graph

Draw a simple graph.

Author: Rene Brun
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Sunday, October 02, 2022 at 09:31 AM.

In [1]:
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");
 i 0 0.000000 1.986693 
 i 1 0.100000 2.955202 
 i 2 0.200000 3.894183 
 i 3 0.300000 4.794255 
 i 4 0.400000 5.646425 
 i 5 0.500000 6.442177 
 i 6 0.600000 7.173561 
 i 7 0.700000 7.833269 
 i 8 0.800000 8.414710 
 i 9 0.900000 8.912074 
 i 10 1.000000 9.320391 
 i 11 1.100000 9.635582 
 i 12 1.200000 9.854497 
 i 13 1.300000 9.974950 
 i 14 1.400000 9.995736 
 i 15 1.500000 9.916648 
 i 16 1.600000 9.738476 
 i 17 1.700000 9.463001 
 i 18 1.800000 9.092974 
 i 19 1.900000 8.632094 

TCanvas::Update() draws the frame, after which one can change it

In [2]:
c1->Update();
c1->GetFrame()->SetBorderSize(12);
c1->Modified();

Draw all canvases

In [3]:
gROOT->GetListOfCanvases()->Draw()