nearest_neighbor_sort.hpp
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1 
13 #ifndef MLPACK_METHODS_NEIGHBOR_SEARCH_NEAREST_NEIGHBOR_SORT_HPP
14 #define MLPACK_METHODS_NEIGHBOR_SEARCH_NEAREST_NEIGHBOR_SORT_HPP
15 
16 #include <mlpack/prereqs.hpp>
17 
18 namespace mlpack {
19 namespace neighbor {
20 
31 class NearestNS
32 {
33  public:
43  static inline bool IsBetter(const double value, const double ref)
44  {
45  return (value <= ref);
46  }
47 
53  template<typename TreeType>
54  static double BestNodeToNodeDistance(const TreeType* queryNode,
55  const TreeType* referenceNode);
56 
63  template<typename TreeType>
64  static double BestNodeToNodeDistance(const TreeType* queryNode,
65  const TreeType* referenceNode,
66  const double centerToCenterDistance);
67 
80  template<typename TreeType>
81  static double BestNodeToNodeDistance(const TreeType* queryNode,
82  const TreeType* referenceNode,
83  const TreeType* referenceChildNode,
84  const double centerToCenterDistance);
85 
91  template<typename VecType, typename TreeType>
92  static double BestPointToNodeDistance(const VecType& queryPoint,
93  const TreeType* referenceNode);
94 
101  template<typename VecType, typename TreeType>
102  static double BestPointToNodeDistance(const VecType& queryPoint,
103  const TreeType* referenceNode,
104  const double pointToCenterDistance);
105 
110  template<typename VecType, typename TreeType>
111  static size_t GetBestChild(const VecType& queryPoint, TreeType& referenceNode)
112  {
113  return referenceNode.GetNearestChild(queryPoint);
114  };
115 
120  template<typename TreeType>
121  static size_t GetBestChild(const TreeType& queryNode, TreeType& referenceNode)
122  {
123  return referenceNode.GetNearestChild(queryNode);
124  };
125 
133  static inline double WorstDistance() { return DBL_MAX; }
134 
142  static inline double BestDistance() { return 0.0; }
143 
147  static inline double CombineBest(const double a, const double b)
148  {
149  return std::max(a - b, 0.0);
150  }
151 
155  static inline double CombineWorst(const double a, const double b)
156  {
157  if (a == DBL_MAX || b == DBL_MAX)
158  return DBL_MAX;
159  return a + b;
160  }
161 
170  static inline double Relax(const double value, const double epsilon)
171  {
172  if (value == DBL_MAX)
173  return DBL_MAX;
174  return (1 / (1 + epsilon)) * value;
175  }
176 
182  static inline double ConvertToScore(const double distance)
183  {
184  return distance;
185  }
186 
192  static inline double ConvertToDistance(const double score)
193  {
194  return score;
195  }
196 };
197 
198 // Due to an internal MinGW compiler bug (string table overflow) we have to
199 // truncate the class name. For backward compatibility we setup an alias here.
201 
202 } // namespace neighbor
203 } // namespace mlpack
204 
205 // Include implementation of templated functions.
206 #include "nearest_neighbor_sort_impl.hpp"
207 
208 #endif
static double CombineWorst(const double a, const double b)
Return the worst combination of the two distances.
static double ConvertToDistance(const double score)
Convert the given score to a distance.
.hpp
Definition: add_to_po.hpp:21
The core includes that mlpack expects; standard C++ includes and Armadillo.
static double ConvertToScore(const double distance)
Convert the given distance into a score.
static size_t GetBestChild(const VecType &queryPoint, TreeType &referenceNode)
Return the best child according to this sort policy.
static double BestPointToNodeDistance(const VecType &queryPoint, const TreeType *referenceNode)
Return the best possible distance between a node and a point.
static bool IsBetter(const double value, const double ref)
Return whether or not value is "better" than ref.
static double WorstDistance()
Return what should represent the worst possible distance with this particular sort policy...
This class implements the necessary methods for the SortPolicy template parameter of the NeighborSear...
static double BestNodeToNodeDistance(const TreeType *queryNode, const TreeType *referenceNode)
Return the best possible distance between two nodes.
static double Relax(const double value, const double epsilon)
Return the given value relaxed.
static double BestDistance()
Return what should represent the best possible distance with this particular sort policy...
static size_t GetBestChild(const TreeType &queryNode, TreeType &referenceNode)
Return the best child according to this sort policy.
static double CombineBest(const double a, const double b)
Return the best combination of the two distances.