void FitTest() {

  TList* l = new TList;

  for (Int_t i = 0; i < 10; i++) {
    TH1D* h = new TH1D(Form("h%02d", i), Form("Histogram %02d", i), 20, -5., 5.);
    h->FillRandom("gaus");
    l->Add(h);
  }

  TCanvas* c = new TCanvas;

  TListIter nextHist(l);
  TH1D* h;
  while ((h = (TH1D*) nextHist())) {

    c->cd();
    h->Draw();
    c->Update();

    cout << "Do you want to fit this histogram [y/n]? " << flush;
    TString input;
    cin >> input;
    input.ToLower();
    if (!input.BeginsWith("y"))
      continue;

    TF1* f1 = new TF1("user", "gaus", -5., 5.);

    h->FitPanel();

    TList *lc = (TList*)gROOT->GetListOfCanvases();
    TFitPanel *fitPanel = (TFitPanel*) lc->FindObject("R__fitpanel");
    gClient->WaitFor((TGWindow*) fitPanel->GetCanvasImp());

    // After this I would typically store the fitted function.
  }
}