void DtStackS1()
{
   TFile *_file0 = TFile::Open("data/EfficiencyHistos.root");

   TH1 * phDtPlotRaw;
   TH1 * phDtPlotSel;
   if( NULL != _file0 )
   {

      gDirectory->cd("Sts_Raw");

      phDtPlotRaw    = dynamic_cast< TH1 * >( gDirectory->FindObjectAny( "fhSetupSortedDtX1Y1X2Y2N1P1" ) );
      if( NULL == phDtPlotRaw )
         return;

      gDirectory->cd("../Sts_GeoCuts");
      phDtPlotSel    = dynamic_cast< TH1 * >( gDirectory->FindObjectAny( "fhDtBestPairsHodoS1GeoCut" ) );
      if( NULL == phDtPlotRaw )
         return;

   } // if( NULL != _file0 )
      else return;

   THStack * stackDt = new THStack( "hsDt", "Raw Hodo-S1 dt and selected one" );

   phDtPlotRaw->SetLineColor( kBlue );
   stackDt->Add( phDtPlotRaw );

   phDtPlotSel->SetLineColor( kRed );
   stackDt->Add( phDtPlotSel );

   stackDt->Draw( "nostack hist" );
   gPad->SetLogy();
   gPad->SetGridx();
   gPad->SetGridy();
}