inclusive_detached_dilepton/basic_analysis.h

#ifndef BASIC_ANALYSIS
#define BASIC_ANALYSIS

#include <string>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <filesystem>
#include <string_view>

#include "TTree.h"

class FourVect
{
private:
  Float_t px, py, pz, energy;

  Float_t *PtrPX()
  {
    return &px;
  }

  Float_t *PtrPY()
  {
    return &py;
  }

  Float_t *PtrPZ()
  {
    return &pz;
  }

  Float_t *PtrEnergy()
  {
    return &energy;
  }

public:
  static FourVect *Init(TTree *tree, const char *particle)
  {
    FourVect *v = new FourVect{};
    tree->SetBranchAddress(TString::Format("%s_PX", particle).Data(), v->PtrPX());
    tree->SetBranchAddress(TString::Format("%s_PY", particle).Data(), v->PtrPY());
    tree->SetBranchAddress(TString::Format("%s_PZ", particle).Data(), v->PtrPZ());
    tree->SetBranchAddress(TString::Format("%s_ENERGY", particle).Data(), v->PtrEnergy());
    return v;
  }

  TLorentzVector LorentzVector()
  {
    return TLorentzVector(px, py, pz, energy);
  }

  TLorentzVector LorentzVector(double sub_mass)
  {
    TVector3 momentum(px, py, pz);
    float energy = TMath::Sqrt(TMath::Sq(sub_mass) + momentum.Mag2());
    return TLorentzVector(momentum, energy);
  }

  std::string ToString()
  {
    return TString::Format("(%f, %f, %f, %f)", px, py, pz, energy).Data();
  }
};

void DrawInDefaultCanvas(TH1 *histogram, const char *folder, double margin_left = 0, Option_t *option = "")
{
  std::filesystem::create_directory(TString::Format("output_files/analysis/%s", folder).Data());
  TString name = TString::Format("%s_canvas", histogram->GetName());
  TCanvas *c = new TCanvas(name, histogram->GetName(), 0, 0, 800, 600);
  c->SetLeftMargin(margin_left);
  histogram->SetStats(0);
  histogram->Draw(option);
  c->Draw();
  c->SaveAs(TString::Format("output_files/analysis/%s/%s.pdf", folder, name.Data()).Data());
}

void DrawInDefaultCanvas(RooPlot *rooPlot, const char *folder, double margin_left = 0, Option_t *option = "")
{
  std::filesystem::create_directory(TString::Format("output_files/analysis/%s", folder).Data());
  TString name = TString::Format("%s_canvas", rooPlot->GetName());
  TCanvas *c = new TCanvas(name, rooPlot->GetName(), 0, 0, 800, 600);
  c->SetLeftMargin(margin_left);
  rooPlot->Draw(option);
  c->Draw();
  c->SaveAs(TString::Format("output_files/analysis/%s/%s.pdf", folder, name.Data()).Data());
}

void PrintProgress(const char *title, unsigned int total, unsigned int every, unsigned int current)
{
  if ((current + 1) % every == 0 || current + 1 == total)
  {
    std::cout << "["
              << title
              << "] Processed event: " << current + 1 << " (" << TString::Format("%.2f", ((double)(current + 1) / (double)total) * 100.) << "%)" << std::endl;
  }
}

RooPlot *CreateRooFitHistogram(TH1D *hist)
{
  RooRealVar roo_var_mass("var_mass", "B Mass Variable", B_MASS_VAR_MIN, B_MASS_VAR_MAX);
  roo_var_mass.setRange("fitting_range", B_MASS_VAR_MIN, B_MASS_VAR_MAX);

  RooDataHist roohist_B_M("roohist_B_M", "B Mass Histogram", roo_var_mass, RooFit::Import(*hist));

  RooPlot *roo_frame_mass = roo_var_mass.frame(RooFit::Title(hist->GetTitle()), RooFit::Name(TString::Format("%s_rplt", hist->GetName())));
  roohist_B_M.plotOn(roo_frame_mass, RooFit::Binning(B_MASS_HIST_BINS), RooFit::Name("B Mass Distribution"));
  roo_frame_mass->GetXaxis()->SetTitle(hist->GetXaxis()->GetTitle());

  return roo_frame_mass;
}

struct ShapeParamters
{
  double alpha_left;
  double n_left;
  double alpha_right;
  double n_right;
};

struct RooFitSummary
{
  RooPlot *fit_histogram;
  RooPlot *pull_histogram;
  ShapeParamters shape_parameters;
};

RooFitSummary CreateRooFitHistogramAndFitCB(TH1D *hist, bool hasExpBkg, bool useExtShape, ShapeParamters extShape)
{
  auto suffix_name = [name = hist->GetName()](const char *text)
  {
    return TString::Format("%s_%s", text, name);
  };

  RooRealVar roo_var_mass(suffix_name("var_mass"), "B Mass Variable", B_MASS_VAR_MIN, B_MASS_VAR_MAX);
  const char *fitting_range_name = "fitting_range";
  roo_var_mass.setRange(fitting_range_name, B_MASS_VAR_MIN, B_MASS_VAR_MAX);

  TString hist_name = suffix_name("roohist_B_M");
  RooDataHist roohist_B_M(hist_name, "B Mass Histogram", roo_var_mass, RooFit::Import(*hist));

  RooPlot *roo_frame_mass = roo_var_mass.frame(RooFit::Title(hist->GetTitle()), RooFit::Name(TString::Format("%s_rplt", hist->GetName())));
  roohist_B_M.plotOn(roo_frame_mass, RooFit::Binning(B_MASS_HIST_BINS), RooFit::Name(hist_name));
  roo_frame_mass->GetXaxis()->SetTitle(hist->GetXaxis()->GetTitle());

  // Crystal Ball for Signal
  RooRealVar var_mass_x0(suffix_name("var_mass_x0"), "#mu", 5278., 5170., 5500.);
  RooRealVar var_mass_sigmaLR(suffix_name("var_mass_sigmaLR"), "#sigma_{LR}", 16., 5., 40.);

  RooRealVar var_mass_alphaL(suffix_name("var_mass_alphaL"), "#alpha_{L}", 2., 0., 4.);
  RooRealVar var_mass_nL(suffix_name("var_mass_nL"), "n_{L}", 5., 0., 15.);
  RooRealVar var_mass_alphaR(suffix_name("var_mass_alphaR"), "#alpha_{R}", 2., 0., 4.);
  RooRealVar var_mass_nR(suffix_name("var_mass_nR"), "n_{R}", 5., 0., 15.);

  if (useExtShape) {
    var_mass_alphaL.setConstant(true);
    var_mass_alphaL.setVal(extShape.alpha_left);

    var_mass_nL.setConstant(true);
    var_mass_nL.setVal(extShape.n_left);

    var_mass_alphaR.setConstant(true);
    var_mass_alphaR.setVal(extShape.alpha_right);

    var_mass_nR.setConstant(true);
    var_mass_nR.setVal(extShape.n_left);
  }

  TString signal_name = suffix_name("sig_cb");
  RooCrystalBall sig_cb(signal_name, "Signal Crystal Ball", roo_var_mass, var_mass_x0, var_mass_sigmaLR, var_mass_alphaL, var_mass_nL, var_mass_alphaR, var_mass_nR);

  TString pull_compare_name{};
  if (hasExpBkg)
  {
    // Exponential for Background
    RooRealVar var_mass_bkg_c(suffix_name("var_mass_bkg_c"), "#lambda", -0.0014, -0.004, -0.000);

    TString background_name = suffix_name("bgk_exp");
    RooExponential bkg_exp(background_name, "Exp Background", roo_var_mass, var_mass_bkg_c);

    RooRealVar var_mass_nsig(suffix_name("nsig"), "N_{Sig}", 0., hist->GetEntries());
    RooRealVar var_mass_nbkg(suffix_name("nbkg"), "N_{Bkg}", 0., hist->GetEntries());

    TString fitted_pdf_name = suffix_name("sigplusbkg");
    RooAddPdf fitted_pdf(fitted_pdf_name, "Sig and Bkg PDF", RooArgList(sig_cb, bkg_exp), RooArgList(var_mass_nsig, var_mass_nbkg));

    RooFitResult *fitres = fitted_pdf.fitTo(roohist_B_M, RooFit::Save(), RooFit::PrintLevel(1), RooFit::Range(fitting_range_name));

    // sigplusbkg.plotOn(roo_frame_mass, RooFit::VisualizeError(*fitres, 1), RooFit::FillColor(kOrange + 1), RooFit::FillStyle(3144));
    fitted_pdf.plotOn(roo_frame_mass, RooFit::LineColor(kRed), RooFit::LineStyle(kSolid), RooFit::Range(fitting_range_name), RooFit::Name(fitted_pdf_name));
    fitted_pdf.plotOn(roo_frame_mass, RooFit::Components(RooArgSet(bkg_exp)), RooFit::LineColor(kBlue - 7), RooFit::LineStyle(kDashed), RooFit::Range(fitting_range_name), RooFit::Name(background_name));
    fitted_pdf.plotOn(roo_frame_mass, RooFit::Components(RooArgSet(sig_cb)), RooFit::LineColor(kRed - 7), RooFit::LineStyle(kDashed), RooFit::Range(fitting_range_name), RooFit::Name(signal_name));
    fitted_pdf.paramOn(roo_frame_mass);

    pull_compare_name = fitted_pdf_name;
  }
  else
  {
    RooFitResult *fitres = sig_cb.fitTo(roohist_B_M, RooFit::Save(), RooFit::PrintLevel(1), RooFit::Range(fitting_range_name));

    // sigplusbkg.plotOn(roo_frame_mass, RooFit::VisualizeError(*fitres, 1), RooFit::FillColor(kOrange + 1), RooFit::FillStyle(3144));
    sig_cb.plotOn(roo_frame_mass, RooFit::LineColor(kRed), RooFit::LineStyle(kSolid), RooFit::Range(fitting_range_name), RooFit::Name(signal_name));
    pull_compare_name = signal_name;
    sig_cb.paramOn(roo_frame_mass);
  }

  RooPlot *roo_frame_pull = roo_var_mass.frame(RooFit::Title("Pull Distribution"), RooFit::Name(TString::Format("%s_pull_rplt", hist->GetName())));
  roo_frame_pull->addPlotable(roo_frame_mass->pullHist(hist_name, pull_compare_name), "P");

  return RooFitSummary{
      roo_frame_mass,
      roo_frame_pull,
      ShapeParamters{
          var_mass_alphaL.getVal(),
          var_mass_nL.getVal(),
          var_mass_alphaR.getVal(),
          var_mass_nR.getVal()}};
}

bool InRange(double value, double center, double low_intvl, double up_intvl)
{
  return center - low_intvl < value && value < center + up_intvl;
}

bool InRange(double value, double center, double intvl)
{
  return InRange(value, center, intvl, intvl);
}

#endif