FastJet 3.0.2
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00001 //STARTHEADER 00002 // $Id: CDFMidPointPlugin.cc 2777 2011-11-25 15:01:56Z soyez $ 00003 // 00004 // Copyright (c) 2005-2011, Matteo Cacciari, Gavin P. Salam and Gregory Soyez 00005 // 00006 //---------------------------------------------------------------------- 00007 // This file is part of FastJet. 00008 // 00009 // FastJet is free software; you can redistribute it and/or modify 00010 // it under the terms of the GNU General Public License as published by 00011 // the Free Software Foundation; either version 2 of the License, or 00012 // (at your option) any later version. 00013 // 00014 // The algorithms that underlie FastJet have required considerable 00015 // development and are described in hep-ph/0512210. If you use 00016 // FastJet as part of work towards a scientific publication, please 00017 // include a citation to the FastJet paper. 00018 // 00019 // FastJet is distributed in the hope that it will be useful, 00020 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00021 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00022 // GNU General Public License for more details. 00023 // 00024 // You should have received a copy of the GNU General Public License 00025 // along with FastJet. If not, see <http://www.gnu.org/licenses/>. 00026 //---------------------------------------------------------------------- 00027 //ENDHEADER 00028 00029 #include "fastjet/CDFMidPointPlugin.hh" 00030 #include "fastjet/ClusterSequence.hh" 00031 #include "fastjet/Error.hh" 00032 #include <sstream> 00033 00034 // CDF stuff 00035 #include "MidPointAlgorithm.hh" 00036 #include "PhysicsTower.hh" 00037 #include "Cluster.hh" 00038 00039 FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh 00040 00041 using namespace std; 00042 using namespace cdf; 00043 00044 bool CDFMidPointPlugin::_first_time = true; 00045 00046 string CDFMidPointPlugin::description () const { 00047 ostringstream desc; 00048 00049 string sm_scale_string = "split-merge uses "; 00050 switch(_sm_scale) { 00051 case SM_pt: 00052 sm_scale_string += "pt"; 00053 break; 00054 case SM_Et: 00055 sm_scale_string += "Et"; 00056 break; 00057 case SM_mt: 00058 sm_scale_string += "mt"; 00059 break; 00060 case SM_pttilde: 00061 sm_scale_string += "pttilde (scalar sum of pts)"; 00062 break; 00063 default: 00064 ostringstream err; 00065 err << "Unrecognized split-merge scale choice = " << _sm_scale; 00066 throw Error(err.str()); 00067 } 00068 00069 00070 if (cone_area_fraction() == 1) { 00071 desc << "CDF MidPoint jet algorithm, with " ; 00072 } else { 00073 desc << "CDF MidPoint+Searchcone jet algorithm, with "; 00074 } 00075 desc << "seed_threshold = " << seed_threshold () << ", " 00076 << "cone_radius = " << cone_radius () << ", " 00077 << "cone_area_fraction = " << cone_area_fraction () << ", " 00078 << "max_pair_size = " << max_pair_size () << ", " 00079 << "max_iterations = " << max_iterations () << ", " 00080 << "overlap_threshold = " << overlap_threshold () << ", " 00081 << sm_scale_string ; 00082 00083 return desc.str(); 00084 } 00085 00086 00087 void CDFMidPointPlugin::run_clustering(ClusterSequence & clust_seq) const { 00088 // print a banner if we run this for the first time 00089 _print_banner(clust_seq.fastjet_banner_stream()); 00090 00091 // create the physics towers needed by the CDF code 00092 vector<PhysicsTower> towers; 00093 towers.reserve(clust_seq.jets().size()); 00094 for (unsigned i = 0; i < clust_seq.jets().size(); i++) { 00095 LorentzVector fourvect(clust_seq.jets()[i].px(), 00096 clust_seq.jets()[i].py(), 00097 clust_seq.jets()[i].pz(), 00098 clust_seq.jets()[i].E()); 00099 PhysicsTower tower(fourvect); 00100 // misuse one of the indices for tracking, since the MidPoint 00101 // implementation doesn't seem to make use of these indices 00102 tower.calTower.iEta = i; 00103 towers.push_back(tower); 00104 } 00105 00106 // prepare the CDF algorithm 00107 MidPointAlgorithm m(_seed_threshold,_cone_radius,_cone_area_fraction, 00108 _max_pair_size,_max_iterations,_overlap_threshold, 00109 MidPointAlgorithm::SplitMergeScale(_sm_scale)); 00110 00111 // run the CDF algorithm 00112 std::vector<Cluster> jets; 00113 m.run(towers,jets); 00114 00115 00116 // now transfer the jets back into our own structure -- we will 00117 // mimic the cone code with a sequential recombination sequence in 00118 // which the jets are built up by adding one particle at a time 00119 for(vector<Cluster>::const_iterator jetIter = jets.begin(); 00120 jetIter != jets.end(); jetIter++) { 00121 const vector<PhysicsTower> & tower_list = jetIter->towerList; 00122 int jet_k = tower_list[0].calTower.iEta; 00123 00124 int ntow = int(jetIter->towerList.size()); 00125 for (int itow = 1; itow < ntow; itow++) { 00126 int jet_i = jet_k; 00127 // retrieve our misappropriated index for the jet 00128 int jet_j = tower_list[itow].calTower.iEta; 00129 // do a fake recombination step with dij=0 00130 double dij = 0.0; 00131 clust_seq.plugin_record_ij_recombination(jet_i, jet_j, dij, jet_k); 00132 } 00133 00134 // NB: put a sensible looking d_iB just to be nice... 00135 double d_iB = clust_seq.jets()[jet_k].perp2(); 00136 clust_seq.plugin_record_iB_recombination(jet_k, d_iB); 00137 } 00138 00139 00140 // following code is for testing only 00141 //cout << endl; 00142 //for(vector<Cluster>::const_iterator jetIter = jets.begin(); 00143 // jetIter != jets.end(); jetIter++) { 00144 // cout << jetIter->fourVector.pt() << " " << jetIter->fourVector.y() << endl; 00145 //} 00146 //cout << "-----------------------------------------------------\n"; 00147 //vector<PseudoJet> ourjets(clust_seq.inclusive_jets()); 00148 //for (vector<PseudoJet>::const_reverse_iterator ourjet = ourjets.rbegin(); 00149 // ourjet != ourjets.rend(); ourjet++) { 00150 // cout << ourjet->perp() << " " << ourjet->rap() << endl; 00151 //} 00152 //cout << endl; 00153 } 00154 00155 // print a banner for reference to the 3rd-party code 00156 void CDFMidPointPlugin::_print_banner(ostream *ostr) const{ 00157 if (! _first_time) return; 00158 _first_time=false; 00159 00160 // make sure the user has not set the banner stream to NULL 00161 if (!ostr) return; 00162 00163 (*ostr) << "#-------------------------------------------------------------------------" << endl; 00164 (*ostr) << "# You are running the CDF MidPoint plugin for FastJet " << endl; 00165 (*ostr) << "# This is based on an implementation provided by Joey Huston. " << endl; 00166 (*ostr) << "# If you use this plugin, please cite " << endl; 00167 (*ostr) << "# G. C. Blazey et al., hep-ex/0005012. " << endl; 00168 (*ostr) << "# in addition to the usual FastJet reference. " << endl; 00169 (*ostr) << "#-------------------------------------------------------------------------" << endl; 00170 00171 // make sure we really have the output done. 00172 ostr->flush(); 00173 } 00174 00175 FASTJET_END_NAMESPACE // defined in fastjet/internal/base.hh