hist018_TH2_cutg.C

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/// \file
/// \ingroup tutorial_hist
/// \notebook -js
/// \preview This example demonstrates how to display a 2D histogram and
/// use TCutG object to select bins for drawing.
/// Moving TCutG object one can change displayed region of histogram
///
/// \macro_image
/// \macro_code
///
/// \date January 2023
/// \author Sergey Linev
 
void hist018_TH2_cutg()
{
   const int n = 6;
   Float_t x[6] = {1, 2, 1, -1, -2, -1};
   Float_t y[6] = {2, 0, -2, -2, 0, 2};
   TCutG *cut = new TCutG("cut", 6, x, y);
   TH2F *hist = new TH2F("hist", "Histogram with cut", 40, -10., 10., 40, -10., 10.);
   for (int i = 0; i < 100000; i++)
      hist->Fill(gRandom->Gaus(0., 3.), gRandom->Gaus(0., 3.));
   TCanvas *c1 = new TCanvas("c1", "Histogram draw with TCutG", 600, 900);
   hist->Draw("col [cut]");
   cut->Draw("l");
}