FastJet  3.0.6
Dnn3piCylinder.cc
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2 // $Id: Dnn3piCylinder.cc 2577 2011-09-13 15:11:38Z salam $
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28 
29 
30 #ifndef DROP_CGAL // in case we do not have the code for CGAL
31 #include <set>
32 #include "fastjet/internal/Dnn3piCylinder.hh"
33 using namespace std;
34 
35 FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
36 
37 //----------------------------------------------------------------------
38 /// initialiser...
39 Dnn3piCylinder::Dnn3piCylinder(
40  const vector<EtaPhi> & input_points,
41  const bool & ignore_nearest_is_mirror,
42  const bool & verbose) {
43 
44  _verbose = verbose;
45  _ignore_nearest_is_mirror = ignore_nearest_is_mirror;
46  vector<EtaPhi> plane_points;
47  //plane_points.reserve(2*input_points.size());
48 
49  for (unsigned int i=0; i < input_points.size(); i++) {
50  _RegisterCylinderPoint(input_points[i], plane_points);
51  }
52 
53  if (_verbose) cout << "============== Preparing _DNN" << endl;
54  _DNN = new DnnPlane(plane_points, verbose);
55 }
56 
57 
58 //----------------------------------------------------------------------
59 /// What on earth does this do?
60 ///
61 /// Example: last true "cylinder" index was 15
62 /// last plane index was 23
63 ///
64 /// Then: _cylinder_index_of_plane_vertex.size() = 24 and
65 /// _mirror_info.size() = 16
66 ///
67 /// IF cylinder_point's phi < pi then
68 /// create: _mirror_info[16] = (main_index = 24, mirror_index=25)
69 /// _cylinder_index_of_plane_vertex[24] = 16
70 /// _cylinder_index_of_plane_vertex[25] = 16
71 /// ELSE
72 /// create: _mirror_info[16] = (main_index = 24, mirror_index=INEXISTENT..)
73 /// _cylinder_index_of_plane_vertex[24] = 16
74 ///
75 /// ADDITIONALLY push the cylinder_point (and if it exists the mirror
76 /// copy) onto the vector plane_points.
77 void Dnn3piCylinder::_RegisterCylinderPoint (const EtaPhi & cylinder_point,
78  vector<EtaPhi> & plane_points) {
79  double phi = cylinder_point.second;
80  assert(phi >= 0.0 && phi < 2*pi);
81 
82  // do main point
83  MirrorVertexInfo mvi;
84  mvi.main_index = _cylinder_index_of_plane_vertex.size();
85  _cylinder_index_of_plane_vertex.push_back(_mirror_info.size());
86  plane_points.push_back(cylinder_point);
87 
88  // do mirror point if need be
89  if (phi < pi) {
90  mvi.mirror_index = _cylinder_index_of_plane_vertex.size();
91  _cylinder_index_of_plane_vertex.push_back(_mirror_info.size());
92  plane_points.push_back(_remap_phi(cylinder_point));
93  } else {
94  mvi.mirror_index = INEXISTENT_VERTEX;
95  }
96 
97  //
98  _mirror_info.push_back(mvi);
99 }
100 
101 
102 //----------------------------------------------------------------------
103 /// insertion and removal of points
104 void Dnn3piCylinder::RemoveAndAddPoints(const vector<int> & indices_to_remove,
105  const vector<EtaPhi> & points_to_add,
106  vector<int> & indices_added,
107  vector<int> & indices_of_updated_neighbours) {
108 
109  // translate from "cylinder" indices of points to remove to the
110  // plane indices of points to remove, bearing in mind that sometimes
111  // there are multple plane points to remove.
112  vector<int> plane_indices_to_remove;
113  for (unsigned int i=0; i < indices_to_remove.size(); i++) {
114  MirrorVertexInfo * mvi;
115  mvi = & _mirror_info[indices_to_remove[i]];
116  plane_indices_to_remove.push_back(mvi->main_index);
117  if (mvi->mirror_index != INEXISTENT_VERTEX) {
118  plane_indices_to_remove.push_back(mvi->mirror_index);
119  }
120  }
121 
122  // given "cylinder" points to add get hold of the list of
123  // plane-points to add.
124  vector<EtaPhi> plane_points_to_add;
125  indices_added.clear();
126  for (unsigned int i=0; i < points_to_add.size(); i++) {
127  indices_added.push_back(_mirror_info.size());
128  _RegisterCylinderPoint(points_to_add[i], plane_points_to_add);
129  }
130 
131  // now get the hard work done (note that we need to supply the
132  // plane_indices_added vector but that we will not actually check
133  // its contents in any way -- the indices_added that is actually
134  // returned has been calculated above).
135  vector<int> updated_plane_neighbours, plane_indices_added;
136  _DNN->RemoveAndAddPoints(plane_indices_to_remove, plane_points_to_add,
137  plane_indices_added, updated_plane_neighbours);
138 
139  // extract, from the updated_plane_neighbours, the set of cylinder
140  // neighbours that have changed
141  set<int> index_set;
142  unsigned int i;
143  for (i=0; i < updated_plane_neighbours.size(); i++) {
144  index_set.insert(
145  _cylinder_index_of_plane_vertex[updated_plane_neighbours[i]]);}
146 
147  // decant the set into the vector that needs to be returned
148  indices_of_updated_neighbours.clear();
149  for (set<int>::iterator iter = index_set.begin();
150  iter != index_set.end(); iter++) {
151  indices_of_updated_neighbours.push_back(*iter);
152  }
153 }
154 
155 
156 FASTJET_END_NAMESPACE
157 
158 #endif // DROP_CGAL
159