Re: TTree -> TChain
Rene Brun (Rene.Brun@cern.ch)
Mon, 06 Apr 1998 15:39:24 +0200
Laurent Aphecetche wrote:
>
> Hi happy ROOTERS !
>
> I've got a problem when trying to go from trees to chains :
>
> //1 TFile* f = new TFile("a702minbiaspion.root") ;
> //1 TTree* EM = (TTree*)f->Get("EM");
>
> //2 TChain* EM = new TChain("EM") ;
> //2 EM->Add("a702minbiaspion.root") ;
>
> RBEvent *event = new RBEvent ;
> UInt_t fHeader_fTrigger;
> Int_t fNparticleEM;
>
> EM->SetBranchAddress("event",&event);
> EM->SetBranchAddress("fHeader.fTrigger",&fHeader_fTrigger);
> EM->SetBranchAddress("fNparticleEM",&fNparticleEM);
>
> EM->SetBranchStatus("*",1) ;
>
> Int_t i ;
> Int_t n=0 ;
> for (i=0;i<5;i++) {
> n += EM->GetEvent(i,1) ;
> printf("n=%d fNparticleEM=%d fHeader_fTrigger=%x\n",n,fNparticleEM,
> fHeader_fTrigger) ;
> }
>
> The case 1 gives me what is expected, i.e. sth like :
>
> n=483 fNparticleEM=2 fHeader_fTrigger=26008200
> n=1080 fNparticleEM=2 fHeader_fTrigger=26008000
> n=1563 fNparticleEM=2 fHeader_fTrigger=26008200
> n=2198 fNparticleEM=2 fHeader_fTrigger=600c600
> n=2833 fNparticleEM=2 fHeader_fTrigger=26008000
>
> But case 2 gives :
>
> n=483 fNparticleEM=0 fHeader_fTrigger=0
> n=1080 fNparticleEM=0 fHeader_fTrigger=0
> n=1563 fNparticleEM=0 fHeader_fTrigger=0
> n=2198 fNparticleEM=0 fHeader_fTrigger=0
> n=2833 fNparticleEM=0 fHeader_fTrigger=0
>
> What am I missing ?
Hi Laurent,
Thanks for reporting this problem with TChain::SetBranchAddress
in version 2.00.
This problem is now fixed in our development version 2.00/04
that will be available either tomorrow or Wednesday.
Rene Brun