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ClusterSequencePassiveArea.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/ClusterSequencePassiveArea.hh"
#include "fastjet/ClusterSequenceVoronoiArea.hh"
FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
using namespace std;
//----------------------------------------------------------------------
/// global routine for initialising and running a passive area that is
/// correct in general, but that chooses an optimal approach for
/// various special cases.
void ClusterSequencePassiveArea::_initialise_and_run_PA (
const JetDefinition & jet_def_in,
const GhostedAreaSpec & area_spec,
const bool & writeout_combinations) {
if (jet_def_in.jet_algorithm() == kt_algorithm) {
// first run the passive area
ClusterSequenceVoronoiArea csva(_jets,jet_def_in,VoronoiAreaSpec(1.0));
// now set up and transfer relevant information
// first the clustering sequence
transfer_from_sequence(csva);
// then the areas
_resize_and_zero_AA();
for (unsigned i = 0; i < _history.size(); i++) {
int ijetp = _history[i].jetp_index;
if (ijetp != Invalid) {
_average_area[i] = csva.area(_jets[ijetp]);
_average_area_4vector[i] = csva.area_4vector(_jets[ijetp]);
}
}
} else if (jet_def_in.jet_algorithm() == cambridge_algorithm) {
// run a variant of the cambridge algorithm that has been hacked
// to deal with passive areas
JetDefinition tmp_jet_def = jet_def_in;
tmp_jet_def.set_jet_finder(cambridge_for_passive_algorithm);
tmp_jet_def.set_extra_param(sqrt(area_spec.mean_ghost_kt()));
_initialise_and_run_AA(tmp_jet_def, area_spec, writeout_combinations);
_jet_def = jet_def_in;
} else if (jet_def_in.jet_algorithm() == antikt_algorithm) {
// for the antikt algorithm, passive and active are identical
_initialise_and_run_AA(jet_def_in, area_spec, writeout_combinations);
} else if (jet_def_in.jet_algorithm() == plugin_algorithm &&
jet_def_in.plugin()->supports_ghosted_passive_areas()) {
// for some plugin algorithms, one can "prime" the algorithm with information
// about the ghost scale, and then an "AA" run will actually give a passive
// area
double ghost_sep_scale_store = jet_def_in.plugin()->ghost_separation_scale();
jet_def_in.plugin()->set_ghost_separation_scale(sqrt(area_spec.mean_ghost_kt()));
_initialise_and_run_AA(jet_def_in, area_spec, writeout_combinations);
// restore the original ghost_sep_scale
jet_def_in.plugin()->set_ghost_separation_scale(ghost_sep_scale_store);
} else {
// for a generic algorithm, just run the 1GhostPassiveArea
_initialise_and_run_1GPA(jet_def_in, area_spec, writeout_combinations);
}
}
//----------------------------------------------------------------------
// dispatch to most relevant empty area calculation...
double ClusterSequencePassiveArea::empty_area (const Selector & selector) const {
if (jet_def().jet_algorithm() == kt_algorithm) {
// run the naive algorithm
return ClusterSequenceAreaBase::empty_area(selector);
} else {
return ClusterSequence1GhostPassiveArea::empty_area(selector);
}
}
FASTJET_END_NAMESPACE // defined in fastjet/internal/base.hh
fastjet::ClusterSequenceActiveArea::empty_area
virtual double empty_area(const Selector &selector) const override
rewrite the empty area from the parent class, so as to use all info at our disposal return the total ...
Definition ClusterSequenceActiveArea.cc:445
fastjet::ClusterSequenceAreaBase::empty_area
virtual double empty_area(const Selector &selector) const
return the total area, corresponding to the given Selector, that is free of jets, in general based on...
Definition ClusterSequenceAreaBase.cc:57
fastjet::ClusterSequencePassiveArea::empty_area
virtual double empty_area(const Selector &selector) const override
return an empty area that's appropriate to the passive area determination carried out
Definition ClusterSequencePassiveArea.cc:97
fastjet::ClusterSequence::jet_def
const JetDefinition & jet_def() const
return a reference to the jet definition
Definition ClusterSequence.hh:283
fastjet::Selector
Class that encodes information about cuts and other selection criteria that can be applied to PseudoJ...
Definition Selector.hh:149
fastjet::kt_algorithm
@ kt_algorithm
the longitudinally invariant kt algorithm
Definition JetDefinition.hh:139