLogEventEnd(VECTOR_GENERATE, 0, 0, 0, 0)); 52 53 /* PART 2: Read in vector in binary format */ 54 55 /* Read new vector in binary format */ 56 PetscCall(PetscLogEventRegister("Read Vector", VEC_CLASSID, &VECTOR_READ)); 57 PetscCall(PetscLogEventBegin(VECTOR_READ, 0, 0, 0, 0)); 58 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "reading vector in binary from vector.dat ...\n")); 59 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "vector.dat", FILE_MODE_READ, &viewer)); 60 PetscCall(VecCreate(PETSC_COMM_WORLD, &u)); 61 PetscCall(VecLoad(u, viewer)); 62 PetscCall(PetscViewerDestroy(&viewer)); 63 PetscCall(PetscLogEventEnd(VECTOR_READ, 0, 0, 0, 0)); 64 PetscCall(VecView(u, PETSC_VIEWER_STDOUT_WORLD)); 65 66 /* Free data structures */ 67 PetscCall(VecDestroy(&u)); 68 PetscCall(PetscFinalize()); 69 return 0; 70 } 71 72 /*TEST 73 74 test: 75 nsize: 1 76 requires: mpiio 77 78 test: 79 suffix: 2 80 nsize: 2 81 requires: mpiio 82 83 TEST*/ 84