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