is there a simple method to write the main info of an event (particle ID, momentum, energy, radLength, etc) generated in Geant4 into a .root-file? or can i just include a file where i build a root-tree in my geant4 file? Or rather embed Geant4 in ROOT?
as far as I know, the G4 team has realized that this needs to become a bit easier. So first of all I’d ask them (also to “register” that there are interested users). It would probably be easiest to fill a TNtuple in G4 and write that to a TFile. Alternatively you can work with the G4 team to get their event data (as G4 objects) written to a TFile.
If you really want to do it right then you create your own (set of) class(es) representing the G4 results and you fill them inside a TSelector loop. See tutorials/proof/ProofPythia.C for a non-input driven TSelector. The advantage of this approach is that you can use Proof (-lite), sending it off to a batch system or using all cores in parallel. Let us know if you are interested in this approach and we’ll implement an example setup together with you.
yeah, i wanted to post my question originally on the Geant forum but that didn’t work yesterday…
thanks a lot for your offer, for now i think my needs are rather simple, i don’t really want to generate huge data sets… so maybe i look if i find some easy and straight-forward way in the Geant forum and if not, i’ll contact you again!