1 //FJSTARTHEADER
2 // $Id: Dnn4piCylinder.hh 4442 2020-05-05 07:50:11Z soyez $
3 //
4 // Copyright (c) 2005-2020, 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
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14 // The algorithms that underlie FastJet have required considerable
15 // development. They are described in the original FastJet paper,
16 // hep-ph/0512210 and in the manual, arXiv:1111.6097. If you use
17 // FastJet as part of work towards a scientific publication, please
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24 // GNU General Public License for more details.
25 //
26 // You should have received a copy of the GNU General Public License
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28 //----------------------------------------------------------------------
29 //FJENDHEADER
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
Dnn4piCylinder()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.
_remap_phi(const EtaPhi & point)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
NearestNeighbourIndex(const int current) const102 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
NearestNeighbourDistance(const int current) const109 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
Valid(const int index) const116 inline bool Dnn4piCylinder::Valid(const int index) const {
117 return (_DNN1->Valid(index) && _DNN2->Valid(index));
118 }
119
120
~Dnn4piCylinder()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
131