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source: svn/trunk/external/fastjet/plugins/NestedDefs/NestedDefsPlugin.cc

Last change on this file was 859, checked in by Pavel Demin, 12 years ago

update fastjet to version 3.0.3

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id Revision Date
File size: 5.0 KB
Line 
1//STARTHEADER
2// $Id: NestedDefsPlugin.cc 859 2012-11-28 01:49:23Z pavel $
3//
4// Copyright (c) 2007-2011, 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 and are described in hep-ph/0512210. If you use
16// FastJet as part of work towards a scientific publication, please
17// include a citation to the FastJet paper.
18//
19// FastJet is distributed in the hope that it will be useful,
20// but WITHOUT ANY WARRANTY; without even the implied warranty of
21// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22// GNU General Public License for more details.
23//
24// You should have received a copy of the GNU General Public License
25// along with FastJet. If not, see <http://www.gnu.org/licenses/>.
26//----------------------------------------------------------------------
27//ENDHEADER
28
29// TODO
30// ? Maybe one could provide additional recomb. dists as an "extra".;
31
32// fastjet stuff
33#include "fastjet/ClusterSequence.hh"
34#include "fastjet/NestedDefsPlugin.hh"
35
36// other stuff
37#include <vector>
38#include <sstream>
39
40FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
41
42using namespace std;
43
44string NestedDefsPlugin::description () const {
45 ostringstream desc;
46
47 desc << "NestedDefs: successive application of " ;
48 unsigned int i=1;
49 for (list<JetDefinition>::const_iterator it=_defs.begin();it!=_defs.end();it++){
50 desc << "Definition " << i++ << " [" << it->description() << "] - ";
51 }
52
53 return desc.str();
54}
55
56void NestedDefsPlugin::run_clustering(ClusterSequence & clust_seq) const {
57 vector<PseudoJet> momenta;
58
59 // build the initial list of particles
60 momenta = clust_seq.jets();
61 unsigned int step_n = momenta.size();
62
63 // initialise the conversion table, which works as follows
64 // conversion_table[step_cs_jet_index] = main_cs_jet_index
65 vector<unsigned int> conversion_table(2*step_n);
66 vector<unsigned int> new_conversion_table;
67 for (unsigned int i=0;i<step_n;i++)
68 conversion_table[i]=i;
69
70 // Now the steps go as follows:
71 // for each definition in the list,
72 // - do the clustering,
73 // - copy the history into the main one
74 // - update the list of momenta and the index conversion table
75 list<JetDefinition>::const_iterator def_iterator = _defs.begin();
76 unsigned int def_index=0;
77 bool last_def=false;
78
79 while (def_iterator!=_defs.end()){
80 last_def = (def_index == (_defs.size()-1));
81
82 // do the clustering
83 ClusterSequence step_cs(momenta, *def_iterator);
84
85 // clear the momenta as we shall fill them again
86 momenta.clear();
87 new_conversion_table.clear();
88
89 // retrieve the history
90 const vector<ClusterSequence::history_element> & step_history = step_cs.history();
91
92 // copy the history
93 // note that we skip the initial steps which are just the
94 // declaration of the particles.
95 vector<ClusterSequence::history_element>::const_iterator
96 hist_iterator = step_history.begin();
97
98 for (unsigned int i=step_n;i!=0;i--)
99 hist_iterator++;
100
101 while (hist_iterator != step_history.end()){
102 // check if it is a recombination with the beam or a simple recombination
103 if (hist_iterator->parent2 == ClusterSequence::BeamJet){
104 // save this jet for future clustering
105 // unless we've reached the last def in which case, record the clustering
106 unsigned int step_jet_index = step_cs.history()[hist_iterator->parent1].jetp_index;
107 if (last_def){
108 clust_seq.plugin_record_iB_recombination(conversion_table[step_jet_index],
109 hist_iterator->dij);
110 } else {
111 momenta.push_back(step_cs.jets()[step_jet_index]);
112 new_conversion_table.push_back(conversion_table[step_jet_index]);
113 }
114 } else {
115 // record combination
116 // note that we set the recombination distance to 0 except for the last alg
117 unsigned int step_jet1_index = step_cs.history()[hist_iterator->parent1].jetp_index;
118 unsigned int step_jet2_index = step_cs.history()[hist_iterator->parent2].jetp_index;
119 PseudoJet newjet = step_cs.jets()[hist_iterator->jetp_index];
120 int jet_k;
121 clust_seq.plugin_record_ij_recombination(conversion_table[step_jet1_index],
122 conversion_table[step_jet2_index],
123 last_def ? hist_iterator->dij : 0.0,
124 newjet, jet_k);
125
126 // save info in the conversion table for tracking purposes
127 conversion_table[hist_iterator->jetp_index]=jet_k;
128 }
129
130 // go to the next history element
131 hist_iterator++;
132 }
133
134 // finalise this step:
135 // - update nr of particles
136 // - update conversion table
137 step_n = momenta.size();
138 for (unsigned int i=0;i<step_n;i++)
139 conversion_table[i] = new_conversion_table[i];
140
141 // go to the next alg
142 def_index++;
143 def_iterator++;
144 }
145
146}
147
148FASTJET_END_NAMESPACE // defined in fastjet/internal/base.hh
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