h5ex_d_rdwr.c

/************************************************************

  This example shows how to read and write data to a
  dataset.  The program first writes integers to a dataset
  with dataspace dimensions of DIM0xDIM1, then closes the
  file.  Next, it reopens the file, reads back the data, and
  outputs it to the screen.

 ************************************************************/

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

#define FILENAME "h5ex_d_rdwr.h5"
#define DATASET  "DS1"
#define DIM0     4
#define DIM1     7

int
main(void)
{
    hid_t   file  = H5I_INVALID_HID;
    hid_t   space = H5I_INVALID_HID;
    hid_t   dset  = H5I_INVALID_HID;
    herr_t  status;
    hsize_t dims[2] = {DIM0, DIM1};
    int     wdata[DIM0][DIM1]; /* Write buffer */
    int     rdata[DIM0][DIM1]; /* Read buffer */
    hsize_t i, j;

    /*
     * Initialize data.
     */
    for (i = 0; i < DIM0; i++)
        for (j = 0; j < DIM1; j++)
            wdata[i][j] = i * j - j;

    /*
     * Create a new file using the default properties.
     */
    file = H5Fcreate(FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);

    /*
     * Create dataspace.  Setting maximum size to NULL sets the maximum
     * size to be the current size.
     */
    space = H5Screate_simple(2, dims, NULL);

    /*
     * Create the dataset.  We will use all default properties for this
     * example.
     */
    dset = H5Dcreate(file, DATASET, H5T_STD_I32LE, space, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);

    /*
     * Write the data to the dataset.
     */
    status = H5Dwrite(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, wdata[0]);

    /*
     * Close and release resources.
     */
    status = H5Dclose(dset);
    status = H5Sclose(space);
    status = H5Fclose(file);

    /*
     * Now we begin the read section of this example.
     */

    /*
     * Open file and dataset using the default properties.
     */
    file = H5Fopen(FILENAME, H5F_ACC_RDONLY, H5P_DEFAULT);
    dset = H5Dopen(file, DATASET, H5P_DEFAULT);

    /*
     * Read the data using the default properties.
     */
    status = H5Dread(dset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, rdata[0]);

    /*
     * Output the data to the screen.
     */
    printf("%s:\n", DATASET);
    for (i = 0; i < DIM0; i++) {
        printf(" [");
        for (j = 0; j < DIM1; j++)
            printf(" %3d", rdata[i][j]);
        printf("]\n");
    }

    /*
     * Close and release resources.
     */
    status = H5Dclose(dset);
    status = H5Fclose(file);

    return 0;
}