ForestErrAnal Lab7 Plot.C

void graph() {

  TCanvas *c1 = new TCanvas("c1","A Simple Graph Example",200,10,700,500);
  const Int_t n = 3;
  Double_t x[n], y[n];

  x[0]=1;
  y[0]=2;
  x[1]=2;
  y[1]=4;
  x[2]=6;
  y[2]=12;
  x[3]=10;
  y[3]=20;

  TGraph *gr = new TGraph(n,x,y);
  gr->Draw("ACL");


   c1->SetFillColor(42);
   c1->SetGrid();

   // TCanvas::Update() draws the frame, after which one can change it             
   c1->Update();
   c1->Modified();
}