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ATLASConePlugin.cc
//FJSTARTHEADER
// $Id$
//
// Copyright (c) 2007-2021, Matteo Cacciari, Gavin P. Salam and Gregory Soyez
//
//----------------------------------------------------------------------
// This file is part of FastJet.
//
// FastJet is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// The algorithms that underlie FastJet have required considerable
// development. They are described in the original FastJet paper,
// hep-ph/0512210 and in the manual, arXiv:1111.6097. If you use
// FastJet as part of work towards a scientific publication, please
// quote the version you use and include a citation to the manual and
// optionally also to hep-ph/0512210.
//
// FastJet is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with FastJet. If not, see <http://www.gnu.org/licenses/>.
//----------------------------------------------------------------------
//FJENDHEADER
// fastjet stuff
#include "fastjet/ClusterSequence.hh"
#include "fastjet/ATLASConePlugin.hh"
// SpartyJet stuff
#include "CommonUtils.hh"
#include "JetConeFinderTool.hh"
#include "JetSplitMergeTool.hh"
// other stuff
#include <vector>
#include <sstream>
FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
using namespace std;
thread_safety_helpers::FirstTimeTrue ATLASConePlugin::_first_time;
string ATLASConePlugin::description () const {
ostringstream desc;
desc << "ATLASCone plugin with R = "<< _radius
<< ", seed threshold = " << _seedPt
<< ", overlap threshold f = " << _f;
return desc.str();
}
void ATLASConePlugin::run_clustering(ClusterSequence & clust_seq) const {
// print a banner if we run this for the first time
_print_banner(clust_seq.fastjet_banner_stream());
// transfer the list of PseudoJet into a atlas::Jet::jet_list_t
// jet_list_t is a vector<Jet*>
// We set the index of the 4-vect to trace the constituents at the end
//------------------------------------------------------------------
// cout << "ATLASConePlugin: transferring vectors from ClusterSequence" << endl;
atlas::JetConeFinderTool::jetcollection_t jets_ptr;
vector<atlas::Jet*> particles_ptr;
for (unsigned int i=0 ; i<clust_seq.jets().size() ; i++) {
const PseudoJet & mom = clust_seq.jets()[i];
// first create the particle
atlas::Jet *particle = new atlas::Jet(mom.px(), mom.py(), mom.pz(), mom.E(), i);
particles_ptr.push_back(particle);
// then add it to the list of particles we'll use for the clustering
atlas::Jet *jet = new atlas::Jet;
jet->set_index(particle->index());
jet->addConstituent(particle);
// and finally add that one to the list of jets
jets_ptr.push_back(jet);
}
// cout << "ATLASCone: " << jets_ptr.size() << " particles to cluster" << endl;
// search the stable cones
//------------------------------------------------------------------
// cout << "ATLASConePlugin: searching for stable cones" << endl;
atlas::JetConeFinderTool stable_cone_finder;
// set the parameters
stable_cone_finder.m_coneR = _radius;
stable_cone_finder.m_seedPt = _seedPt;
// really do the search.
// Note that the list of protocones is returned
// through the argument
stable_cone_finder.execute(jets_ptr);
// cout << "ATLASCone: " << jets_ptr.size() << " stable cones found" << endl;
// perform the split-merge
//------------------------------------------------------------------
// cout << "ATLASConePlugin: running the split-merge" << endl;
atlas::JetSplitMergeTool split_merge;
// set the parameters
split_merge.m_f = _f;
// do the work
// again, the list of jets is returned through the argument
split_merge.execute(&jets_ptr);
// cout << "ATLASCone: " << jets_ptr.size() << " jets after split--merge" << endl;
// build the FastJet jets (a la SISConePlugin)
//------------------------------------------------------------------
// cout << "ATLASConePlugin: backporting jets to the ClusterSequence" << endl;
for (atlas::Jet::jet_list_t::iterator jet_it = jets_ptr.begin() ;
jet_it != jets_ptr.end(); jet_it++){
// iterate over the constituents, starting from the first one
// that we just take as a reference
atlas::Jet::constit_vect_t::iterator constit_it = (*jet_it)->firstConstituent();
// cout << " atlas: jet has " << (*jet_it)->getConstituentNum() << " constituents" << endl;
int jet_k = (*constit_it)->index();
constit_it++;
// loop over the remaining particles
while (constit_it != (*jet_it)->lastConstituent()){
// take the last result of the merge
int jet_i = jet_k;
// and the next element of the jet
int jet_j = (*constit_it)->index();
// and merge them (with a fake dij)
double dij = 0.0;
// create the new jet by hand so that we can adjust its user index
// Note again the use of the E-scheme recombination here!
PseudoJet newjet = clust_seq.jets()[jet_i] + clust_seq.jets()[jet_j];
clust_seq.plugin_record_ij_recombination(jet_i, jet_j, dij, newjet, jet_k);
// jump to the next constituent
constit_it++;
}
// we have merged all the jet's particles into a single object, so now
// "declare" it to be a beam (inclusive) jet.
// [NB: put a sensible looking d_iB just to be nice...]
double d_iB = clust_seq.jets()[jet_k].perp2();
clust_seq.plugin_record_iB_recombination(jet_k, d_iB);
}
// cout << "ATLASConePlugin: Bye" << endl;
clear_list(particles_ptr);
clear_list(jets_ptr);
}
// print a banner for reference to the 3rd-party code
void ATLASConePlugin::_print_banner(ostream *ostr) const{
if (! _first_time()) return;
// make sure the user has not set the banner stream to NULL
if (!ostr) return;
(*ostr) << "#-------------------------------------------------------------------------" << endl;
(*ostr) << "# You are running the ATLAS Cone plugin for FastJet " << endl;
(*ostr) << "# Original code from SpartyJet; interface by the FastJet authors " << endl;
(*ostr) << "# If you use this plugin, please cite " << endl;
(*ostr) << "# P.A. Delsart, K. Geerlings, J. Huston, B. Martin and C. Vermilion, " << endl;
(*ostr) << "# SpartyJet, http://projects.hepforge.org/spartyjet " << endl;
(*ostr) << "# in addition to the usual FastJet reference. " << endl;
(*ostr) << "#-------------------------------------------------------------------------" << endl;
// make sure we really have the output done.
ostr->flush();
}
FASTJET_END_NAMESPACE // defined in fastjet/internal/base.hh
fastjet::ATLASConePlugin::run_clustering
virtual void run_clustering(ClusterSequence &) const
given a ClusterSequence that has been filled up with initial particles, the following function should...
Definition ATLASConePlugin.cc:58
fastjet::ATLASConePlugin::description
virtual std::string description() const
return a textual description of the jet-definition implemented in this plugin
Definition ATLASConePlugin.cc:50
fastjet::ClusterSequence
deals with clustering
Definition ClusterSequence.hh:63
fastjet::ClusterSequence::plugin_record_iB_recombination
void plugin_record_iB_recombination(int jet_i, double diB)
record the fact that there has been a recombination between jets()[jet_i] and the beam,...
Definition ClusterSequence.hh:343
fastjet::ClusterSequence::jets
const std::vector< PseudoJet > & jets() const
allow the user to access the internally stored _jets() array, which contains both the initial particl...
Definition ClusterSequence.hh:1003
fastjet::ClusterSequence::fastjet_banner_stream
static std::ostream * fastjet_banner_stream()
returns a pointer to the stream to be used to print banners (cout by default).
Definition ClusterSequence.hh:579
fastjet::ClusterSequence::plugin_record_ij_recombination
void plugin_record_ij_recombination(int jet_i, int jet_j, double dij, int &newjet_k)
record the fact that there has been a recombination between jets()[jet_i] and jets()[jet_k],...
Definition ClusterSequence.hh:326
fastjet::PseudoJet
Class to contain pseudojets, including minimal information of use to jet-clustering routines.
Definition PseudoJet.hh:68