1 //FJSTARTHEADER
2 // $Id: ClusterSequence1GhostPassiveArea.cc 4442 2020-05-05 07:50:11Z soyez $
3 //
4 // Copyright (c) 2005-2020, Matteo Cacciari, Gavin P. Salam and Gregory Soyez
5 //
6 //----------------------------------------------------------------------
7 // This file is part of FastJet.
8 //
9 // FastJet is free software; you can redistribute it and/or modify
10 // it under the terms of the GNU General Public License as published by
11 // the Free Software Foundation; either version 2 of the License, or
12 // (at your option) any later version.
13 //
14 // The algorithms that underlie FastJet have required considerable
15 // development. They are described in the original FastJet paper,
16 // hep-ph/0512210 and in the manual, arXiv:1111.6097. If you use
17 // FastJet as part of work towards a scientific publication, please
18 // quote the version you use and include a citation to the manual and
19 // optionally also to hep-ph/0512210.
20 //
21 // FastJet is distributed in the hope that it will be useful,
22 // but WITHOUT ANY WARRANTY; without even the implied warranty of
23 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 // GNU General Public License for more details.
25 //
26 // You should have received a copy of the GNU General Public License
27 // along with FastJet. If not, see <http://www.gnu.org/licenses/>.
28 //----------------------------------------------------------------------
29 //FJENDHEADER
30
31 #include "fastjet/ClusterSequence1GhostPassiveArea.hh"
32
33 FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
34
35
36 using namespace std;
37
38 //----------------------------------------------------------------------
39 /// global routine for initialising and running a general passive area
_initialise_and_run_1GPA(const JetDefinition & jet_def_in,const GhostedAreaSpec & area_spec,const bool & writeout_combinations)40 void ClusterSequence1GhostPassiveArea::_initialise_and_run_1GPA (
41 const JetDefinition & jet_def_in,
42 const GhostedAreaSpec & area_spec,
43 const bool & writeout_combinations) {
44
45 bool continue_running;
46 _initialise_AA(jet_def_in, area_spec, writeout_combinations, continue_running);
47 if (continue_running) {
48 _run_1GPA(area_spec);
49 _postprocess_AA(area_spec);
50 }
51 }
52
53
54 //----------------------------------------------------------------------
55 /// routine for running a passive area one ghost at a time.
_run_1GPA(const GhostedAreaSpec & area_spec)56 void ClusterSequence1GhostPassiveArea::_run_1GPA (const GhostedAreaSpec & area_spec) {
57 // record the input jets as they are currently
58 vector<PseudoJet> input_jets(_jets);
59
60 // code for testing the unique tree
61 vector<int> unique_tree;
62
63 // initialise our temporary average area^2
64 valarray<double> lcl_average_area2(0.0, _average_area.size());
65 valarray<double> last_average_area(0.0, _average_area.size());
66
67 // run the clustering multiple times so as to get areas of all the jets
68 for (int irepeat = 0; irepeat < area_spec.repeat(); irepeat++) {
69
70 // first establish list of all ghosts
71 vector<PseudoJet> all_ghosts;
72 area_spec.add_ghosts(all_ghosts);
73
74 // then run many subsets of ghosts (actually each subset contains just one ghost)
75 for (unsigned ig = 0; ig < all_ghosts.size(); ig++) {
76 vector<PseudoJet> some_ghosts;
77 some_ghosts.push_back(all_ghosts[ig]);
78 ClusterSequenceActiveAreaExplicitGhosts clust_seq(input_jets, jet_def(),
79 some_ghosts, area_spec.actual_ghost_area());
80
81 if (irepeat == 0 && ig == 0) {
82 // take the non-ghost part of the history and put into our own
83 // history.
84 _transfer_ghost_free_history(clust_seq);
85 // get the "unique" order that will be used for transferring all areas.
86 unique_tree = unique_history_order();
87 }
88
89 // transfer areas from clust_seq into our object
90 _transfer_areas(unique_tree, clust_seq);
91 }
92 // keep track of fluctuations in area
93 lcl_average_area2 += (_average_area - last_average_area)*
94 (_average_area - last_average_area);
95 last_average_area = _average_area;
96 }
97 _average_area2 = lcl_average_area2;
98 }
99
100
101 FASTJET_END_NAMESPACE // defined in fastjet/internal/base.hh
102
103