void efficiency()
  
{

  //TEfficiency* pEff = 0;
  TEfficiency* pEff = new TEfficiency("eff","my efficiency;x;#epsilon",20,0,10);
  TFile* f= new TFile("for_tefficiency.root","recreate");

  //TH1F *h1;
  //TH1F *h2;

  h1 = (TH1F*)f->Get("Num_p");
  h2 = (TH1F*)f->Get("Den_p");

  //h_pass and h_total are valid and consistent histograms
  TFile* pFile = new TFile("myfile.root","recreate");
  if(TEfficiency::CheckConsistency(*h1,*h2))
    {
      pEff = new TEfficiency(*h1,*h2);
      pEff->Write();
      pEff->Draw("AP");
    }
  
}



/*TEfficiency* pEff = 0;

TH1D *h_pass = new TH1D("h_pass","pass",10,0,10);
TH1D *h_tot = new TH1D("h_tot","tot",10,0,10);
for (int i=1;i<11;i++)
{
h_pass->SetBinContent(i,i);
h_tot->SetBinContent(i,2*i);
// no need to set the errors (they are automatically = sqrt(content) 
}
h_tot->Draw();
h_pass->Draw("same");
TFile* pFile = new TFile("myfile.root","recreate");
if(TEfficiency::CheckConsistency(*h_pass,*h_tot))
{
pEff = new TEfficiency(*h_pass,*h_tot);
pEff->Write();
pEff->Draw("AP");
}
}*/