graph.C

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/// \file
/// \ingroup tutorial_graphs
/// \notebook
/// Draw a simple graph.
///
/// \macro_image
/// \macro_code
///
/// \author Rene Brun
 
void graph()
{
   TCanvas *c1 = new TCanvas("c1", "A Simple Graph Example", 200, 10, 700, 500);
 
   c1->SetGrid();
 
   const Int_t n = 20;
   Double_t x[n], y[n];
   for (Int_t i = 0; i < n; i++) {
      x[i] = i * 0.1;
      y[i] = 10 * sin(x[i] + 0.2);
      printf(" i %i %f %f \n", i, x[i], y[i]);
   }
   TGraph *gr = new TGraph(n, x, y);
   gr->SetLineColor(2);
   gr->SetLineWidth(4);
   gr->SetMarkerColor(4);
   gr->SetMarkerStyle(21);
   gr->SetTitle("a simple graph");
   gr->GetXaxis()->SetTitle("X title");
   gr->GetYaxis()->SetTitle("Y title");
   gr->Draw("ACP");
 
   // TCanvas::Update() draws the frame, after which one can change it
   c1->Update();
   c1->GetFrame()->SetBorderSize(12);
   c1->Modified();
}