gStyle->SetOptStat(0);
auto c1 = new TCanvas("c1", "fit residual simple");
gPad->SetFrameFillStyle(0);
auto h1 = new TH1D("h1", "h1", 50, -5, 5);
h1->FillRandom("gaus", 5000);
TFitResultPtr fitres = h1->Fit("gaus", "S0");
h1->Sumw2();
h1->GetXaxis()->SetTitle("x");
h1->GetYaxis()->SetTitle("y");
auto rp1 = new TRatioPlot(h1, "errfunc");
rp1->SetGraphDrawOpt("L");
rp1->SetSeparationMargin(0.0);
rp1->Draw();
rp1->GetLowerRefGraph()->SetMinimum(-2);
rp1->GetLowerRefGraph()->SetMaximum(2);

gROOT->GetListOfCanvases()->Draw()