using namespace RooFit;

void variable_bin_test(){

  TRandom3 rndgen;

  std::vector<Double_t> edges_bins{ 300, 347, 395, 443, 491, 540, 589, 639, 689, 740, 791, 843, 895, 948,1002, 1056, 1111, 1167, 1224, 1281, 1339, 1398, 1458, 1519, 1581, 1644,1708, 1773, 1839, 1906, 1974, 2043, 2114, 2186, 2259, 2333, 2409, 2486,2564, 2644, 2725, 2808, 2892, 2978, 3065, 3154, 3244, 3336, 3430,3526, 3623, 3722, 3823, 3926, 4031, 4138, 4247, 4358, 4472, 4588,4706, 4826, 4949, 5074};
  Double_t* edges = &edges_bins[0];
  Int_t NBINS = edges_bins.size()-1;
  TH1* h = new TH1D("h","Hist with variable bin width",NBINS,edges);
  for (Int_t i=0; i<82225; i++){
    h->Fill(rndgen.Gaus(2500.,400.));
   }

  //h->Scale(1./h->Integral());

  RooRealVar mjj("mjj","mjj", 300, 5074);
  RooBinning mjjbin(NBINS, edges, "mjjbin");
  //RooWorkspace w();
  mjj.setBinning(mjjbin);
  RooDataHist hdata("hdata","hdata", mjj, h);

  mjj.setBins(NBINS);
  RooHistPdf pdf("pdf","pdf",mjj,hdata);
  mjj.setBins(NBINS);
    
  auto c = new TCanvas("c","c");
  gPad->SetLogy();
  h->SetLineStyle(2);
  h->GetYaxis()->SetTitle("Arbitrary units");
  h->GetXaxis()->SetTitle("m_{JJ} [GeV]");
  h->Draw("Hist");

  RooPlot *frameData = mjj.frame(Bins(NBINS));
  hdata.plotOn(frameData, Name("hdata"), LineColor(kRed), LineStyle(kDashed), DrawOption("HIST"));
  pdf.plotOn(frameData, Name("pdf"), LineColor(kBlue), LineStyle(kDashed));
  frameData->Draw("hist same");

  auto legend = new TLegend(0.65, 0.75, 0.95, 0.9);
  legend->SetBorderSize(0);
  legend->AddEntry(h, "Original histogram","l");
  legend->AddEntry("hdata", "RooDataHist","l");
  legend->AddEntry("pdf", "RooHistPdf","l");
  legend->Draw();

  

}