{
   auto c1 = new TCanvas("c1","c1",600,600);
   c1->Divide(1,2);
   auto hcol21 = new TH2F("hcol21","Option COLZ",40,-4,4,40,-20,20);
   auto hcol22 = new TH2F("hcol22","Option COLZ0",40,-4,4,40,-20,20);
   float px, py;
   for (Int_t i = 0; i < 25000; i++) {
      gRandom->Rannor(px,py);
      hcol21->Fill(px,5*py);
      hcol22->Fill(px,5*py);
   }
   hcol21->SetBit(TH1::kNoStats);
   hcol22->SetBit(TH1::kNoStats);
   c1->cd(1); hcol21->Draw("COLZ");
   c1->cd(2); hcol22->Draw("COLZ0");
   hcol21->SetMaximum(100);
   hcol21->SetMinimum(40);
   hcol22->SetMaximum(100);
   hcol22->SetMinimum(40);
}