{
	//my test root file
   TFile *f = TFile::Open("test.root");
   f.ls();
   TH2D * h1 = (TH2D*)f.Get("test");

   TCanvas *c1 = new TCanvas("c1","c1",700,500);
   h1->Draw("COLZ0");

	//root example code
   TCanvas *c2 = new TCanvas("c2","c2",600,600);
   c2->Divide(1,2);
   TH2D *hcol21 = new TH2D("hcol21","Option COLZ",40,-4,4,40,-20,20);
   TH2D *hcol22 = new TH2D("hcol22","Option COLZ0",40,-4,4,40,-20,20);
   Float_t 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);
   gStyle->SetPalette(1);
   c2->cd(1); hcol21->Draw("COLZ");
   c2->cd(2); hcol22->Draw("COLZ0");
   hcol22->SetMaximum(100);
   hcol22->SetMinimum(40);

}