TopElecFWLiteAnalyzer.cc

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#include <memory>
#include <string>
#include <cstdlib>
#include <sstream>
#include <fstream>
#include <iostream>
 
#include "FWCore/FWLite/interface/FWLiteEnabler.h"
#include "DataFormats/PatCandidates/interface/Electron.h"
 
#include "TopQuarkAnalysis/Examples/bin/NiceStyle.cc"
#include "TopQuarkAnalysis/Examples/interface/RootSystem.h"
#include "TopQuarkAnalysis/Examples/interface/RootHistograms.h"
#include "TopQuarkAnalysis/Examples/interface/RootPostScript.h"
 
int main(int argc, char* argv[]) {
  if (argc < 3) {
    // -------------------------------------------------
    std::cerr << "ERROR:: "
              << "Wrong number of arguments! Please specify:" << std::endl
              << "        * filepath" << std::endl
              << "        * process name" << std::endl;
    // -------------------------------------------------
    return -1;
  }
 
  // load framework libraries
  gSystem->Load("libFWCoreFWLite");
  FWLiteEnabler::enable();
 
  // set nice style for histograms
  setNiceStyle();
 
  // define some histograms
  TH1I* noElecs = new TH1I("noElecs", "N_{Elecs}", 10, 0, 10);
  TH1F* ptElecs = new TH1F("ptElecs", "pt_{Elecs}", 100, 0., 300.);
  TH1F* enElecs = new TH1F("enElecs", "energy_{Elecs}", 100, 0., 300.);
  TH1F* etaElecs = new TH1F("etaElecs", "eta_{Elecs}", 100, -3., 3.);
  TH1F* phiElecs = new TH1F("phiElecs", "phi_{Elecs}", 100, -5., 5.);
 
  // -------------------------------------------------
  std::cout << "open  file: " << argv[1] << std::endl;
  // -------------------------------------------------
  TFile* inFile = TFile::Open(argv[1]);
  TTree* events_ = nullptr;
  if (inFile)
    inFile->GetObject("Events", events_);
  if (events_ == nullptr) {
    // -------------------------------------------------
    std::cerr << "ERROR:: "
              << "Unable to retrieve TTree Events!" << std::endl
              << "        Eighter wrong file name or the the tree doesn't exists" << std::endl;
    // -------------------------------------------------
    return -1;
  }
 
  // acess branch of elecs
  char elecName[50];
  sprintf(elecName, "patElectrons_selectedPatElectrons__%s.obj", argv[2]);
  TBranch* elecs_ = events_->GetBranch(elecName);
  assert(elecs_ != nullptr);
 
  // loop over events and fill histograms
  std::vector<pat::Electron> elecs;
  int nevt = events_->GetEntries();
 
  // -------------------------------------------------
  std::cout << "start looping " << nevt << " events..." << std::endl;
  // -------------------------------------------------
  for (int evt = 0; evt < nevt; ++evt) {
    // set branch address
    elecs_->SetAddress(&elecs);
    // get event
    elecs_->GetEntry(evt);
    events_->GetEntry(evt, 0);
 
    // -------------------------------------------------
    if (evt > 0 && !(evt % 10))
      std::cout << "  processing event: " << evt << std::endl;
    // -------------------------------------------------
 
    // fill histograms
    noElecs->Fill(elecs.size());
    for (unsigned idx = 0; idx < elecs.size(); ++idx) {
      // fill histograms
      ptElecs->Fill(elecs[idx].pt());
      enElecs->Fill(elecs[idx].energy());
      etaElecs->Fill(elecs[idx].eta());
      phiElecs->Fill(elecs[idx].phi());
    }
  }
  // -------------------------------------------------
  std::cout << "close file" << std::endl;
  // -------------------------------------------------
  inFile->Close();
 
  // save histograms to file
  TFile outFile("analyzeElecs.root", "recreate");
  outFile.mkdir("analyzeElec");
  outFile.cd("analyzeElec");
  noElecs->Write();
  ptElecs->Write();
  enElecs->Write();
  etaElecs->Write();
  phiElecs->Write();
  outFile.Close();
 
  // free allocated space
  delete noElecs;
  delete ptElecs;
  delete enElecs;
  delete etaElecs;
  delete phiElecs;
 
  return 0;
}