void EffStudy_Plots_mass()
{
 
  TFile *f = new TFile("DY_200to3000_EE_74X_forDZ_Tree.root");
  
	TTree *t = new TTree;
	t = (TTree*)f->Get("n1tree");

	double genWeight;
	double lumi_Weight;
	double Ele1PT;
	double Ele2PT;
	int Ele1MediumID;
	int Ele2MediumID;
	int Ele1DZId;
	int Ele2DZId;
	double mass;

	t->SetBranchAddress("genWeight", &genWeight);
	t->SetBranchAddress("lumi_Weight", &lumi_Weight);
	t->SetBranchAddress("Ele1PT",&Ele1PT);
	t->SetBranchAddress("Ele2PT",&Ele2PT);
	t->SetBranchAddress("Ele1MediumID",&Ele1MediumID);
	t->SetBranchAddress("Ele2MediumID",&Ele2MediumID);
	t->SetBranchAddress("Ele1DZId",&Ele1DZId);
	t->SetBranchAddress("Ele2DZId",&Ele2DZId);
	t->SetBranchAddress("mass",&mass);

	//	double NewBins[24] = {10,50,200,250,300,350,400,450,500,550,600,650,700,750,800,900,1000,1100,1200,1300,1400,1500,1600,1700};
		double NewBins[12] = {50,200,300,400,500,600,800,1000,1200,1400,1600,1700};

                Double_t xbins[16] = {200,250,300,350,400,450,500,550,600,650,700,750,800,1000,1500,3000};
		

	TH1F *numPT = new TH1F("numPT","Medium ID",11,NewBins);
	TH1F *numPTnoDZ = new TH1F("numPTnoDZ","DZ Masking",11,NewBins);
	TH1F *numMass = new TH1F("numMass","Medium ID",15,xbins);
	TH1F *numMassnoDZ = new TH1F("numMassnoDZ","DZ Masking",15,xbins);

	
	 int nentries = t->GetEntries();
        cout<<"entries: "<<nentries<<endl;
        for (unsigned int k=0; k < nentries; k++) {
             t->GetEntry(k);

	     if(Ele1MediumID == 1 && Ele2MediumID == 1)
	       {
		 numPT->Fill(Ele1PT,genWeight*lumi_Weight);
		 numPT->Fill(Ele2PT,genWeight*lumi_Weight);
		 numMass->Fill(mass,genWeight*lumi_Weight);
	       }

	     if(Ele1DZId == 1 && Ele2DZId  == 1)
	       {
		 numPTnoDZ->Fill(Ele1PT,genWeight*lumi_Weight);
		 numPTnoDZ->Fill(Ele2PT,genWeight*lumi_Weight);
		 numMassnoDZ->Fill(mass,genWeight*lumi_Weight);
	       }
	     
	}
	

		for(int i = 1; i <= numMass->GetXaxis()->GetNbins(); i++) {
	    	  cout << " Numerator = " << numMass->GetBinContent(i) << "   " << " Deominator = " << numMassnoDZ->GetBinContent(i) << "   " << "Efficiency =  " << numMass->GetBinContent(i)/numMassnoDZ->GetBinContent(i) <<  endl; }


	
	//============================================================== mass graph =================
	TMultiGraph *mg1 = new TMultiGraph();
	TGraphAsymmErrors* grl1 = new TGraphAsymmErrors();	
	grl1->BayesDivide(numMass,numMassnoDZ,"");
	grl1->SetMarkerColor(kRed);
	grl1->SetMarkerStyle(21);
	grl1->SetMarkerSize(1.2);
	grl1->GetXaxis()->SetTitle("Electron Pt");
	grl1->GetYaxis()->SetTitle("Ratio of Id Eff");
	grl1->GetYaxis()->SetTitleSize(0.05);
	grl1->GetYaxis()->SetTitleOffset(1.5);
	
	mg1->SetTitle("Ratio of Id Eff;Mass; DZ Efficiency");
	TCanvas *c1 = new TCanvas("c1","",200,10,600,500);
        c1->SetGridx();
        c1->SetGridy();
	mg1->Draw("APE");
        mg1->SetMinimum(0.5);
        mg1->SetMaximum(1.015);
	mg1->GetXaxis()->CenterTitle(0);
	mg1->GetXaxis()->SetTitleOffset(1.2);   
	mg1->GetYaxis()->CenterTitle(1);
	mg1->GetYaxis()->SetTitleOffset(1.4);
	
	
	 	 c1->SaveAs("EffMass_DZMasking_200to3000.png");

		
}