{
   auto c = new TCanvas("c","Example of col plots with option SAME",200,10,700,500);
   auto h1 = new TH2F("h1","h1",40,-3,3,40,-3,3);
   auto h2 = new TH2F("h2","h2",40,-3,3,40,-3,3);
   auto h3 = new TH2F("h3","h3",40,-3,3,40,-3,3);
   auto h4 = new TH2F("h4","h4",40,-3,3,40,-3,3);
   h1->SetBit(TH1::kNoStats);
   for (Int_t i=0;i<5000;i++) {
      double x,y;
      gRandom->Rannor(x,y);
      if(x>0 && y>0) h1->Fill(x,y,4);
      if(x<0 && y<0) h2->Fill(x,y,3);
      if(x>0 && y<0) h3->Fill(x,y,2);
      if(x<0 && y>0) h4->Fill(x,y,1);
   }
   h1->Draw("colz");
   h2->Draw("col same");
   h3->Draw("col same");
   h4->Draw("col same");
}