//
{
  cout << " Executing Electron Analysis Macro." << endl;
  
  // Clean up :
  gROOT->Reset();
  // gStyle->SetFrameFillColor(42);
  // gROOT->SetStyle("Plain");

  char *s = new char[1];
 
  // Electron file :
  TFile electronFile("electrons.root");

  // List the contents :
  electronFile->cd("HighPtElectrons");
  electronFile->ls();
  
  TTree* electronNtuple = (TTree*) ElectronNtuple;
  
  electronNtuple->Print();

  // Set up the canvas and pads :
  // Make a canvas to plot the histograms on :
  c1 = new TCanvas("c1","Electron analysis",0,0,700,900);
  c1->SetFillColor(18);
  // c1->SetHighLightColor(0);
  // Make the pads for the individual histograms.
  // The coordinates are (x,y) of the bottom-left-hand and upper-right-hand
  // corners, respectively :
  pad1 = new TPad("pad1"," ",0.01,0.51,0.49,0.99,21);
  pad2 = new TPad("pad2"," ",0.51,0.51,0.99,0.99,21);
  pad3 = new TPad("pad3"," ",0.01,0.01,0.49,0.49,21);
  pad4 = new TPad("pad4"," ",0.51,0.01,0.99,0.49,21);
  pad1->Draw();
  pad2->Draw();
  pad3->Draw();
  pad4->Draw();
  pad1->SetFillColor(19);
  // pad1->SetBorderMode(0.);
  pad1->SetGrid();
  pad2->SetFillColor(19);
  // pad2->SetBorderMode(0.);
  pad2->SetGrid();
  pad3->SetFillColor(19);
  // pad3->SetBorderMode(0.);
  pad3->SetGrid();
  pad4->SetFillColor(19);
  // pad4->SetBorderMode(0.);
  pad4->SetGrid();

  // Set common line attributes :
  electronNtuple->SetLineColor(1);
  electronNtuple->SetLineWidth(2);

  pad1->cd();
  electronNtuple->Draw("ElecEt","ElecReg==1");
  pad2->cd();
  electronNtuple->Draw("ElecNShwrMax","ElecReg==1");
  // pad3->cd();
  // electronNtuple->Draw("nPes2dCluster");
  // pad4->cd();
  // electronNtuple->Draw("nPes2dCluster","ElecReg==1");
  pad3->cd();
  electronNtuple->SetLineStyle(2);
  electronNtuple->Draw("ElecEta","ElecReg==1 && ElecNShwrMax == 0");
  electronNtuple->SetLineStyle(1);
  electronNtuple->Draw("ElecEta","ElecReg==1 && ElecNShwrMax > 0","same");

  pad4->cd();
  electronNtuple->Draw("ElecPhi","ElecReg==1 && ElecNShwrMax > 0");
  electronNtuple->SetLineStyle(2);
  electronNtuple->Draw("ElecPhi","ElecReg==1 && ElecNShwrMax == 0","same");
  electronNtuple->SetLineStyle(1);

  c1->Update();

  // Try looping through the events in the ntuple to calculate efficiencies etc :
  Int_t nEvent = electronNtuple->GetEntries();  
  cout << " Looping over the " << nEvent << " events in electronNtuple : " << endl;
  TBranch* elecBranch = electronNtuple->GetBranch("ELEC");
  TBranch* plugBranch = electronNtuple->GetBranch("PLUG");

  int nGoodPlug = 0;
  int nGoodPlugWithShwrMax = 0;
  int nGoodPlugMissed = 0;

  for (Int_t iEvent = 0; iEvent < nEvent; iEvent++)
    {
      // cout << " Reading event " << iEvent << endl;
      electronNtuple->GetEvent(iEvent);
      // elecBranch->Print();
      int nElec = elecBranch->GetLeaf("nElec")->GetValue();
      // cout << " nElec = " << nElec << endl;
      // Alternatively, get the length of the array for any of the block variables :
      // cout << " GetLen = " << elecBranch->GetLeaf("ElecEta")->GetLen() << endl;
      for (int elecIndex = 0; elecIndex < nElec; elecIndex++)
	{
	  int elecReg      = elecBranch->GetLeaf("ElecReg")->GetValue(elecIndex);
	  float elecEt     = elecBranch->GetLeaf("ElecEt")->GetValue(elecIndex);
	  float elecEta    = elecBranch->GetLeaf("ElecEta")->GetValue(elecIndex);
	  int elecNShwrMax = elecBranch->GetLeaf("ElecNShwrMax")->GetValue(elecIndex);
	  // cout << " elecEt  = " << elecEt << endl;
	  // cout << " elecEta = " << elecEta << endl;
	  // cout << " elecReg = " << elecReg << endl;
	  int nPes2dCluster = plugBranch->GetLeaf("nPes2dCluster")->GetValue();

	  if (elecReg == 1 && elecEt > 20.0 && fabs(elecEta) < 2.5)
	    {

	      // This plug electron enters the denominator :
	      nGoodPlug += 1;
	      if (elecNShwrMax > 0)
		{
		  // This plug electron enters the numerator :
		  nGoodPlugWithShwrMax += 1;
		}
	      if (nPes2dCluster > 0 && elecNShwrMax == 0)
		{
		  // This plug electron missed possible matching Pes2dClusters :
		  nGoodPlugMissed += 1;
		}

	    }
	}
    }

  float matchingFraction = 0.;
  if (nGoodPlug != 0) matchingFraction = (1.0*nGoodPlugWithShwrMax)/(1.0*nGoodPlug);
  float missedFraction = 0.;
  if (nGoodPlugWithShwrMax != 0) missedFraction = (1.0*nGoodPlugMissed)/(1.0*nGoodPlugWithShwrMax);
  cout << endl << " Results of plug electron analysis : " 
       << endl << " =================================== " << endl;
  cout << " Fraction with matched Pes2dClusters = " << matchingFraction << endl;
  cout << " Fraction with missed Pes2dClusters  = " << missedFraction << endl << endl;
  


}