FastJet 3.0.2
D0RunIIConePlugin.cc
00001 //STARTHEADER
00002 // $Id: D0RunIIConePlugin.cc 2815 2011-12-13 21:54:40Z 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/D0RunIIConePlugin.hh"
00030 #include "fastjet/ClusterSequence.hh"
00031 #include "fastjet/Error.hh"
00032 #include <sstream>
00033 
00034 // D0 stuff
00035 #include <list>
00036 #include "ILConeAlgorithm.hpp"
00037 #include "HepEntity.h"
00038 
00039 FASTJET_BEGIN_NAMESPACE      // defined in fastjet/internal/base.hh
00040 
00041 using namespace std;
00042 using namespace d0;
00043 
00044 const double D0RunIIConePlugin::_DEFAULT_split_ratio              = 0.5  ; // overlap threshold
00045 const double D0RunIIConePlugin::_DEFAULT_far_ratio                = 0.5  ;
00046 const double D0RunIIConePlugin::_DEFAULT_Et_min_ratio             = 0.5  ;
00047 const bool   D0RunIIConePlugin::_DEFAULT_kill_duplicate           = true ;
00048 const double D0RunIIConePlugin::_DEFAULT_duplicate_dR             = 0.005; 
00049 const double D0RunIIConePlugin::_DEFAULT_duplicate_dPT            = 0.01 ; 
00050 const double D0RunIIConePlugin::_DEFAULT_search_factor            = 1.0  ; 
00051 const double D0RunIIConePlugin::_DEFAULT_pT_min_leading_protojet  = 0.   ; 
00052 const double D0RunIIConePlugin::_DEFAULT_pT_min_second_protojet   = 0.   ;
00053 const int    D0RunIIConePlugin::_DEFAULT_merge_max                = 10000; 
00054 const double D0RunIIConePlugin::_DEFAULT_pT_min_nomerge           = 0.   ;
00055 
00056 bool D0RunIIConePlugin::_first_time = true;
00057 
00058 string D0RunIIConePlugin::description () const {
00059   ostringstream desc;
00060   
00061   desc << "D0 Run II Improved Legacy (midpoint) cone jet algorithm, with ";
00062   desc << "cone_radius = "        << cone_radius        () << ", "
00063        << "min_jet_Et = "         << min_jet_Et         () << ", " 
00064        << "split_ratio = "        << split_ratio        ();
00065 
00066   return desc.str();
00067 }
00068 
00069 
00070 void D0RunIIConePlugin::run_clustering(ClusterSequence & clust_seq) const {
00071   // print a banner if we run this for the first time
00072   _print_banner(clust_seq.fastjet_banner_stream());
00073  
00074   // create the entities needed by the D0 code
00075   vector<HepEntity> entities(clust_seq.jets().size());
00076   list<const HepEntity * > ensemble;
00077   for (unsigned i = 0; i < clust_seq.jets().size(); i++) {
00078     entities[i].Fill(clust_seq.jets()[i].E(),
00079                      clust_seq.jets()[i].px(),
00080                      clust_seq.jets()[i].py(),
00081                      clust_seq.jets()[i].pz(),
00082                      i);
00083     // use only the particles that do not have infinite rapidity
00084     if (abs(entities[i].pz) < entities[i].E) {
00085       ensemble.push_back(& (entities[i]));
00086     }
00087   }
00088 
00089   // prepare the D0 algorithm
00090   ILConeAlgorithm<HepEntity> 
00091     ilegac(cone_radius(), 
00092            min_jet_Et(), 
00093            split_ratio(),
00094            far_ratio(), 
00095            Et_min_ratio(), 
00096            kill_duplicate(), 
00097            duplicate_dR(), 
00098            duplicate_dPT(), 
00099            search_factor(), 
00100            pT_min_leading_protojet(), 
00101            pT_min_second_protojet(), 
00102            merge_max(), 
00103            pT_min_nomerge());
00104 
00105   // run the algorithm
00106   float Item_ET_Threshold = 0.;
00107   list<HepEntity> jets;
00108   ilegac.makeClusters(jets, ensemble, Item_ET_Threshold);
00109 
00110   // now transfer the information about the jets into the
00111   // FastJet structure
00112   for(int i = ilegac.ilcv.size()-1; i >= 0; i--) {
00113     
00114     std::list<const HepEntity*> tlist = ilegac.ilcv[i].LItems();
00115     std::list<const HepEntity*>::iterator tk;
00116     
00117     // get first particle in list
00118     tk = tlist.begin();
00119 
00120     // if there is no particle, just discard it
00121     // Note: this unexpected behaviour has been observed when the
00122     //       min_jet_Et parameter was set to 0
00123     if (tk==tlist.end())
00124       continue;
00125 
00126     int jet_k = (*tk)->index;
00127     // now merge with remaining particles in list
00128     tk++;
00129     for (; tk != tlist.end(); tk++) {
00130       int jet_i = jet_k;
00131       int jet_j = (*tk)->index;
00132       // do a fake recombination step with dij=0
00133       double dij = 0.0;
00134       clust_seq.plugin_record_ij_recombination(jet_i, jet_j, dij, jet_k);
00135     }
00136 
00137     // NB: put a sensible looking d_iB just to be nice...
00138     double d_iB = clust_seq.jets()[jet_k].perp2();
00139     clust_seq.plugin_record_iB_recombination(jet_k, d_iB);
00140 
00141   }
00142 }
00143 
00144 // print a banner for reference to the 3rd-party code
00145 void D0RunIIConePlugin::_print_banner(ostream *ostr) const{
00146   if (! _first_time) return;
00147   _first_time=false;
00148 
00149   // make sure the user has not set the banner stream to NULL
00150   if (!ostr) return;  
00151 
00152   (*ostr) << "#--------------------------------------------------------------------------" << endl;
00153   (*ostr) << "# You are running the D0 Run II Cone plugin for FastJet                    " << endl;
00154   (*ostr) << "# Original code by the D0 collaboration, provided by Lars Sonnenschein;    " << endl;
00155   (*ostr) << "# interface by FastJet authors                                             " << endl;
00156   (*ostr) << "# If you use this plugin, please cite                                      " << endl;
00157   (*ostr) << "#   G. C. Blazey et al., hep-ex/0005012                                    " << endl;
00158   (*ostr) << "#   V. M. Abazov et al. [D0 Collaboration], arXiv:1110.3771 [hep-ex]       " << endl; 
00159   (*ostr) << "# in addition to the usual FastJet reference.                              " << endl;
00160   (*ostr) << "#--------------------------------------------------------------------------" << endl;
00161 
00162   // make sure we really have the output done.
00163   ostr->flush();
00164 }
00165 
00166 FASTJET_END_NAMESPACE      // defined in fastjet/internal/base.hh
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