Re: [ROOT] Update Tree Branch

From: Volker Hejny (V.Hejny@fz-juelich.de)
Date: Tue Aug 21 2001 - 09:03:55 MEST


Hi,

On Mon, Aug 20, 2001 at 07:32:12PM -0700, Mark Polsen wrote:
> I have a questions about Tree branches that I cannot find an answer to in the 
> documentation or mailing list. I'm currently using Root Trees to write event 
> information in my Geant4 simulation at the end of each event. I write out hit 
> information, run and event numbers, etc...
> 
> I've added additional branches to record track information. Is there a way 
> that I can only update the individual branches (containing track information) 
> without having to update entire tree (without updating event information)?

It is possible to fill the branches seperately, but I'm not sure if
this will help you. In the best case, you will just have more entries
in the track branch than in the event branch and you have to match
it.

What we are doing in the same situation is to save the track information 
in a TClonesArray holding one track per object. At the end of the event 
this is written to file together with the detector response and main
event information with a single TTree::Fill(). 

Best regards,
Volker

-- 
Dr. Volker Hejny                Tel: 02461/616853                      ** 
Institut f. Kernphysik          Fax: 02461/613930                     **
---------------------------------------------------------------- **  ** ---  
Forschungszentrum Juelich GmbH, D-52425 Juelich                    **



This archive was generated by hypermail 2b29 : Tue Jan 01 2002 - 17:50:58 MET