hdf5/hl/examples/ex_table_05.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://support.hdfgroup.org/ftp/HDF5/releases.  *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#include "hdf5.h"
#include "hdf5_hl.h"
#include <stdlib.h>

/*-------------------------------------------------------------------------
 * Table API example
 *
 * H5TBwrite_fields_index
 *
 *-------------------------------------------------------------------------
 */

#define NFIELDS      (hsize_t)5
#define NRECORDS     (hsize_t)8
#define NRECORDS_ADD (hsize_t)3
#define TABLE_NAME   "table"

int
main(void)
{
    typedef struct Particle {
        char   name[16];
        int    lati;
        int    longi;
        float  pressure;
        double temperature;
    } Particle;

    /* Define a subset of Particle, with latitude and longitude fields */
    typedef struct Position {
        int lati;
        int longi;
    } Position;

    /* Calculate the type_size and the offsets of our struct members */
    Particle dst_buf[NRECORDS];
    size_t   dst_size          = sizeof(Particle);
    size_t dst_offset[NFIELDS] = {HOFFSET(Particle, name), HOFFSET(Particle, lati), HOFFSET(Particle, longi),
                                  HOFFSET(Particle, pressure), HOFFSET(Particle, temperature)};
    size_t dst_sizes[NFIELDS]  = {sizeof(dst_buf[0].name), sizeof(dst_buf[0].lati), sizeof(dst_buf[0].longi),
                                 sizeof(dst_buf[0].pressure), sizeof(dst_buf[0].temperature)};

    size_t field_offset_pos[2] = {HOFFSET(Position, lati), HOFFSET(Position, longi)};

    /* Initially no data */
    Particle *p_data = NULL;

    /* Define field information */
    const char *field_names[NFIELDS] = {"Name", "Latitude", "Longitude", "Pressure", "Temperature"};
    hid_t       field_type[NFIELDS];
    hid_t       string_type;
    hid_t       file_id;
    hsize_t     chunk_size   = 10;
    Particle    fill_data[1] = {{"no data", -1, -1, -99.0f, -99.0}}; /* Fill value particle */
    int         compress     = 0;
    hsize_t     nfields;
    hsize_t     start;    /* Record to start reading/writing */
    hsize_t     nrecords; /* Number of records to read/write */
    int         i;

    /* Define new values for the field "Pressure"  */
    float pressure_in[NRECORDS_ADD] = {0.0f, 1.0f, 2.0f};
    int   field_index_pre[1]        = {3};
    int   field_index_pos[2]        = {1, 2};

    /* Define new values for the fields "Latitude,Longitude"  */
    Position position_in[NRECORDS_ADD] = {{0, 0}, {10, 10}, {20, 20}};

    size_t field_sizes_pos[2] = {sizeof(position_in[0].longi), sizeof(position_in[0].lati)};

    size_t field_sizes_pre[1] = {sizeof(float)};

    /* Initialize the field field_type */
    string_type = H5Tcopy(H5T_C_S1);
    H5Tset_size(string_type, 16);
    field_type[0] = string_type;
    field_type[1] = H5T_NATIVE_INT;
    field_type[2] = H5T_NATIVE_INT;
    field_type[3] = H5T_NATIVE_FLOAT;
    field_type[4] = H5T_NATIVE_DOUBLE;

    /* Create a new file using default properties. */
    file_id = H5Fcreate("ex_table_05.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);

    /* Make the table */
    H5TBmake_table("Table Title", file_id, TABLE_NAME, NFIELDS, NRECORDS, dst_size, field_names, dst_offset,
                   field_type, chunk_size, fill_data, compress, p_data);

    /* Write the pressure field starting at record 2 */
    nfields  = 1;
    start    = 2;
    nrecords = NRECORDS_ADD;
    H5TBwrite_fields_index(file_id, TABLE_NAME, nfields, field_index_pre, start, nrecords, sizeof(float), 0,
                           field_sizes_pre, pressure_in);

    /* Write the new longitude and latitude information starting at record 2  */
    nfields  = 2;
    start    = 2;
    nrecords = NRECORDS_ADD;
    H5TBwrite_fields_index(file_id, TABLE_NAME, nfields, field_index_pos, start, nrecords, sizeof(Position),
                           field_offset_pos, field_sizes_pos, position_in);

    /* read the table */
    H5TBread_table(file_id, TABLE_NAME, dst_size, dst_offset, dst_sizes, dst_buf);

    /* print it by rows */
    for (i = 0; i < NRECORDS; i++) {
        printf("%-5s %-5d %-5d %-5f %-5f", dst_buf[i].name, dst_buf[i].lati, dst_buf[i].longi,
               dst_buf[i].pressure, dst_buf[i].temperature);
        printf("\n");
    }

    /* close type */
    H5Tclose(string_type);

    /* close the file */
    H5Fclose(file_id);

    return 0;
}