#include <SphericityTensor.h>

Inheritance diagram for JetSubStructureUtils::SphericityTensor:

Collaboration diagram for JetSubStructureUtils::SphericityTensor:

Public Member Functions
virtual std::map< std::string, double >	result (const fastjet::PseudoJet &jet) const

virtual TOut	result (const xAOD::Jet &jet) const

virtual std::map< std::string, double >	result (const xAOD::Jet &jet) const

Detailed Description

Definition at line 11 of file SphericityTensor.h.

Member Function Documentation

◆ result() [1/3]

map< string, double > SphericityTensor::result ( const fastjet::PseudoJet & jet ) const

virtual

Definition at line 15 of file SphericityTensor.cxx.

 {
   map<string, double> Variables;
   Variables["Sphericity"] = -999.*1000.;
   Variables["Aplanarity"] = -999.*1000.;
  
   vector<fastjet::PseudoJet> clusters = boostToCenterOfMass(jet, jet.constituents());
   if(clusters.size() < 2) return Variables;
  
   TMatrixD MomentumTensor(3,3);
   double P2Sum = 0;
  
   for(std::vector<fastjet::PseudoJet>::const_iterator Itr=clusters.begin(); Itr!=clusters.end(); ++Itr) {
     MomentumTensor(0,0) += (*Itr).px()*(*Itr).px();
     MomentumTensor(0,1) += (*Itr).px()*(*Itr).py();
     MomentumTensor(0,2) += (*Itr).px()*(*Itr).pz();
     MomentumTensor(1,0) += (*Itr).py()*(*Itr).px();
     MomentumTensor(1,1) += (*Itr).py()*(*Itr).py();
     MomentumTensor(1,2) += (*Itr).py()*(*Itr).pz();
     MomentumTensor(2,0) += (*Itr).pz()*(*Itr).px();
     MomentumTensor(2,1) += (*Itr).pz()*(*Itr).py();
     MomentumTensor(2,2) += (*Itr).pz()*(*Itr).pz();
  
     P2Sum += (*Itr).px()*(*Itr).px()+(*Itr).py()*(*Itr).py()+(*Itr).pz()*(*Itr).pz();
   }
  
   double Aplanarity = -1;
   double Sphericity = -1;
  
   if(P2Sum > 0) {
     const double inv_P2Sum = 1. / P2Sum;
     for(int i=0; i<3; i++) {
       for(int j=0; j<3; j++) {
         MomentumTensor(i,j) *= inv_P2Sum;
       }
     }
  
     TDecompSVD * aSVD = new TDecompSVD(MomentumTensor);
     TVectorD Lambda = aSVD->GetSig();
  
     Aplanarity = 1.5*Lambda[2];
     Sphericity = 1.5*(Lambda[1]+Lambda[2]);
  
     delete aSVD;
   }
   else {
     return Variables;
   }
  
   Variables["Aplanarity"] = Aplanarity;
   Variables["Sphericity"] = Sphericity;
   return Variables;  
 }

◆ result() [2/3]

virtual TOut JetSubStructureUtils::SubstructureCalculator< TOut >::result

inline

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]

virtual std::map< std::string, double > JetSubStructureUtils::SubstructureCalculator< std::map< std::string, double > >::result ( const xAOD::Jet & jet ) const

inlinevirtualinherited