/* NOTE - this is a root6 macro.  root5's way of accessing TTrees is a PITA */

#include "TFile.h"
#include "TTree.h"
#include "TH1D.h"
#include "TTreeReader.h"
#include "TTreeReaderValue.h"
#include "TTreeReaderArray.h"

using namespace std;

void Readbackup_muons() {

  // use TChain just to get list of files in directory

  TChain chain("NtpSt");
  std::string infilename;
  infilename = "muons-*.root";
  chain.Add(infilename.c_str());
  
  TObjArray* filelist = chain.GetListOfFiles(); 
  TIter iter(filelist); 
  

  // make two histograms;
  TH1D *zenHisto = new TH1D("zenHisto","zen",60,0.0,60.0);
  TH1D *aziHisto = new TH1D("azi","azi",60,0.0,60.0);
 

  // Loop over all files in chain element list until done selecting those 
  TChainElement* element = 0; 
  while ((element = dynamic_cast<TChainElement*>(iter.Next())) ) 
    { 
      cout<<" new input file "<<element->GetTitle()<<endl; 
       
      TFile* CondenseFile = new TFile(element->GetTitle()); 
      if ( !CondenseFile->IsOpen() || CondenseFile->IsZombie() )  
        { 
          cerr << "Warning! Failed to open file " << CondenseFile->GetName() << endl; 
          delete CondenseFile; 
          continue; 
        } 

      // make a tree reader instance: get the "data" tree out of CondenseFile
     
      TTreeReader muonReader("data", CondenseFile);

  // Let's look at number of tracks.  Things where there are one value per event are accessed like this

      TTreeReaderValue<Int_t> ntrack(muonReader, "ntrack")

     // Things where there's an array per event (in our case, could
      // be a lot of tracks) are accessed like this

      TTreeReaderArray<Double_t> zen(muonReader, "zen");
      TTreeReaderArray<Double_t> azi(muonReader, "azi");

      // Loop over all entries of the TTree
      while (muonReader.Next()) {
	// TTreeReaderValue's are accessed with the "*" dereference

	for (UChar_t i = 0; i < *ntrack; i++) {
	  // TTreeReaderArray's are accessed just straight up like this, fills in the data for length
	  zenHisto->Fill(zen[i]);
	  aziHisto->Fill(azi[i]);
	
    
      // free input tree stuff, close input file
      if (CondenseFile) { delete CondenseFile; CondenseFile = 0; } // also destructs input file tree
    
	}
		
  // drawing the histograms
  TCanvas* zenCanvas = new TCanvas("zenCanvas","zen",640,480);
  gPad->SetLogy();
  zenHisto->Draw();
  TCanvas* aziCanvas = new TCanvas("aziCanvas","azi",640,480);
  aziHisto->Draw();
}
	}
	}