{
   TCanvas *c1 = new TCanvas("c1", "c1",15,48,700,500);
	
   Double_t x[3] = {1, 2, 3};
   Double_t y[3] = {1, 1.5, 3};
   Double_t ex[3] = {0.5, 0.5, 0.5};

   TGraphErrors * ulGraph = new TGraphErrors(3, (Double_t*)(&x[0]), &y[0], &ex[0], 0);

   ulGraph->Draw("APEZ");
   ulGraph->GetYaxis()->SetRangeUser(0.0, 4.0);

   // Draw Arrows on UL points and ass x error bars
   ulGraph->SetMarkerStyle(9);
   TObjArray arrows;
   Double_t x1, y1, y2, yPad;
   gPad->Update();

   Double_t ymin = gPad->GetUymin();
   Double_t ymax = gPad->GetUymax();
   Double_t dy   = (0.075*(ymax-ymin))+ymin;

   for(Int_t j = 0; j<= ulGraph->GetN(); j++){
      ulGraph->GetPoint(j, x1, y1);
      y2 = y1-dy;
      arrows.Add(new TArrow(x1, y1, x1, y2, 0.015, "|>"));
      dynamic_cast<TArrow*>(arrows.Last())->Draw();
   }
}