histpalettecolor.C

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/// \file
/// \ingroup tutorial_hist
/// \notebook
/// Palette coloring for histogram is activated thanks to the options `PFC`
/// (Palette Fill Color), `PLC` (Palette Line Color) and `AMC` (Palette Marker Color).
/// When one of these options is given to `TH1::Draw` the histogram get its color
/// from the current color palette defined by `gStyle->SetPalette(...)`. The color
/// is determined according to the number of objects having palette coloring in
/// the current pad.
///
/// In this example five histograms are displayed with palette coloring for lines and
/// and marker. The histograms are drawn with makers and error bars and one can see
/// the color of each histogram is picked inside the default palette `kBird`.
///
/// \macro_image
/// \macro_code
///
/// \author Olivier Couet

void histpalettecolor()
{
   auto C = new TCanvas();

   gStyle->SetOptTitle(kFALSE);
   gStyle->SetOptStat(0);

   auto h1 = new TH1F ("h1","Histogram drawn with full circles",100,-4,4);
   auto h2 = new TH1F ("h2","Histogram drawn with full squares",100,-4,4);
   auto h3 = new TH1F ("h3","Histogram drawn with full triangles up",100,-4,4);
   auto h4 = new TH1F ("h4","Histogram drawn with full triangles down",100,-4,4);
   auto h5 = new TH1F ("h5","Histogram drawn with empty circles",100,-4,4);

   TRandom3 rng;
   Double_t px,py;
   for (Int_t i = 0; i < 25000; i++) {
      rng.Rannor(px,py);
      h1->Fill(px,10.);
      h2->Fill(px, 8.);
      h3->Fill(px, 6.);
      h4->Fill(px, 4.);
      h5->Fill(px, 2.);
   }

   h1->SetMarkerStyle(kFullCircle);
   h2->SetMarkerStyle(kFullSquare);
   h3->SetMarkerStyle(kFullTriangleUp);
   h4->SetMarkerStyle(kFullTriangleDown);
   h5->SetMarkerStyle(kOpenCircle);

   h1->Draw("PLC PMC");
   h2->Draw("SAME PLC PMC");
   h3->Draw("SAME PLC PMC");
   h4->Draw("SAME PLC PMC");
   h5->Draw("SAME PLC PMC");

   gPad->BuildLegend();
}