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Diffstat (limited to 'HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c')
-rw-r--r-- | HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c new file mode 100644 index 0000000..b397fcf --- /dev/null +++ b/HDF5Examples/C/H5PAR/ph5_hyperslab_by_col.c @@ -0,0 +1,140 @@ +/* + * This example writes data to the HDF5 file by columns. + * Number of processes is assumed to be 2. + */ + +#include "hdf5.h" +#include "stdlib.h" + +#define H5FILE_NAME "SDS_col.h5" +#define DATASETNAME "IntArray" +#define NX 8 /* dataset dimensions */ +#define NY 6 +#define RANK 2 + +int +main(int argc, char **argv) +{ + /* + * HDF5 APIs definitions + */ + hid_t file_id, dset_id; /* file and dataset identifiers */ + hid_t filespace, memspace; /* file and memory dataspace identifiers */ + hsize_t dimsf[2]; /* dataset dimensions */ + hsize_t dimsm[2]; /* dataset dimensions */ + int *data; /* pointer to data buffer to write */ + hsize_t count[2]; /* hyperslab selection parameters */ + hsize_t stride[2]; + hsize_t block[2]; + hsize_t offset[2]; + hid_t plist_id; /* property list identifier */ + int i, j, k; + herr_t status; + + /* + * MPI variables + */ + int mpi_size, mpi_rank; + MPI_Comm comm = MPI_COMM_WORLD; + MPI_Info info = MPI_INFO_NULL; + + /* + * Initialize MPI + */ + MPI_Init(&argc, &argv); + MPI_Comm_size(comm, &mpi_size); + MPI_Comm_rank(comm, &mpi_rank); + /* + * Exit if number of processes is not 2 + */ + if (mpi_size != 2) { + printf("This example to set up to use only 2 processes \n"); + printf("Quitting...\n"); + return 0; + } + + /* + * Set up file access property list with parallel I/O access + */ + plist_id = H5Pcreate(H5P_FILE_ACCESS); + H5Pset_fapl_mpio(plist_id, comm, info); + + /* + * Create a new file collectively and release property list identifier. + */ + file_id = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, plist_id); + H5Pclose(plist_id); + + /* + * Create the dataspace for the dataset. + */ + dimsf[0] = NX; + dimsf[1] = NY; + dimsm[0] = NX; + dimsm[1] = NY / 2; + filespace = H5Screate_simple(RANK, dimsf, NULL); + memspace = H5Screate_simple(RANK, dimsm, NULL); + + /* + * Create the dataset with default properties and close filespace. + */ + dset_id = + H5Dcreate(file_id, DATASETNAME, H5T_NATIVE_INT, filespace, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); + H5Sclose(filespace); + + /* + * Each process defines dataset in memory and writes it to the hyperslab + * in the file. + */ + count[0] = 1; + count[1] = dimsm[1]; + offset[0] = 0; + offset[1] = mpi_rank; + stride[0] = 1; + stride[1] = 2; + block[0] = dimsf[0]; + block[1] = 1; + + /* + * Select hyperslab in the file. + */ + filespace = H5Dget_space(dset_id); + H5Sselect_hyperslab(filespace, H5S_SELECT_SET, offset, stride, count, block); + + /* + * Initialize data buffer + */ + data = (int *)malloc(sizeof(int) * (size_t)dimsm[0] * (size_t)dimsm[1]); + for (i = 0; i < dimsm[0] * dimsm[1]; i = i + dimsm[1]) { + k = 1; + for (j = 0; j < dimsm[1]; j++) { + data[i + j] = (mpi_rank + 1) * k; + k = k * 10; + } + } + + /* + * Create property list for collective dataset write. + */ + plist_id = H5Pcreate(H5P_DATASET_XFER); + H5Pset_dxpl_mpio(plist_id, H5FD_MPIO_COLLECTIVE); + + status = H5Dwrite(dset_id, H5T_NATIVE_INT, memspace, filespace, plist_id, data); + free(data); + + /* + * Close/release resources. + */ + H5Dclose(dset_id); + H5Sclose(filespace); + H5Sclose(memspace); + H5Pclose(plist_id); + H5Fclose(file_id); + + if (mpi_rank == 0) + printf("PHDF5 example finished with no errors\n"); + + MPI_Finalize(); + + return 0; +} |