void test() {
  // adapted from $ROOTSYS/tutorials/graphs/gerrors.C by Rene Brun
  
  TCanvas *c1 = new TCanvas("c1","A Simple Graph with error bars",200,10,700,500);
    c1->SetFillColor(42);
  c1->SetGrid();
  c1->GetFrame()->SetFillColor(21);
  c1->GetFrame()->SetBorderSize(12);
  c1->SetBottomMargin(0.15);
  
  const Int_t n = 10;
  Float_t x[n]  = {-0.22, 0.05, 0.25, 0.35, 0.5, 0.61,0.7,0.85,0.89,0.95};
  Float_t y[n]  = {1,2.9,5.6,7.4,9,9.6,8.7,6.3,4.5,1};
  Float_t ex[n] = {.05,.1,.07,.07,.04,.05,.06,.07,.08,.05};
  Float_t ey[n] = {.8,.7,.6,.5,.4,.4,.5,.6,.7,.8};
  TGraphErrors *gr = new TGraphErrors(n,x,y,ex,ey);
  gr->SetTitle("TGraphErrors Example");
  gr->SetMarkerColor(4);
  gr->SetMarkerStyle(21);
  gr->Draw("ALP");

  float xmin = gr->GetXaxis()->GetXmin();
  float xmax = gr->GetXaxis()->GetXmax();

  const short nBins	= 4;
  float xBins[nBins+1]	= { xmin, -0.15, 0.42, 0.8, xmax };
  TString labels[]	= { "iD0", "iD1", "iD2", "iD3" };

  TH1F *h = new TH1F("h","dummy", nBins, xBins);
  for(short bin = 1; bin < nBins+1 ; bin++ ){
    h->SetBinContent( bin, bin*0.9 );
    h->GetXaxis()->SetBinLabel( bin , labels[bin-1] );
  }
  h->SetStats(kFALSE);
  h->Draw("SAMES");
  
  TGaxis *ax = new TGaxis(xmin, -1.5, xmax, -1.5, 0, 2, 0, "");
  ax->ImportAxisAttributes( h->GetXaxis() );
  ax->Draw();

  c1->Update();
}