Hi Rooters!
I was trying to read (and draw from) a tree which has members named
"event", "ptot" and many more. when i try to read them in the following
way:
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{
TChain t("trktree");
t->Add("/scratch3/munir/mini/run09666tree2.root");
TH1F *pid1 = new TH1F("pid1","ptot", 100,0,10);
TH1F *pid2 = new TH1F("pid2","events", 200,3000,5000);
t->Draw("ptot >> pid1");
t->Draw("event >> pid2");
}
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things work fine.
BUT, when i do the following
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{
Float_t ptot,event;
TFile *f = new TFile("/scratch3/munir/mini/run09666tree2.root");
TTree *trktree = (TTree *) f->Get("trktree");
TH1F *pid1 = new TH1F("pid1","ptot", 100,0,10);
TH1F *pid2 = new TH1F("pid2","events", 200,3000,5000);
Int_t nrow = trktree->GetEntries();
for (Int_t i =0; i < nrow; i++)
{
trktree->GetEntry(i);
trktree->SetBranchAddress("event", &event);
trktree->SetBranchAddress("ptot", &ptot);
pid1->Fill(ptot);
pid2->Fill(event);
}
}
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ptot is ok, BUT ALL ENTRIES FOR "event" ARE 0!!!
I really have no clue why is this happening. I'd really appreciate if
anyone could point me where i am commiting mistake.
Regards,
-munir
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M. MUNIRuzzaman
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Graduate Student |email: |Phone:
Department of Physics |munir@bnl.gov |(909)-787-7401
University of California | |(909)-276-4703(Home)
Riverside, CA 92521 |web: |
USA |www.phenix.bnl.gov/~munir |
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