void trySimulation(){
  
  Int_t eMin = 7;

  TTimeStamp time;
  TRandom3 rand(time.GetTime());

  TH1F * h1 = new TH1F("h1", "h1", 100, 0., 1.);

  Int_t nEvts = 5000000;

  Float_t fpE = 0.307;
  Float_t fpEerr = 0.03;

  Float_t eBin = Float_t(eMin);

  for(Int_t j = 0; j < nEvts; j++){
    Float_t E =eBin+rand.Uniform(0., 1.); 
    Float_t Npe = 4.85*E; 
    Int_t n = rand.Poisson(Npe);

    Float_t fp = rand.Gaus(fpE, fpEerr);
    
    Int_t n1 = rand.Binomial(n, fp);

    h1->Fill(Float_t(n1)/n);
  }

  h1->Scale(1000./h1->GetEntries());
  h1->SetLineWidth(2);
  h1->SetLineColor(2);
  h1->Draw();
}