Re: TNtuples in TTrees

From: Rene Brun (Rene.Brun@cern.ch)
Date: Tue Sep 21 1999 - 16:10:26 MEST


Hi Nigel,
You can have a TNtuple as a branch of a TTree, but you should not use
the split mode (see list of restrictions for the automatic split mode).
You code should be:

   TNtuple nt("ntuple","Big Ntuple","run:evt:sen");
   TTree *acc=new TTree("acc","Acceptance");
   TBranch *br_nt;
   br_nt=acc->Branch("ntuple","TNtuple",&nt,32000,0);

Rene Brun

PS. I never though of this idea. This could be an interesting feature in
the
case that all TNtuple data are in memory.



nigel@kiwi.chm.bnl.gov wrote:
> 
> Dear Roottalk,
>               I tried to put a TNtuple into a TTree, using the following
> code
> 
>    TNtuple nt("ntuple","Big Ntuple","run:evt:sen");
>    TTree *acc=new TTree("acc","Acceptance");
>    TBranch *br_nt;
>    br_nt=acc->Branch("ntuple","TNtuple",&nt);
> 
> and got the following responce
> 
> Error in <TClass::New>: no default ctor for class TPacketGenerator
> 
>  *** Break *** segmentation violation
> 
> Does this mean it is impossible to put TNtuples into TTrees? TNtuple
> is derived from TObject so why doesn't this work?
> 
>                         Thanks
>                         Nigel



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