#include <ShiftedPFCandidateProducerForNoPileUpPFMEt.h>

Inheritance diagram for ShiftedPFCandidateProducerForNoPileUpPFMEt:

Public Member Functions
	ShiftedPFCandidateProducerForNoPileUpPFMEt (const edm::ParameterSet &)
	~ShiftedPFCandidateProducerForNoPileUpPFMEt ()
Private Member Functions
void	produce (edm::Event &, const edm::EventSetup &)
Private Attributes
JetCorrectionUncertainty *	jecUncertainty_
edm::FileInPath	jetCorrInputFileName_
JetCorrectorParameters *	jetCorrParameters_
std::string	jetCorrPayloadName_
std::string	jetCorrUncertaintyTag_
double	minJetPt_
std::string	moduleLabel_
double	shiftBy_
edm::InputTag	srcJets_
edm::InputTag	srcPFCandidates_
double	unclEnUncertainty_

Detailed Description

Vary energy of PFCandidates which are (are not) within jets of Pt > 10 GeV by jet energy uncertainty (by 10% "unclustered" energy uncertainty)

NOTE: Auxiliary class specific to estimating systematic uncertainty on PFMET reconstructed by no-PU MET reconstruction algorithm (implemented in JetMETCorrections/Type1MET/src/NoPileUpPFMETProducer.cc)

In case all PFCandidates not within jets of Pt > 30 GeV would be varied by the 10% "unclustered" energy uncertainty, the systematic uncertainty on the reconstructed no-PU MET would be overestimated significantly !!

Author:: Christian Veelken, LLR

Version:

Revision:: 1.1

Id:: ShiftedPFCandidateProducerForNoPileUpPFMEt.h,v 1.1 2012/08/31 10:06:13 veelken Exp

Definition at line 40 of file ShiftedPFCandidateProducerForNoPileUpPFMEt.h.

Constructor & Destructor Documentation

ShiftedPFCandidateProducerForNoPileUpPFMEt::ShiftedPFCandidateProducerForNoPileUpPFMEt ( const edm::ParameterSet & cfg ) [explicit]

Definition at line 14 of file ShiftedPFCandidateProducerForNoPileUpPFMEt.cc.

References gather_cfg::cout, edm::ParameterSet::exists(), edm::FileInPath::fullPath(), edm::ParameterSet::getParameter(), edm::FileInPath::isLocal(), jecUncertainty_, jetCorrInputFileName_, jetCorrParameters_, jetCorrPayloadName_, jetCorrUncertaintyTag_, minJetPt_, shiftBy_, srcJets_, srcPFCandidates_, and unclEnUncertainty_.

  : moduleLabel_(cfg.getParameter<std::string>("@module_label"))
{
  srcPFCandidates_ = cfg.getParameter<edm::InputTag>("srcPFCandidates");
  srcJets_ = cfg.getParameter<edm::InputTag>("srcJets");

  jetCorrUncertaintyTag_ = cfg.getParameter<std::string>("jetCorrUncertaintyTag");
  if ( cfg.exists("jetCorrInputFileName") ) {
    jetCorrInputFileName_ = cfg.getParameter<edm::FileInPath>("jetCorrInputFileName");
    if ( !jetCorrInputFileName_.isLocal()) throw cms::Exception("ShiftedJetProducerT") 
      << " Failed to find JEC parameter file = " << jetCorrInputFileName_ << " !!\n";
    std::cout << "Reading JEC parameters = " << jetCorrUncertaintyTag_  
              << " from file = " << jetCorrInputFileName_.fullPath() << "." << std::endl;
    jetCorrParameters_ = new JetCorrectorParameters(jetCorrInputFileName_.fullPath().data(), jetCorrUncertaintyTag_);
    jecUncertainty_ = new JetCorrectionUncertainty(*jetCorrParameters_);
  } else {
    std::cout << "Reading JEC parameters = " << jetCorrUncertaintyTag_
              << " from DB/SQLlite file." << std::endl;
    jetCorrPayloadName_ = cfg.getParameter<std::string>("jetCorrPayloadName");
  }

  minJetPt_ = cfg.getParameter<double>("minJetPt");

  shiftBy_ = cfg.getParameter<double>("shiftBy");
  
  unclEnUncertainty_ = cfg.getParameter<double>("unclEnUncertainty");

  produces<reco::PFCandidateCollection>();
}

ShiftedPFCandidateProducerForNoPileUpPFMEt::~ShiftedPFCandidateProducerForNoPileUpPFMEt ( )

Definition at line 44 of file ShiftedPFCandidateProducerForNoPileUpPFMEt.cc.

{
// nothing to be done yet...
}

Member Function Documentation

void ShiftedPFCandidateProducerForNoPileUpPFMEt::produce	(	edm::Event &	evt,
		const edm::EventSetup &	es
	)		`[private, virtual]`

Implements edm::EDProducer.

Definition at line 49 of file ShiftedPFCandidateProducerForNoPileUpPFMEt.cc.

References deltaR(), alignCSCRings::e, reco::LeafCandidate::eta(), edm::EventSetup::get(), edm::Event::getByLabel(), reco::PFJet::getPFConstituents(), JetCorrectionUncertainty::getUncertainty(), jecUncertainty_, metsig::jet, jetCorrPayloadName_, jetCorrUncertaintyTag_, fwrapper::jets, minJetPt_, reco::LeafCandidate::pt(), edm::Event::put(), JetCorrectionUncertainty::setJetEta(), JetCorrectionUncertainty::setJetPt(), reco::LeafCandidate::setP4(), edm::shift, srcJets_, srcPFCandidates_, and unclEnUncertainty_.

{
  edm::Handle<reco::PFCandidateCollection> originalPFCandidates;
  evt.getByLabel(srcPFCandidates_, originalPFCandidates);

  edm::Handle<reco::PFJetCollection> jets;
  evt.getByLabel(srcJets_, jets);

  std::vector<const reco::PFJet*> selectedJets;
  for ( reco::PFJetCollection::const_iterator jet = jets->begin();
        jet != jets->end(); ++jet ) {
    if ( jet->pt() > minJetPt_ ) selectedJets.push_back(&(*jet));
  }

  if ( jetCorrPayloadName_ != "" ) {
      edm::ESHandle<JetCorrectorParametersCollection> jetCorrParameterSet;
      es.get<JetCorrectionsRecord>().get(jetCorrPayloadName_, jetCorrParameterSet); 
      const JetCorrectorParameters& jetCorrParameters = (*jetCorrParameterSet)[jetCorrUncertaintyTag_];
      delete jecUncertainty_;
      jecUncertainty_ = new JetCorrectionUncertainty(jetCorrParameters);
    }

  std::auto_ptr<reco::PFCandidateCollection> shiftedPFCandidates(new reco::PFCandidateCollection);

  for ( reco::PFCandidateCollection::const_iterator originalPFCandidate = originalPFCandidates->begin();
        originalPFCandidate != originalPFCandidates->end(); ++originalPFCandidate ) {
    
    const reco::PFJet* jet_matched = 0;
    for ( std::vector<const reco::PFJet*>::iterator jet = selectedJets.begin();
          jet != selectedJets.end(); ++jet ) {
      std::vector<reco::PFCandidatePtr> jetConstituents = (*jet)->getPFConstituents();
      for ( std::vector<reco::PFCandidatePtr>::const_iterator jetConstituent = jetConstituents.begin();
            jetConstituent != jetConstituents.end() && !jet_matched; ++jetConstituent ) {
        if ( deltaR(originalPFCandidate->p4(), (*jetConstituent)->p4()) < 1.e-2 ) jet_matched = (*jet);
      }
    }

    double shift = 0.;
    if ( jet_matched ) {
      jecUncertainty_->setJetEta(jet_matched->eta());
      jecUncertainty_->setJetPt(jet_matched->pt());
      
      shift = jecUncertainty_->getUncertainty(true);
    } else {
      shift = unclEnUncertainty_;
    }
    
    reco::Candidate::LorentzVector shiftedPFCandidateP4 = originalPFCandidate->p4();
    shiftedPFCandidateP4 *= (1. + shift);
    
    reco::PFCandidate shiftedPFCandidate(*originalPFCandidate);      
    shiftedPFCandidate.setP4(shiftedPFCandidateP4);
    
    shiftedPFCandidates->push_back(shiftedPFCandidate);
  }
  
  evt.put(shiftedPFCandidates);
}