void tcutgdemo()
{

  gStyle->SetPalette(1);
  
delete gROOT->GetFile("cuttest.root");
TFile *f = TFile::Open("cuttest.root");
TTree *tree;
  if (!f ) {
    f = new TFile("cuttest.root","recreate");

      tree= new TTree("bigtree","bigtree");
      Float_t mipposemc[2];
      tree->Branch("mipposemc",mipposemc,"mipposemc[2]/F");
      for ( Int_t i=-95; i<100; i += 10 ) {
	for ( Int_t j=-95; j<100; j += 10 )
	  {
	    mipposemc[0]=i;
	    mipposemc[1]=j;
	    tree->Fill();
	  }
      }
      tree->Write();
      delete f;
      cout << "TTree bigtree not found" << endl;
      //      return;
   } else {
     tree = (TTree*)f->Get("bigtree");
   }

  
  
  double ulx[4] = {40.,-2.,40.,40.};
  double uly[4] = {10., 70.,70., 0.};

  double lrx[4]={-60,-20,-60,-60};
  double lry[4]={ 20,-50,-50, 20};
  
  TCutG* upperleft = new TCutG( "upperleft" , 4, uly, ulx );
  TCutG* lowerright= new TCutG( "lowerright", 4, lry, lrx );

  upperleft->SetVarX("mipposemc[0]");
  upperleft->SetVarY("mipposemc[1]");
  lowerright->SetVarX("mipposemc[0]");
  lowerright->SetVarY("mipposemc[1]");


  c1 = new TCanvas( "c1","c1");

  TH2F* ulhist = new TH2F("ulhist","ulhist",20,-100,100,20,-100,100);
  TH2F* lrhist = new TH2F("lrhist","lrhist",20,-100,100,20,-100,100);

  //  tree->Draw("mipposemc[0]:mipposemc[1]>>ulhist","mipposemc[0]>10&&upperleft","colz");
  tree->Draw("mipposemc[0]:mipposemc[1]>>ulhist","mipposemc[0]>10&&upperleft","box");
  tree->Draw("mipposemc[0]:mipposemc[1]>>lrhist","mipposemc[0]<-10&&lowerright","box");

  ulhist->Draw("colz");
  lrhist->Draw("colz same");

  //  delete upperleft;
  //  delete lowerright;
  

}