JetSubStructureUtils::Qw Class Reference

#include <Qw.h>

Inheritance diagram for JetSubStructureUtils::Qw:

Collaboration diagram for JetSubStructureUtils::Qw:

Public Types
enum	QwVariant { Normal , MassCut , SmallSubjets }
	describes the differnt calculation variants More...

Public Member Functions
	Qw (QwVariant mode=Normal, double p=-1, fastjet::JetAlgorithm jetalg=fastjet::kt_algorithm)
virtual double	result (const fastjet::PseudoJet &jet) const
	SubstructureCalculator interface.
virtual double	result (std::vector< fastjet::PseudoJet > &constituents) const
	Implementation of the calculation.
virtual TOut	result (const xAOD::Jet &jet) const

Private Attributes
QwVariant	m_vMode
fastjet::JetDefinition	m_jetdef
double	m_massCut

Detailed Description

Definition at line 34 of file Qw.h.

Member Enumeration Documentation

QwVariant

enum JetSubStructureUtils::Qw::QwVariant

describes the differnt calculation variants

Enumerator
Normal
MassCut
SmallSubjets

Definition at line 38 of file Qw.h.

                   {
      Normal,
      MassCut,
      SmallSubjets,
    };

Constructor & Destructor Documentation

Qw()

Qw::Qw	(	QwVariant	mode = Normal,
		double	p = -1,
		fastjet::JetAlgorithm	jetalg = fastjet::kt_algorithm )

Definition at line 13 of file Qw.cxx.

                                                           : m_vMode(mode), m_jetdef(), m_massCut(-1) {
 
  switch (mode ) {
  case Normal:
  case MassCut:
    m_jetdef = fastjet::JetDefinition(jetalg, 1.5) ;
    m_massCut = p;
    break;
  case SmallSubjets:
    if(p==-1) p = 0.2; 
    m_jetdef = fastjet::JetDefinition(jetalg, p) ;
    break;
  }
}

Member Function Documentation

result() [1/3]

double Qw::result ( const fastjet::PseudoJet & jet ) const

virtual

SubstructureCalculator interface.

Definition at line 28 of file Qw.cxx.

{
  std::vector<fastjet::PseudoJet> constituents = jet.constituents();
  return result(constituents);
}

result() [2/3]

virtual TOut JetSubStructureUtils::SubstructureCalculator< TOut >::result ( const xAOD::Jet & jet ) const

inlinevirtual

Reimplemented from JetSubStructureUtils::SubstructureCalculator< double >.

Definition at line 25 of file SubstructureCalculator.h.

                                                    {
        // PS 4/18 master developent
        // std::vector<fastjet::PseudoJet> constit_pseudojets =
        //   jet::JetConstituentFiller::constituentPseudoJets(jet);
 
        std::vector<fastjet::PseudoJet> constit_pseudojets;
        std::transform(jet.getConstituents().begin(),
                       jet.getConstituents().end(),
                       std::back_inserter(constit_pseudojets),
                       [](const auto& c){
                         const xAOD::IParticle* ip = c->rawConstituent();
                         return
                           // fastjet::PseudoJet((c->rawConstituent())->p4());
                           fastjet::PseudoJet(ip->p4());
                       });
 
        fastjet::PseudoJet pjet = fastjet::join(constit_pseudojets);
 
        return result(pjet);
      }

result() [3/3]

double Qw::result ( std::vector< fastjet::PseudoJet > & constituents ) const

virtual

Implementation of the calculation.

Definition at line 53 of file Qw.cxx.

                                                                 {
 
  // deal with extreme cases first.
  // early exit in this cases.
  size_t nconst = constituents.size();
  if( nconst < 3 ) return 0;
 
  // Build the subjets 
  fastjet::ClusterSequence cs(constituents, m_jetdef);
 
  double scaleF = 1.;
 
  std::vector<fastjet::PseudoJet> outjets; 
  
  switch( m_vMode) {
  case Normal :
    outjets= cs.exclusive_jets(3);
    //std::cout << " Normal mode :  scaleF " << scaleF << "  m1="<< outjets[0].m() << std::endl;
 
    break;
 
  case MassCut: {
    outjets= cs.exclusive_jets(3);
    fastjet::PseudoJet sumTot(0,0,0,0) ;
    sumTot = outjets[0] + outjets[1] + outjets[2];
 
    // make sure we deal only with subjets with mass < m_massCut
    std::vector<fastjet::PseudoJet> tmp_subjets; tmp_subjets.reserve(4);
    decomposeToJetMass(outjets[0], m_massCut , tmp_subjets);
    decomposeToJetMass(outjets[1], m_massCut , tmp_subjets);
    decomposeToJetMass(outjets[2], m_massCut , tmp_subjets);
    // Take the 3 highest pt subjets.
    outjets = fastjet::sorted_by_pt( tmp_subjets) ;
    outjets.resize(3);
 
 
    // resum the 3 highest pt subjets to compute the scale factor.
    fastjet::PseudoJet  sumSubJ(0,0,0,0);
    sumSubJ = outjets[0] + outjets[1] + outjets[2];
    scaleF = sumTot.pt()/sumSubJ.pt();    
    //    std::cout << " MassCut mode :  scaleF " << scaleF << "  m1="<< outjets[0].m() << std::endl;
 
  }
    break;
  case SmallSubjets: {
    outjets = fastjet::sorted_by_pt(cs.inclusive_jets());
    
    // deal with extreme case first.
    // early exit in this case.
    size_t nsubjets = outjets.size();
    if( nsubjets < 3 ) return 0;
 
    // compute the scale factor : as we choose only the 1st 3 subjets, 
    // we scale back the contribution of these 3 subjets to the total Pt.
    fastjet::PseudoJet sumTot(0,0,0,0), sumSubJ(0,0,0,0);
    for( fastjet::PseudoJet& c: constituents) sumTot+=c;
 
    // take the 3 highest subjets only
    outjets.resize(3);
 
    for( fastjet::PseudoJet& c: outjets ) sumSubJ+=c;
    scaleF = sumTot.pt()/sumSubJ.pt();
    //    std::cout << " SmallSubjets mode :  scaleF " << scaleF << "  m1="<< outjets[0].m() << std::endl;
  }
    break;
  }
 
  double m12 = (outjets[0]+outjets[1]).m();
  double m23 = (outjets[2]+outjets[1]).m();
  double m13 = (outjets[2]+outjets[0]).m();
 
  //  std::cout << " ---------> qw="<< scaleF*std::min(m12, std::min(m23,m13) ) << std::endl;
  return scaleF*std::min(m12, std::min(m23,m13) );
}

Member Data Documentation

m_jetdef

fastjet::JetDefinition JetSubStructureUtils::Qw::m_jetdef

private

Definition at line 56 of file Qw.h.

m_massCut

double JetSubStructureUtils::Qw::m_massCut

private

Definition at line 58 of file Qw.h.

m_vMode

QwVariant JetSubStructureUtils::Qw::m_vMode

private

Definition at line 55 of file Qw.h.

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

• Qw.h
• Qw.cxx