Hello all,
After several days struggling with the HDF5 to ROOT conversion, I have created a program based on the original one posted by Giuseppe Vacanti:hdf2root.tar.gz (3.74 KB)
It converts the whole HDF5 structure into TTrees:
For every Group in the HDF5 file, hdf2root creates a TTree (named as the orginal Group) which stores the info contained in the original DataSets. Moreover, the Attributes of the Group are stored in another TTree (named as the original group plus “_att”), together with the Attributes of every DataSet in the Group.
The program is thought to work in any kind of HDF5 file and make a “general” conversion.
It works in all the data files I have tested, which amounts to 4 or 5 different types (only!).
A clear limitation would be how to handle more complex DataTypes. Up to know, only simple types are supported, but this could be enough for many users (it is actually enough for the files I have to handle!).
The usage is quite simple:
Usage: hdf2root [--seq] <inFile.h5> <outFile.root(default=inFile.root)>
--seq Enables sequential mode.hdf2root just needs the original HDF5 file as input to create a root file with the same name. If you want a different output name, put it in as a second argument. If the –seq is set, hdf2root create the TTrees for the DataSets in sequential mode. This means that the first dimension of the data set is used like an “event index” (if you know what I mean…).
I aim you (interested people) to take a look and send some feedback.
One could start with the example file I posted in a previous post in this thread (gamma.h5).
Warning: I am only experiencing problems with the conversion of hdf5_strings mostly present in Attributes.
The size of these objects is not 1 to 1 with their length and, as a result, larger strings of characters are stored in root unnecessarily. This could be a problem of the particular hdf5 files I am using, instead of the converter itself.
I hope it helps to the community.
Cheers,
Alberto