hist022_TH2_palette.C File Reference

Detailed Description

When an histogram is drawn with the option COLZ, a palette is automatically drawn vertically on the right side of the plot.

It is possible to move and resize this vertical palette as shown on the left plot. The right plot demonstrates that, when the width of the palette is larger than its height, the palette is automatically drawn horizontally.

 
void hist022_TH2_palette()
{
   auto c = new TCanvas("", "", 0, 0, 1100, 550);
   c->Divide(2, 1);
   gStyle->SetOptStat(0);
 
   auto h1 = new TH2D("h1", "h1", 40, -4, 4, 40, -20, 20);
   auto h2 = new TH2D("h2", "h2", 40, -4, 4, 40, -20, 20);
   float px, py;
   for (int i = 0; i < 25000; i++) {
      gRandom->Rannor(px, py);
      h1->Fill(px, 5 * py);
      gRandom->Rannor(px, py);
      h2->Fill(px, 5 * py);
   }
 
   TPad *p1 = (TPad *)c->cd(1);
   TPad *p2 = (TPad *)c->cd(2);
 
   p1->SetRightMargin(0.15);
   auto palette1 = new TPaletteAxis(4.05, -15, 4.5, 15, h1);
   h1->GetListOfFunctions()->Add(palette1);
 
   p2->SetBottomMargin(0.2);
   auto palette2 = new TPaletteAxis(-3., -25, 3., -23, h2);
   h2->GetListOfFunctions()->Add(palette2);
 
   p1->cd();
   h1->Draw("colz");
   p2->cd();
   h2->Draw("colz");
}

Date

October 2024

Author

Olivier Couet

Definition in file hist022_TH2_palette.C.