FastJet  3.0.3
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Groups Pages
Dnn4piCylinder.hh
1 //STARTHEADER
2 // $Id: Dnn4piCylinder.hh 2577 2011-09-13 15:11:38Z salam $
3 //
4 // Copyright (c) 2005-2011, 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 
30 #ifndef DROP_CGAL // in case we do not have the code for CGAL
31 #ifndef __FASTJET_DNN4PICYLINDER_HH__
32 #define __FASTJET_DNN4PICYLINDER_HH__
33 
34 #include "fastjet/internal/DynamicNearestNeighbours.hh"
35 #include "fastjet/internal/DnnPlane.hh"
36 #include "fastjet/internal/numconsts.hh"
37 
38 FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
39 
40 /// \if internal_doc
41 /// @ingroup internal
42 /// \class Dnn4piCylinder
43 /// class derived from DynamicNearestNeighbours that provides an
44 /// implementation for the surface of cylinder (using two copies of
45 /// DnnPlane, one running from 0--2pi, the other from pi--3pi).
46 /// \endif
47 class Dnn4piCylinder : public DynamicNearestNeighbours {
48  public:
49  /// empty initaliser
50  Dnn4piCylinder() {}
51 
52  /// Initialiser from a set of points on an Eta-Phi plane, where
53  /// eta can have an arbitrary ranges and phi must be in range
54  /// 0 <= phi < 2pi
55  Dnn4piCylinder(const std::vector<EtaPhi> &, const bool & verbose = false );
56 
57  /// Returns the index of the nearest neighbour of point labelled
58  /// by ii (assumes ii is valid)
59  int NearestNeighbourIndex(const int & ii) const ;
60 
61  /// Returns the distance to the nearest neighbour of point labelled
62  /// by index ii (assumes ii is valid)
63  double NearestNeighbourDistance(const int & ii) const ;
64 
65  /// Returns true iff the given index corresponds to a point that
66  /// exists in the DNN structure (meaning that it has been added, and
67  /// not removed in the meantime)
68  bool Valid(const int & index) const;
69 
70  void RemoveAndAddPoints(const std::vector<int> & indices_to_remove,
71  const std::vector<EtaPhi> & points_to_add,
72  std::vector<int> & indices_added,
73  std::vector<int> & indices_of_updated_neighbours);
74 
75  ~Dnn4piCylinder();
76 
77  private:
78 
79  bool _verbose;
80 
81  // NB: we define POINTERS here because the initialisation gave
82  // us problems (things crashed!), perhaps because in practice
83  // we were making a copy without being careful and defining
84  // a proper copy constructor.
85  DnnPlane * _DNN1, * _DNN2;
86 
87  /// given a phi value in the 0--2pi range return one
88  /// in the pi--3pi range.
89  inline EtaPhi _remap_phi(const EtaPhi & point) {
90  double phi = point.second;
91  if (phi < pi) { phi += twopi ;}
92  return EtaPhi(point.first, phi);}
93 
94 };
95 
96 
97 // here follow some inline implementations of the simpler of the
98 // functions defined above
99 
100 inline int Dnn4piCylinder::NearestNeighbourIndex(const int & current) const {
101  return (_DNN1->NearestNeighbourDistance(current) <
102  _DNN2->NearestNeighbourDistance(current)) ?
103  _DNN1->NearestNeighbourIndex(current) :
104  _DNN2->NearestNeighbourIndex(current) ;
105 }
106 
107 inline double Dnn4piCylinder::NearestNeighbourDistance(const int & current) const {
108  return (_DNN1->NearestNeighbourDistance(current) <
109  _DNN2->NearestNeighbourDistance(current)) ?
110  _DNN1->NearestNeighbourDistance(current) :
111  _DNN2->NearestNeighbourDistance(current) ;
112 }
113 
114 inline bool Dnn4piCylinder::Valid(const int & index) const {
115  return (_DNN1->Valid(index) && _DNN2->Valid(index));
116 }
117 
118 
119 inline Dnn4piCylinder::~Dnn4piCylinder() {
120  delete _DNN1;
121  delete _DNN2;
122 }
123 
124 
125 FASTJET_END_NAMESPACE
126 
127 #endif // __FASTJET_DNN4PICYLINDER_HH__
128 #endif // DROP_CGAL