void DrawGraphWithLabelsOnPoints(TGraph *gr) {
   TExec *ex = new TExec("ex","DrawLabels();");
   gr->GetListOfFunctions()->Add(ex);
   gr->Draw("ALP");
   gr->GetXaxis()->SetLabelSize(0);
   gr->GetXaxis()->SetTickLength(0);
}


void DrawLabels()
{
   Int_t i,n;
   Double_t x,y;
   TLatex *t;
   TLine *tick;
   TLine *grid;

   TGraph *g = (TGraph*)gPad->GetListOfPrimitives()->FindObject("Graph");
   double ymin = g->GetHistogram()->GetMinimum();
   double ymax= g->GetHistogram()->GetMaximum();
   double dy = (ymax-ymin);
   n = g->GetN();
   for (i=0; i<n; i++) {
      g->GetPoint(i,x,y);
      t = new TLatex(x, ymin-0.03*dy, Form("%4.2f",x));
      t->SetTextSize(0.025);
      t->SetTextFont(42);
      t->SetTextAlign(21);
      t->Paint();
      tick = new TLine(x,ymin,x,ymin+0.03*dy);
      tick->Paint();
      grid = new TLine(x,ymin,x,y);
      grid->SetLineStyle(3);
      grid->Paint();
   }
}