// Example displaying a 2D histogram with its two projections.

{
   TCanvas *c1 = new TCanvas("c1", "c1",900,900);
    
   gStyle->SetOptStat(0);
   

   
   // Create, fill and project a 2D histogram.
   TH1D *h1 = new TH1D("h1","",100, 0, 10);

   TH2F *h2 = new TH2F("h2","",100, 0, 3.5, 100, 0, 3.5);
   h2->GetXaxis()->SetTitle("M^{2}_{K^{-}#pi^{+}} [GeV^{2}/c^{4}]");
   h2->GetYaxis()->SetTitle("M^{2}_{K^{-}#pi^{0}} [GeV^{2}/c^{4}]");
   h2->GetXaxis()->SetTitleSize(0.04);
   h2->GetYaxis()->SetTitleSize(0.04);
   h2->SetMarkerStyle(7);
   h2->GetXaxis()->CenterTitle();
   h2->GetYaxis()->CenterTitle();
   
   // TH1D *h3 = new TH1D("h3","",100, 0, 3.5);


    
   TFile *f1 = new TFile("script_read_RS_mc14ri_1ab_light-2112-uranus_with_MD0_cut.root");
   TTree *tree1  = (TTree*)f1->Get("DstD0PiKPiPi0RS_withcut");
   Double_t  deltaM;
   tree1->SetBranchAddress("deltaM",&deltaM);


   TFile *f2 = new TFile("output.root");
   TTree *tree2  = (TTree*)f2->Get("tree");
   Double_t  Weight;
   tree2->SetBranchAddress("Weight",&Weight);
  

   Int_t nentries = (Int_t)tree1->GetEntries();
    for (Int_t i=0; i<nentries; i++)
      {
        tree1->GetEntry(i);   
        {
         h1->Fill(deltaM,Weight);
         // cout<< "GetBinContent =" << h1->GetBinContent(i) << endl; 
        }
      }

    h1->Draw("HIST");
  
}