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FastJetBaseWrapper Class Reference

#include <RecoJets/JetAlgorithms/interface/FastJetBaseWrapper.h>

Inheritance diagram for FastJetBaseWrapper:

List of all members.

Public Member Functions
	FastJetBaseWrapper (const edm::ParameterSet &fConfig)
void	run (const JetReco::InputCollection &fInput, JetReco::OutputCollection *fOutput)
virtual	~FastJetBaseWrapper ()
Protected Attributes
fastjet::JetDefinition *	mJetDefinition
Private Attributes
fastjet::GhostedAreaSpec *	mActiveArea
double	mJetPtMin

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Detailed Description

Definition at line 13 of file FastJetBaseWrapper.h.

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Constructor & Destructor Documentation

FastJetBaseWrapper::FastJetBaseWrapper

(

const edm::ParameterSet &

fConfig

)

Definition at line 24 of file FastJetBaseWrapper.cc.

References edm::ParameterSet::getParameter(), mActiveArea, and mJetPtMin.

  : mJetDefinition (0), 
    mActiveArea (0)
{
  mJetPtMin = fConfig.getParameter<double> ("jetPtMin");
  if (fConfig.getParameter<std::string> ("UE_Subtraction") == "yes") {            // accept pilup subtraction parameters
    double ghostEtaMax = fConfig.getParameter<double> ("Ghost_EtaMax");   //default Ghost_EtaMax should be 6
    int activeAreaRepeats = fConfig.getParameter<int> ("Active_Area_Repeats");   //default Active_Area_Repeats 5
    double ghostArea = fConfig.getParameter<double> ("GhostArea");   //default GhostArea 0.01
    mActiveArea = new fastjet::ActiveAreaSpec (ghostEtaMax, activeAreaRepeats, ghostArea);
  }
}

FastJetBaseWrapper::~FastJetBaseWrapper

(

)

[virtual]

Definition at line 38 of file FastJetBaseWrapper.cc.

References mActiveArea, and mJetDefinition.

                                       {
  delete mJetDefinition;
  delete mActiveArea;
}

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Member Function Documentation

void FastJetBaseWrapper::run	(	const JetReco::InputCollection &	fInput,
		JetReco::OutputCollection *	fOutput
	)

Definition at line 43 of file FastJetBaseWrapper.cc.

References c, i, iggi_31X_cfg::input, metsig::jet, pfTauBenchmarkGeneric_cfi::jets, mActiveArea, mJetDefinition, mJetPtMin, and p4.

Referenced by cms::KtPilupSubtractionJetProducer::runAlgorithm().

                                                                                                   {
  if (!fOutput) return;
  fOutput->clear();
  
  // convert inputs
  std::vector<fastjet::PseudoJet> fjInputs;
  fjInputs.reserve (fInput.size());
  
  JetReco::InputCollection::const_iterator input = fInput.begin();
  for (unsigned i = 0; i < fInput.size(); ++i) {
    const JetReco::InputItem& c = fInput[i];
    fjInputs.push_back (fastjet::PseudoJet (c->px(),c->py(),c->pz(),c->energy()));
    fjInputs.back().set_user_index(i);
  }
   
   // create an object that represents your choice of jet finder and 
   // the associated parameters
   // run the jet clustering with the above jet definition

   // here we need to keep both pointers, as "area" interfaces are missing in base class
   fastjet::ClusterSequenceActiveArea* clusterSequenceWithArea = 0;
   fastjet::ClusterSequenceWithArea* clusterSequence = 0;
   if (mActiveArea) {
     clusterSequenceWithArea = new fastjet::ClusterSequenceActiveArea (fjInputs, *mJetDefinition, *mActiveArea);
     clusterSequence = clusterSequenceWithArea;
   }
   else {
     clusterSequence = new fastjet::ClusterSequenceWithArea (fjInputs, *mJetDefinition);
   }
   // retrieve jets for selected mode
   std::vector<fastjet::PseudoJet> jets = clusterSequence->inclusive_jets (mJetPtMin);

   // get PU pt
   double median_Pt_Per_Area = clusterSequenceWithArea ? clusterSequenceWithArea->pt_per_unit_area() : 0.;

   // process found jets
   for (std::vector<fastjet::PseudoJet>::const_iterator jet=jets.begin(); jet!=jets.end();++jet) {
     // jet itself
     double px=jet->px();
     double py=jet->py();
     double pz=jet->pz();
     double E=jet->E();
     double jetArea=clusterSequence->area(*jet);
     double pu=0.;
     // PU subtraction
     if (clusterSequenceWithArea) {
       fastjet::PseudoJet pu_p4 = median_Pt_Per_Area * clusterSequenceWithArea->area_4vector(*jet);
       pu = pu_p4.E();
       if (pu_p4.perp2() >= jet->perp2() || pu_p4.E() >= jet->E()) { // if the correction is too large, set the jet to zero
         px = py = pz = E = 0.;
       } 
       else {   // otherwise do an E-scheme subtraction
         px -= pu_p4.px();
         py -= pu_p4.py();
         pz -= pu_p4.pz();
         E -= pu_p4.E();
       }
     }
     math::XYZTLorentzVector p4(px,py,pz,E);
     // constituents
     std::vector<fastjet::PseudoJet> fastjet_constituents = clusterSequence->constituents(*jet);
     JetReco::InputCollection jetConstituents; 
     jetConstituents.reserve (fastjet_constituents.size());
     for (std::vector<fastjet::PseudoJet>::const_iterator itConst=fastjet_constituents.begin();
          itConst!=fastjet_constituents.end();itConst++){
       jetConstituents.push_back(fInput[(*itConst).user_index()]);
     }
     // Build ProtoJet
     fOutput->push_back(ProtoJet(p4,jetConstituents));
     fOutput->back().setJetArea (jetArea);
     fOutput->back().setPileup (pu);
   }
   // cleanup
   if (clusterSequenceWithArea) delete clusterSequenceWithArea;
   else delete clusterSequence; // sigh... No plymorphism in fastjet
}

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Member Data Documentation

fastjet::GhostedAreaSpec* FastJetBaseWrapper::mActiveArea [private]

Definition at line 21 of file FastJetBaseWrapper.h.

Referenced by FastJetBaseWrapper(), run(), and ~FastJetBaseWrapper().

fastjet::JetDefinition* FastJetBaseWrapper::mJetDefinition [protected]

Definition at line 19 of file FastJetBaseWrapper.h.

Referenced by CambridgeAlgorithmWrapper::CambridgeAlgorithmWrapper(), CDFMidpointAlgorithmWrapper::CDFMidpointAlgorithmWrapper(), KtJetAlgorithmWrapper::KtJetAlgorithmWrapper(), run(), SISConeAlgorithmWrapper::SISConeAlgorithmWrapper(), and ~FastJetBaseWrapper().

double FastJetBaseWrapper::mJetPtMin [private]

Definition at line 22 of file FastJetBaseWrapper.h.

Referenced by FastJetBaseWrapper(), and run().

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The documentation for this class was generated from the following files:

• RecoJets/JetAlgorithms/interface/FastJetBaseWrapper.h
• RecoJets/JetAlgorithms/src/FastJetBaseWrapper.cc

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