#ifdef __CLING__
R__LOAD_LIBRARY(libDelphes)
#include "classes/DelphesClasses.h"
#include "external/ExRootAnalysis/ExRootTreeReader.h"
#endif

//------------------------------------------------------------------------------

void SampleMacro(const char *inputFile0,const char *inputFile1){

   gSystem->Load("libDelphes");  

   TCanvas *c1 = new TCanvas("Photon PT");
   TCanvas *c2 = new TCanvas("Photon E");

   TH1 *histPhotonPT[2];
   TH1 *histPhotonE [2];

   TLegend *legend1 = new TLegend(0.2,0.2,0.4,0.33);
   TLegend *legend2 = new TLegend(0.2,0.2,0.4,0.33);


	for(int nfile=0; nfile<2; nfile++){

	const char *inputFile;
	if(nfile==0){inputFile = inputFile0;}	
	if(nfile==1){inputFile = inputFile1;}

  // Create chain of root trees
  TChain chain("Delphes");
  chain.Add(inputFile);
  
  // Create object of class ExRootTreeReader
  ExRootTreeReader *treeReader = new ExRootTreeReader(&chain);
  Long64_t numberOfEntries = treeReader->GetEntries();
  
  // Get pointers to branches used in this analysis
  TClonesArray *branchPhoton = treeReader->UseBranch("Photon");  


  // Book histograms
   histPhotonPT[nfile] = new TH1F("photon_pt", "P_{T}(#gamma)", 100, 0.0, 500.0);
   histPhotonE[nfile]= new TH1F("photon_energy", "E(#gamma)", 100, 0.0, 500.0);

//   histPhotonPT[nfile]->SetStats(1);

   Photon *photon;
   MissingET *misset;


  // Loop over all events
  for(Int_t entry = 0; entry < numberOfEntries; ++entry)
  {
    // Load selected branches with data from specified event
    treeReader->ReadEntry(entry);
  
    // If event contains at least 1 photon
    if(branchPhoton->GetEntries() > 0)
    {
      // Take first photon
      photon = (Photon*) branchPhoton->At(0);
      
      histPhotonPT[nfile]->Fill(photon->PT);
      histPhotonE[nfile]->Fill(photon->E);
     }
   }

    }// number loop

//   histPhotonPT[0]->SetStats(1);
//   histPhotonPT[1]->SetStats(1);

   c1->SetLogy();
   c1->SetTickx();
   c1->SetTicky();
   c1->SetGrid();
   c2->SetLogy();
   c2->SetTickx();
   c2->SetTicky();
   c2->SetGrid();

  c1->cd();
   histPhotonPT[0]->SetLineColor(kRed);
   histPhotonPT[0]->Draw();
   histPhotonPT[1]->SetLineColor(kBlack);
   histPhotonPT[1]->Draw("same");
   legend1->AddEntry(histPhotonPT[0],"Signal","f");
   legend1->AddEntry(histPhotonPT[1],"Background","f");
   legend1->Draw();

  c2->cd();
   histPhotonE[0]->SetLineColor(kRed);
   histPhotonE[0]->Draw();
   histPhotonE[1]->SetLineColor(kBlack);
   histPhotonE[1]->Draw("same");
   legend2->AddEntry(histPhotonE[0],"Signal","f");
   legend2->AddEntry(histPhotonE[1],"Background","f");
   legend2->Draw();

}