FastJet  3.3.2
ClusterSequence1GhostPassiveArea.cc
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2 // $Id: ClusterSequence1GhostPassiveArea.cc 4354 2018-04-22 07:12:37Z salam $
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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
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.
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 
void add_ghosts(std::vector< PseudoJet > &) const
push a set of ghost 4-momenta onto the back of the vector of PseudoJets
Like ClusterSequence with computation of the active jet area with the addition of explicit ghosts...
Parameters to configure the computation of jet areas using ghosts.
class that is intended to hold a full definition of the jet clusterer