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CDFMidPointPlugin.cc
//FJSTARTHEADER
// $Id$
//
// Copyright (c) 2005-2021, 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
#include "fastjet/CDFMidPointPlugin.hh"
#include "fastjet/ClusterSequence.hh"
#include "fastjet/Error.hh"
#include <sstream>
// CDF stuff
#include "MidPointAlgorithm.hh"
#include "PhysicsTower.hh"
#include "Cluster.hh"
FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
using namespace std;
using namespace cdf;
thread_safety_helpers::FirstTimeTrue CDFMidPointPlugin::_first_time;
string CDFMidPointPlugin::description () const {
ostringstream desc;
string sm_scale_string = "split-merge uses ";
switch(_sm_scale) {
case SM_pt:
sm_scale_string += "pt";
break;
case SM_Et:
sm_scale_string += "Et";
break;
case SM_mt:
sm_scale_string += "mt";
break;
case SM_pttilde:
sm_scale_string += "pttilde (scalar sum of pts)";
break;
default:
ostringstream err;
err << "Unrecognized split-merge scale choice = " << _sm_scale;
throw Error(err.str());
}
if (cone_area_fraction() == 1) {
desc << "CDF MidPoint jet algorithm, with " ;
} else {
desc << "CDF MidPoint+Searchcone jet algorithm, with ";
}
desc << "seed_threshold = " << seed_threshold () << ", "
<< "cone_radius = " << cone_radius () << ", "
<< "cone_area_fraction = " << cone_area_fraction () << ", "
<< "max_pair_size = " << max_pair_size () << ", "
<< "max_iterations = " << max_iterations () << ", "
<< "overlap_threshold = " << overlap_threshold () << ", "
<< sm_scale_string ;
return desc.str();
}
void CDFMidPointPlugin::run_clustering(ClusterSequence & clust_seq) const {
// print a banner if we run this for the first time
_print_banner(clust_seq.fastjet_banner_stream());
// create the physics towers needed by the CDF code
vector<PhysicsTower> towers;
towers.reserve(clust_seq.jets().size());
for (unsigned i = 0; i < clust_seq.jets().size(); i++) {
LorentzVector fourvect(clust_seq.jets()[i].px(),
clust_seq.jets()[i].py(),
clust_seq.jets()[i].pz(),
clust_seq.jets()[i].E());
PhysicsTower tower(fourvect);
// misuse one of the indices for tracking, since the MidPoint
// implementation doesn't seem to make use of these indices
tower.calTower.iEta = i;
towers.push_back(tower);
}
// prepare the CDF algorithm
MidPointAlgorithm m(_seed_threshold,_cone_radius,_cone_area_fraction,
_max_pair_size,_max_iterations,_overlap_threshold,
MidPointAlgorithm::SplitMergeScale(_sm_scale));
// run the CDF algorithm
std::vector<Cluster> jets;
m.run(towers,jets);
// now transfer the jets back into our own structure -- we will
// mimic the cone code with a sequential recombination sequence in
// which the jets are built up by adding one particle at a time
for(vector<Cluster>::const_iterator jetIter = jets.begin();
jetIter != jets.end(); jetIter++) {
const vector<PhysicsTower> & tower_list = jetIter->towerList;
int jet_k = tower_list[0].calTower.iEta;
int ntow = int(jetIter->towerList.size());
for (int itow = 1; itow < ntow; itow++) {
int jet_i = jet_k;
// retrieve our misappropriated index for the jet
int jet_j = tower_list[itow].calTower.iEta;
// do a fake recombination step with dij=0
double dij = 0.0;
clust_seq.plugin_record_ij_recombination(jet_i, jet_j, dij, jet_k);
}
// 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);
}
// following code is for testing only
//cout << endl;
//for(vector<Cluster>::const_iterator jetIter = jets.begin();
// jetIter != jets.end(); jetIter++) {
// cout << jetIter->fourVector.pt() << " " << jetIter->fourVector.y() << endl;
//}
//cout << "-----------------------------------------------------\n";
//vector<PseudoJet> ourjets(clust_seq.inclusive_jets());
//for (vector<PseudoJet>::const_reverse_iterator ourjet = ourjets.rbegin();
// ourjet != ourjets.rend(); ourjet++) {
// cout << ourjet->perp() << " " << ourjet->rap() << endl;
//}
//cout << endl;
}
// print a banner for reference to the 3rd-party code
void CDFMidPointPlugin::_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 CDF MidPoint plugin for FastJet " << endl;
(*ostr) << "# This is based on an implementation provided by Joey Huston. " << endl;
(*ostr) << "# If you use this plugin, please cite " << endl;
(*ostr) << "# G. C. Blazey et al., hep-ex/0005012. " << 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::CDFMidPointPlugin::run_clustering
virtual void run_clustering(ClusterSequence &) const
given a ClusterSequence that has been filled up with initial particles, the following function should...
Definition CDFMidPointPlugin.cc:89
fastjet::CDFMidPointPlugin::description
virtual std::string description() const
return a textual description of the jet-definition implemented in this plugin
Definition CDFMidPointPlugin.cc:48
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::Error
base class corresponding to errors that can be thrown by FastJet
Definition Error.hh:52