{

   gROOT->Reset();
 
   /*** create the canvas ***/
   c1 = new TCanvas("c1","Title", 200, 10, 700, 500);

   /* 
      if omitted, canvas c1 is created automatically 
   */

   /*** create the data ***/

   float x[3], y[3];

   x[0] = 1.; 
   x[1] = 2.; 
   x[2] = 3.; 

   y[0] = 1.;
   y[1] = 2.;
   y[2] = 3.;

   /*** create the graph ***/
   graph = new TGraph(3, x, y);

   /*** draw it ***/
   graph->Draw("AP");

   c1->Update(); // necessary for axis titles!

   graph->GetHistogram()->SetXTitle("x axis");
   graph->GetHistogram()->SetYTitle("y axis");
    
}