Writing Compound Data to an Existing HDF5 file

I'm having difficulty adding a new compound dataset to an existing hdf5 file.

I get an error along the lines of:

***********************

Error using hdf5lib2 The HDF5 library encountered an error during execution of the 'H5Dcreate1' function, 'unable to create dataset'.

Error in H5D.create (line 40) id = H5ML.hdf5lib2('H5Dcreate', varargin{:} );

**************************

The easiest way to recreate this error is using the example script for writing MATLAB compound data to a hdf5 file on the hdfgroup.org website: http://www.hdfgroup.org/ftp/HDF5/examples/examples-by-api/matlab/HDF5_M_Examples/h5ex_t_cmpd.m

Basically, I run the script once so it create a file. Then I change

DATASET = 'DS1';

to

DATASET = 'DS2';

and

file = H5F.create(fileName);

to

file = H5F.open (fileName);

The aim is to create an identical dataset called DS2 inside of the same file as DS1. However, MATLAB throws the above error.

Any ideas what I'm doing wrong?

Answer 1

[John]

You are opening the file in read-only mode, which is why the H5D.create call fails. Check the help for H5F.open, it has an example of what you need to do to modify your code.

[Simon]

Thanks again, John!