gStyle->SetOptStat(0);
auto c1 = new TCanvas("c1", "fit residual simple");
auto h1 = new TH1D("h1", "h1", 50, -5, 5);
h1->FillRandom("gaus", 2000);
h1->Fit("gaus", "0");
h1->GetXaxis()->SetTitle("x");
h1->GetYaxis()->SetTitle("y");
auto rp1 = new TRatioPlot(h1);
std::vector<double> lines = {-3, -2, -1, 0, 1, 2, 3};
rp1->SetGridlines(lines);
rp1->Draw();
rp1->GetLowerRefGraph()->SetMinimum(-4);
rp1->GetLowerRefGraph()->SetMaximum(4);

gROOT->GetListOfCanvases()->Draw()