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Entry  05 Dec 2003, Konstantin Olchanski, , HOWTO setup MIDAS ROOT tree analysis 
    Reply  20 Jul 2004, Konstantin Olchanski, , HOWTO setup MIDAS ROOT tree analysis 
Message ID: 33     Entry time: 20 Jul 2004     In reply to: 32
Author: Konstantin Olchanski 
Topic:  
Subject: HOWTO setup MIDAS ROOT tree analysis 
Updating the instructions to ROOT version 3.10.2. Example is from TRIUMF-KOPIO
tree analysis.

shell> root -l
root> TFile *f = new TFile("run00064.root")
root> Trigger->MakeSelector("TriggerSelector")  // "Trigger" is the tree name
inside the root file. Generates TriggerSelector.h and TriggerSelector.cpp

= edit run.C, the main program:

{
gROOT->Reset();
TSelector *s = TSelector::GetSelector("TriggerSelector.C");

TChain chain("Trigger"); // "Trigger" is the tree name inside the root files
chain.Add("run03016.root"); // can chain multiple files

TH1D* tdc2 = new TH1D("tdc2","TDC2",1500,0,1500-1);

chain.Process(s,"",500); // process 500 events
//chain.Process(s); // or process all events

tdc2->Draw();
}

= edit TriggerSelector.h:

in the TriggerSelector class members, i.e. "UInt_t TDC1_TDC1[47];" edit the
array size to be bigger than the maximum possible bank size

= edit TriggerSelector.C:

Bool_t TriggerSelector::Process(Int_t entry)
{
  fChain->GetTree()->GetEntry(entry);

  if (entry%100 == 0)
    printf("process %d, nTDC %3d, 0x%08x\n",entry,TDC1_nTDC1,TDC1_TDC1[1]);

  tdc2->Fill(TDC1_nTDC1);
  return kTRUE;
}

= Run the analysis:

shell> root -l
root> .x run.C
 
K.O.
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