StRoot: StJetFinder/StjFastJet.cxx Source File

00001 //
00002 // Pibero Djawotho <pibero@tamu.edu>
00003 // Texas A&M University
00004 // 31 Aug 2011
00005 //
00006 // $Id: StjFastJet.cxx,v 1.2 2012/03/10 23:09:53 pibero Exp $
00007 //
00008 // $Log: StjFastJet.cxx,v $
00009 // Revision 1.2  2012/03/10 23:09:53  pibero
00010 // Addeed support for fastjet plugins
00011 //
00012 // Revision 1.1  2011/08/31 17:58:01  pibero
00013 // Support for FastJet
00014 //
00015 // http://www.lpthe.jussieu.fr/~salam/fastjet/
00016 // http://www.star.bnl.gov/HyperNews-star/protected/get/starsoft/8521.html
00017 //
00018 //
00019 
00020 #include <vector>
00021 #include "fastjet/ClusterSequence.hh"
00022 #include "StjFastJet.h"
00023 
00024 void StjFastJet::findJets(JetList& protoJetList, const FourVecList& particleList)
00025 {
00026   // Read in input particles
00027   std::vector<fastjet::PseudoJet> inputParticles;
00028   for (size_t i = 0; i < particleList.size(); ++i) {
00029     fastjet::PseudoJet pseudojet(particleList[i]->px(),particleList[i]->py(),particleList[i]->pz(),particleList[i]->e());
00030     pseudojet.set_user_index(i);
00031     inputParticles.push_back(pseudojet);
00032   }
00033 
00034   // Run the jet clustering with the above jet definition
00035   fastjet::ClusterSequence clusterSequence(inputParticles,jetDefinition());
00036 
00037   // Extract inclusive jets with pt > ptmin
00038   std::vector<fastjet::PseudoJet> inclusiveJets = clusterSequence.inclusive_jets(mPars.ptMin());
00039   for (size_t i = 0; i < inclusiveJets.size(); ++i) {
00040     StProtoJet protojet;
00041     std::vector<fastjet::PseudoJet> constituents = clusterSequence.constituents(inclusiveJets[i]);
00042     for (size_t j = 0; j < constituents.size(); ++j) {
00043       const_cast<FourVecList&>(protojet.list()).push_back(particleList[constituents[j].user_index()]);
00044     }
00045     protojet.update();
00046     protoJetList.push_back(protojet);
00047   }
00048 }
00049 
00050 fastjet::JetDefinition StjFastJet::jetDefinition() const
00051 {
00052   return (mPars.jetAlgorithm() == fastjet::plugin_algorithm)
00053     ? fastjet::JetDefinition(static_cast<fastjet::JetDefinition::Plugin*>(mPars.plugin()))
00054     : fastjet::JetDefinition(static_cast<fastjet::JetAlgorithm>(mPars.jetAlgorithm()),
00055                              mPars.Rparam(),
00056                              static_cast<fastjet::RecombinationScheme>(mPars.recombinationScheme()),
00057                              static_cast<fastjet::Strategy>(mPars.strategy()));
00058 }