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ClusterSequence1GhostPassiveArea.cc
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2 // $Id: ClusterSequence1GhostPassiveArea.cc 2687 2011-11-14 11:17:51Z soyez $
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4 // Copyright (c) 2005-2011, Matteo Cacciari, Gavin P. Salam and Gregory Soyez
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28 
29 #include "fastjet/ClusterSequence1GhostPassiveArea.hh"
30 
31 FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
32 
33 
34 using namespace std;
35 
36 //----------------------------------------------------------------------
37 /// global routine for initialising and running a general passive area
38 void ClusterSequence1GhostPassiveArea::_initialise_and_run_1GPA (
39  const JetDefinition & jet_def_in,
40  const GhostedAreaSpec & area_spec,
41  const bool & writeout_combinations) {
42 
43  bool continue_running;
44  _initialise_AA(jet_def_in, area_spec, writeout_combinations, continue_running);
45  if (continue_running) {
46  _run_1GPA(area_spec);
47  _postprocess_AA(area_spec);
48  }
49 }
50 
51 
52 //----------------------------------------------------------------------
53 /// routine for running a passive area one ghost at a time.
54 void ClusterSequence1GhostPassiveArea::_run_1GPA (const GhostedAreaSpec & area_spec) {
55  // record the input jets as they are currently
56  vector<PseudoJet> input_jets(_jets);
57 
58  // code for testing the unique tree
59  vector<int> unique_tree;
60 
61  // initialise our temporary average area^2
62  valarray<double> lcl_average_area2(0.0, _average_area.size());
63  valarray<double> last_average_area(0.0, _average_area.size());
64 
65  // run the clustering multiple times so as to get areas of all the jets
66  for (int irepeat = 0; irepeat < area_spec.repeat(); irepeat++) {
67 
68  // first establish list of all ghosts
69  vector<PseudoJet> all_ghosts;
70  area_spec.add_ghosts(all_ghosts);
71 
72  // then run many subsets of ghosts (actually each subset contains just one ghost)
73  for (unsigned ig = 0; ig < all_ghosts.size(); ig++) {
74  vector<PseudoJet> some_ghosts;
75  some_ghosts.push_back(all_ghosts[ig]);
76  ClusterSequenceActiveAreaExplicitGhosts clust_seq(input_jets, jet_def(),
77  some_ghosts, area_spec.actual_ghost_area());
78 
79  if (irepeat == 0 && ig == 0) {
80  // take the non-ghost part of the history and put into our own
81  // history.
82  _transfer_ghost_free_history(clust_seq);
83  // get the "unique" order that will be used for transferring all areas.
84  unique_tree = unique_history_order();
85  }
86 
87  // transfer areas from clust_seq into our object
88  _transfer_areas(unique_tree, clust_seq);
89  }
90  // keep track of fluctuations in area
91  lcl_average_area2 += (_average_area - last_average_area)*
92  (_average_area - last_average_area);
93  last_average_area = _average_area;
94  }
95  _average_area2 = lcl_average_area2;
96 }
97 
98 
99 FASTJET_END_NAMESPACE // defined in fastjet/internal/base.hh
100