Currently, the HDF5 capabilities of GNU Octave are very limited and are not generally useful for loading large HDF5 files from arbitrary sources. We are not currently aware of an Octave HDF5 interface that is currently maintained and works with current versions of Octave.

The HDF5 capabilities of Octave are limited because the only way to load HDF5 files is to greedily load the entire file into a “struct” via the load() command. The save('-hdf5') command puts the HDF5 variables into an arbitrary group layout that may not be useful for your project.

A possible alternative would be to use Octave NetCDF4. NetCDF4 is a subset of HDF5. Such a file format change would have to be with concurrence of others on your project.