hdf5 example code h5_rdwt.c does not work - c

Question

I have a problem running an example code from hdf5 called h5_rdwt.c (in eclipse). You can find this here:
http://www.hdfgroup.org/HDF5/Tutor/rdwt.html#rdwr
The code is:
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* 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 files COPYING and Copyright.html. COPYING can be found at the root *
* of the source code distribution tree; Copyright.html can be found at the *
* root level of an installed copy of the electronic HDF5 document set and *
* is linked from the top-level documents page. It can also be found at *
* http://hdfgroup.org/HDF5/doc/Copyright.html. If you do not have *
* access to either file, you may request a copy from help#hdfgroup.org. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* This example illustrates how to write and read data in an existing
* dataset. It is used in the HDF5 Tutorial.
*/
#include "hdf5.h"
#define FILE "dset.h5"
int main() {
hid_t file_id, dataset_id; /* identifiers */
herr_t status;
int i, j, dset_data[4][6];
/* Initialize the dataset. */
for (i = 0; i < 4; i++)
for (j = 0; j < 6; j++)
dset_data[i][j] = i * 6 + j + 1;
/* Open an existing file. */
file_id = H5Fopen(FILE, H5F_ACC_RDWR, H5P_DEFAULT);
/* Open an existing dataset. */
dataset_id = H5Dopen2(file_id, "/dset", H5P_DEFAULT);
/* Write the dataset. */
status = H5Dwrite(dataset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
dset_data);
status = H5Dread(dataset_id, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT,
dset_data);
/* Close the dataset. */
status = H5Dclose(dataset_id);
/* Close the file. */
status = H5Fclose(file_id);
}
Before I did so, I created a file named "dset.h5" with:
#include "hdf5.h"
#define FILE "dset.h5"
main() {
hid_t file_id; /* file identifier */
herr_t status;
/* Create a new file using default properties. */
file_id = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
/* Terminate access to the file. */
status = H5Fclose(file_id);
}
Building is no problem, but when I try to run this I get the message:
HDF5-DIAG: Error detected in HDF5 (1.8.11) thread 0:
#000: ../../src/H5D.c line 334 in H5Dopen2(): not found
major: Dataset
minor: Object not found
#001: ../../src/H5Gloc.c line 430 in H5G_loc_find(): can't find object
major: Symbol table
minor: Object not found
#002: ../../src/H5Gtraverse.c line 861 in H5G_traverse(): internal path traversal failed
major: Symbol table
minor: Object not found
#003: ../../src/H5Gtraverse.c line 641 in H5G_traverse_real(): traversal operator failed
major: Symbol table
minor: Callback failed
#004: ../../src/H5Gloc.c line 385 in H5G_loc_find_cb(): object 'dset' doesn't exist
major: Symbol table
minor: Object not found
HDF5-DIAG: Error detected in HDF5 (1.8.11) thread 0:
#000: ../../src/H5Dio.c line 234 in H5Dwrite(): can't prepare for writing data
major: Dataset
minor: Write failed
#001: ../../src/H5Dio.c line 266 in H5D__pre_write(): not a dataset
major: Invalid arguments to routine
minor: Inappropriate type
HDF5-DIAG: Error detected in HDF5 (1.8.11) thread 0:
#000: ../../src/H5Dio.c line 140 in H5Dread(): not a dataset
major: Invalid arguments to routine
minor: Inappropriate type
HDF5-DIAG: Error detected in HDF5 (1.8.11) thread 0:
#000: ../../src/H5D.c line 391 in H5Dclose(): not a dataset
major: Invalid arguments to routine
minor: Inappropriate type
Does someone know what went wrong?
Thank you!

Answer 1

The main routine in your program includes the lines
/* Open an existing dataset. */
dataset_id = H5Dopen2(file_id, "/dset", H5P_DEFAULT);
but there's no evidence from what you have posted that the file in question contains any datasets to open. You seem to have created a file called dset but that's not the same thing as a dataset. From what you've posted your file is empty.
The clue to this is given in the error report which states, inter alia
HDF5-DIAG: Error detected in HDF5 (1.8.11) thread 0:
#000: ../../src/H5D.c line 334 in H5Dopen2(): not found
major: Dataset
minor: Object not found

Answer 2

You have to create the dataset as well before accessing it. There is an example for that on the hdf5-page as well:
ftp://www.hdfgroup.org/HDF5/examples/introductory/C/h5_crtdat.c
Short: using H5Screate_simple to create dataspace and H5Dcreate2 to create the dataset.