PatBasicFWLiteAnalyzer.cc

Go to the documentation of this file.

#include <memory>
#include <string>
#include <vector>
#include <sstream>
#include <fstream>
#include <iostream>
 
#include <TH1F.h>
#include <TROOT.h>
#include <TFile.h>
#include <TSystem.h>
 
#include "DataFormats/FWLite/interface/Event.h"
#include "DataFormats/Common/interface/Handle.h"
#include "FWCore/FWLite/interface/FWLiteEnabler.h"
 
#include "DataFormats/FWLite/interface/InputSource.h"
#include "DataFormats/FWLite/interface/OutputFiles.h"
#include "FWCore/ParameterSet/interface/ParameterSet.h"
#include "FWCore/ParameterSetReader/interface/ParameterSetReader.h"
 
#include "DataFormats/PatCandidates/interface/Muon.h"
#include "PhysicsTools/FWLite/interface/TFileService.h"
 
int main(int argc, char* argv[]) {
  // ----------------------------------------------------------------------
  // First Part:
  //
  //  * enable FWLite
  //  * book the histograms of interest
  //  * open the input file
  // ----------------------------------------------------------------------
 
  // load framework libraries
  gSystem->Load("libFWCoreFWLite");
  FWLiteEnabler::enable();
 
  // only allow one argument for this simple example which should be the
  // the python cfg file
  if (argc < 2) {
    std::cout << "Usage : " << argv[0] << " [parameters.py]" << std::endl;
    return 0;
  }
  if (!edm::readPSetsFrom(argv[1])->existsAs<edm::ParameterSet>("process")) {
    std::cout << " ERROR: ParametersSet 'process' is missing in your configuration file" << std::endl;
    exit(0);
  }
  // get the python configuration
  const edm::ParameterSet& process = edm::readPSetsFrom(argv[1])->getParameter<edm::ParameterSet>("process");
  fwlite::InputSource inputHandler_(process);
  fwlite::OutputFiles outputHandler_(process);
 
  // now get each parameter
  const edm::ParameterSet& ana = process.getParameter<edm::ParameterSet>("muonAnalyzer");
  edm::InputTag muons_(ana.getParameter<edm::InputTag>("muons"));
 
  // book a set of histograms
  fwlite::TFileService fs = fwlite::TFileService(outputHandler_.file());
  TFileDirectory dir = fs.mkdir("analyzeBasicPat");
  TH1F* muonPt_ = dir.make<TH1F>("muonPt", "pt", 100, 0., 300.);
  TH1F* muonEta_ = dir.make<TH1F>("muonEta", "eta", 100, -3., 3.);
  TH1F* muonPhi_ = dir.make<TH1F>("muonPhi", "phi", 100, -5., 5.);
 
  // loop the events
  int ievt = 0;
  int maxEvents_(inputHandler_.maxEvents());
  for (unsigned int iFile = 0; iFile < inputHandler_.files().size(); ++iFile) {
    // open input file (can be located on castor)
    TFile* inFile = TFile::Open(inputHandler_.files()[iFile].c_str());
    if (inFile) {
      // ----------------------------------------------------------------------
      // Second Part:
      //
      //  * loop the events in the input file
      //  * receive the collections of interest via fwlite::Handle
      //  * fill the histograms
      //  * after the loop close the input file
      // ----------------------------------------------------------------------
      fwlite::Event ev(inFile);
      for (ev.toBegin(); !ev.atEnd(); ++ev, ++ievt) {
        edm::EventBase const& event = ev;
        // break loop if maximal number of events is reached
        if (maxEvents_ > 0 ? ievt + 1 > maxEvents_ : false)
          break;
        // simple event counter
        if (inputHandler_.reportAfter() != 0 ? (ievt > 0 && ievt % inputHandler_.reportAfter() == 0) : false)
          std::cout << "  processing event: " << ievt << std::endl;
 
        // Handle to the muon collection
        edm::Handle<std::vector<pat::Muon> > muons;
        event.getByLabel(muons_, muons);
 
        // loop muon collection and fill histograms
        for (unsigned i = 0; i < muons->size(); ++i) {
          muonPt_->Fill((*muons)[i].pt());
          muonEta_->Fill((*muons)[i].eta());
          muonPhi_->Fill((*muons)[i].phi());
        }
      }
      // close input file
      inFile->Close();
    }
    // break loop if maximal number of events is reached:
    // this has to be done twice to stop the file loop as well
    if (maxEvents_ > 0 ? ievt + 1 > maxEvents_ : false)
      break;
  }
  return 0;
}