void calbet4(){

   vector<string> v_file{"road60"};
   vector<string> v_var{"innerClosePrecHits", "middleClosePrecHits", "outerClosePrecHits", "extendedClosePrecHits"};
   vector<string> v_type{"non_iso", "hadron", "other", "prompt"};
   vector<string> v_pt{"3-5", "5-10", "10-20", "gt20"};
   vector<string> v_eta{"barrel", "endcap"};
   vector<int> v_color{kBlack, kBlue, kGreen, kRed};

   // hist
   const int n_file = v_file.size();
   const int n_var  = v_var .size();
   const int n_type = v_type.size();
   const int n_pt   = v_pt  .size();
   const int n_eta  = v_eta .size();

   TH1D *hist[n_file][n_type][n_pt][n_var];

   string name;

   for (int file=0; file<n_file; file++)
      for (int type=0; type<n_type; type++)
         for (int pt=0; pt<n_pt; pt++)
            for (int var=0; var<n_var; var++) {
               hist[file][type][pt][var] = new TH1D("", "", 20, 0, 30);
            }

   // variable to be read from tree
   int   innerClosePrecHits    (-99);
   int   middleClosePrecHits   (-99);
   int   outerClosePrecHits    (-99);
   int   extendedClosePrecHits (-99);
   int   TruthType             (-99);
   float pt                    (-99);

   for (int file=0; file<n_file; file++) {

      name = "MuonRates_ttbar_"+v_file[file]+".root";

      TFile *ifile = new TFile(name.c_str(), "READ");

      TTree *tree = (TTree*) ifile->Get("IDTracksTree");
      tree->SetBranchAddress("innerClosePrecHits"   , &innerClosePrecHits);
      tree->SetBranchAddress("middleClosePrecHits"  , &middleClosePrecHits);
      tree->SetBranchAddress("outerClosePrecHits"   , &outerClosePrecHits);
      tree->SetBranchAddress("extendedClosePrecHits", &extendedClosePrecHits);
      tree->SetBranchAddress("TruthType"            , &TruthType);
      tree->SetBranchAddress("pt"                   , &pt);

      int entries = tree->GetEntries();
      cout<<"entries: "<<entries<<endl;

      for (int i=0; i<entries; i++) {
         if (entries%1000==0) cout<<i<<" / "<<entries<<endl;
         tree->GetEntry(i);
         bool is_prompt {0};
         bool is_non_iso{0};
         bool is_hadron {0};
         bool is_other  {0};
         bool pt_3_5    {0};
         bool pt_5_10   {0};
         bool pt_10_20  {0};
         bool pt_gt20   {0};

         if      (TruthType==6)                  is_prompt  = true;
         else if (TruthType==7)                  is_non_iso = true;
         else if (TruthType==8 || TruthType==17) is_hadron  = true;
         else                                    is_other   = true;

         if      (pt>3  && pt<=5 ) pt_3_5   = true;
         else if (pt>5  && pt<=10) pt_5_10  = true;
         else if (pt>10 && pt<=20) pt_10_20 = true;
         else if (pt>20)           pt_gt20  = true;

         if (is_prompt) {
            if (pt_3_5) {
               if (innerClosePrecHits    != 0) hist[file][0][0][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][0][0][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][0][0][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][0][0][3]->Fill(extendedClosePrecHits);
            }
            if (pt_5_10) {
               if (innerClosePrecHits    != 0) hist[file][0][1][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][0][1][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][0][1][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][0][1][3]->Fill(extendedClosePrecHits);
            }
            if (pt_10_20) {
               if (innerClosePrecHits    != 0) hist[file][0][2][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][0][2][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][0][2][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][0][2][3]->Fill(extendedClosePrecHits);
            }
            if (pt_gt20) {
               if (innerClosePrecHits    != 0) hist[file][0][3][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][0][3][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][0][3][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][0][3][3]->Fill(extendedClosePrecHits);
            }
         } // is_prompt

         if (is_non_iso) {
            if (pt_3_5) {
               if (innerClosePrecHits    != 0) hist[file][1][0][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][1][0][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][1][0][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][1][0][3]->Fill(extendedClosePrecHits);
            }
            if (pt_5_10) {
               if (innerClosePrecHits    != 0) hist[file][1][1][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][1][1][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][1][1][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][1][1][3]->Fill(extendedClosePrecHits);
            }
            if (pt_10_20) {
               if (innerClosePrecHits    != 0) hist[file][1][2][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][1][2][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][1][2][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][1][2][3]->Fill(extendedClosePrecHits);
            }
            if (pt_gt20) {
               if (innerClosePrecHits    != 0) hist[file][1][3][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][1][3][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][1][3][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][1][3][3]->Fill(extendedClosePrecHits);
            }
         } // is_non_iso

         if (is_hadron) {
            if (pt_3_5) {
               if (innerClosePrecHits    != 0) hist[file][2][0][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][2][0][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][2][0][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][2][0][3]->Fill(extendedClosePrecHits);
            }
            if (pt_5_10) {
               if (innerClosePrecHits    != 0) hist[file][2][1][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][2][1][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][2][1][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][2][1][3]->Fill(extendedClosePrecHits);
            }
            if (pt_10_20) {
               if (innerClosePrecHits    != 0) hist[file][2][2][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][2][2][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][2][2][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][2][2][3]->Fill(extendedClosePrecHits);
            }
            if (pt_gt20) {
               if (innerClosePrecHits    != 0) hist[file][2][3][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][2][3][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][2][3][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][2][3][3]->Fill(extendedClosePrecHits);
            }
         } // is_hadron

         if (is_other) {
            if (pt_3_5) {
               if (innerClosePrecHits    != 0) hist[file][3][0][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][3][0][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][3][0][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][3][0][3]->Fill(extendedClosePrecHits);
            }
            if (pt_5_10) {
               if (innerClosePrecHits    != 0) hist[file][3][1][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][3][1][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][3][1][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][3][1][3]->Fill(extendedClosePrecHits);
            }
            if (pt_10_20) {
               if (innerClosePrecHits    != 0) hist[file][3][2][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][3][2][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][3][2][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][3][2][3]->Fill(extendedClosePrecHits);
            }
            if (pt_gt20) {
               if (innerClosePrecHits    != 0) hist[file][3][3][0]->Fill(innerClosePrecHits);
               if (middleClosePrecHits   != 0) hist[file][3][3][1]->Fill(middleClosePrecHits);
               if (outerClosePrecHits    != 0) hist[file][3][3][2]->Fill(outerClosePrecHits);
               if (extendedClosePrecHits != 0) hist[file][3][3][3]->Fill(extendedClosePrecHits);
            }
         } // is_other
      } // entries
   } // files

   auto C = new TCanvas("C","C",600,400);

   double integral;

   for (int var=0; var<1; var++) {
      for (int pt=0; pt<n_pt; pt++) {
         for (int file=0; file<n_file; file++) {

            TH1D *hist_prompt = (TH1D*)hist[file][0][pt][var]->Clone();
            integral = hist_prompt->Integral(); if (integral != 0) hist_prompt->Scale(1/integral);
            hist_prompt->SetLineWidth(2); hist_prompt->SetLineColor(kRed);

            TH1D *hist_fake_noniso = (TH1D*)hist[file][1][pt][var]->Clone();

            integral = hist_fake_noniso->Integral(); if (integral != 0) hist_fake_noniso->Scale(1/integral);

            hist_fake_noniso->SetLineWidth(2); hist_fake_noniso->SetLineColor(kBlue);

            auto ratio_noniso = new TRatioPlot(hist_prompt, hist_fake_noniso);

            ratio_noniso -> SetH2DrawOpt("hist");
            ratio_noniso -> Draw(); // draw 1st to access primitive!!
            ratio_noniso -> GetLowerRefGraph() -> SetMinimum(0.);
            ratio_noniso -> GetLowerRefGraph() -> SetMaximum(1.5);
         } // pt
      } // file
   } // var
}