1 static char help[] = "Tests binary I/O of vectors and illustrates the use of user-defined event logging.\n\n"; 2 3 #include <petscvec.h> 4 5 /* Note: Most applications would not read and write a vector within 6 the same program. This example is intended only to demonstrate 7 both input and output. */ 8 9 int main(int argc, char **args) 10 { 11 PetscMPIInt rank, size; 12 PetscInt i, m = 10, low, high, ldim, iglobal; 13 PetscScalar v; 14 Vec u; 15 PetscViewer viewer; 16 PetscLogEvent VECTOR_GENERATE, VECTOR_READ; 17 18 PetscFunctionBeginUser; 19 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 20 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 21 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 22 PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL)); 23 24 /* PART 1: Generate vector, then write it in binary format */ 25 26 PetscCall(PetscLogEventRegister("Generate Vector", VEC_CLASSID, &VECTOR_GENERATE)); 27 PetscCall(PetscLogEventBegin(VECTOR_GENERATE, 0, 0, 0, 0)); 28 /* Generate vector */ 29 PetscCall(VecCreate(PETSC_COMM_WORLD, &u)); 30 PetscCall(VecSetSizes(u, PETSC_DECIDE, m)); 31 PetscCall(VecSetFromOptions(u)); 32 PetscCall(VecGetOwnershipRange(u, &low, &high)); 33 PetscCall(VecGetLocalSize(u, &ldim)); 34 for (i = 0; i < ldim; i++) { 35 iglobal = i + low; 36 v = (PetscScalar)(i + 100 * rank); 37 PetscCall(VecSetValues(u, 1, &iglobal, &v, INSERT_VALUES)); 38 } 39 PetscCall(VecAssemblyBegin(u)); 40 PetscCall(VecAssemblyEnd(u)); 41 PetscCall(VecView(u, PETSC_VIEWER_STDOUT_WORLD)); 42 43 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "writing vector in binary to vector.dat ...\n")); 44 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "vector.dat", FILE_MODE_WRITE, &viewer)); 45 PetscCall(VecView(u, viewer)); 46 PetscCall(PetscViewerDestroy(&viewer)); 47 PetscCall(VecDestroy(&u)); 48 PetscCall(PetscOptionsSetValue(NULL, "-viewer_binary_mpiio", "")); 49 50 PetscCall(PetscLogEventEnd(VECTOR_GENERATE, 0, 0, 0, 0)); 51 52 /* PART 2: Read in vector in binary format */ 53 54 /* Read new vector in binary format */ 55 PetscCall(PetscLogEventRegister("Read Vector", VEC_CLASSID, &VECTOR_READ)); 56 PetscCall(PetscLogEventBegin(VECTOR_READ, 0, 0, 0, 0)); 57 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "reading vector in binary from vector.dat ...\n")); 58 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "vector.dat", FILE_MODE_READ, &viewer)); 59 PetscCall(VecCreate(PETSC_COMM_WORLD, &u)); 60 PetscCall(VecLoad(u, viewer)); 61 PetscCall(PetscViewerDestroy(&viewer)); 62 PetscCall(PetscLogEventEnd(VECTOR_READ, 0, 0, 0, 0)); 63 PetscCall(VecView(u, PETSC_VIEWER_STDOUT_WORLD)); 64 65 /* Free data structures */ 66 PetscCall(VecDestroy(&u)); 67 PetscCall(PetscFinalize()); 68 return 0; 69 } 70 71 /*TEST 72 73 test: 74 nsize: 1 75 requires: mpiio 76 77 test: 78 suffix: 2 79 nsize: 2 80 requires: mpiio 81 82 TEST*/ 83