NearestNeighborsSqrtApprox.h
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34 
35 /* Author: Ioan Sucan */
36 
37 #ifndef OMPL_DATASTRUCTURES_NEAREST_NEIGHBORS_SQRT_APPROX_
38 #define OMPL_DATASTRUCTURES_NEAREST_NEIGHBORS_SQRT_APPROX_
39 
40 #include "ompl/datastructures/NearestNeighborsLinear.h"
41 #include <algorithm>
42 #include <cmath>
43 
44 namespace ompl
45 {
56  template <typename _T>
58  {
59  public:
61  {
62  }
63 
64  ~NearestNeighborsSqrtApprox() override = default;
65 
66  void clear() override
67  {
69  checks_ = 0;
70  offset_ = 0;
71  }
72 
73  void add(const _T &data) override
74  {
77  }
78 
79  void add(const std::vector<_T> &data) override
80  {
83  }
84 
85  bool remove(const _T &data) override
86  {
87  bool result = NearestNeighborsLinear<_T>::remove(data);
88  if (result)
90  return result;
91  }
92 
93  _T nearest(const _T &data) const override
94  {
95  const std::size_t n = NearestNeighborsLinear<_T>::data_.size();
96  std::size_t pos = n;
97 
98  if (checks_ > 0 && n > 0)
99  {
100  double dmin = 0.0;
101  for (std::size_t j = 0; j < checks_; ++j)
102  {
103  std::size_t i = (j * checks_ + offset_) % n;
104 
106  if (pos == n || dmin > distance)
107  {
108  pos = i;
109  dmin = distance;
110  }
111  }
112  offset_ = (offset_ + 1) % checks_;
113  }
114  if (pos != n)
116 
117  throw Exception("No elements found in nearest neighbors data structure");
118  }
119 
120  protected:
122  inline void updateCheckCount()
123  {
124  checks_ = 1 + (std::size_t)floor(sqrt((double)NearestNeighborsLinear<_T>::data_.size()));
125  }
126 
128  std::size_t checks_;
129 
131  mutable std::size_t offset_;
132  };
133 }
134 
135 #endif
void updateCheckCount()
The maximum number of checks to perform when searching for a nearest neighbor.
std::size_t offset_
The offset to start checking at (between 0 and checks_)
_T nearest(const _T &data) const override
Get the nearest neighbor of a point.
std::size_t checks_
The number of checks to be performed when looking for a nearest neighbor.
void add(const _T &data) override
Add an element to the datastructure.
Main namespace. Contains everything in this library.
Definition: AppBase.h:21
A nearest neighbors datastructure that uses linear search. The linear search is done over sqrt(n) ele...
bool remove(const _T &data) override
Remove an element from the datastructure.
void add(const _T &data) override
Add an element to the datastructure.
void clear() override
Clear the datastructure.
void clear() override
Clear the datastructure.
A nearest neighbors datastructure that uses linear search.
std::size_t size() const override
Get the number of elements in the datastructure.
DistanceFunction distFun_
The used distance function.
void add(const std::vector< _T > &data) override
Add a vector of points.
The exception type for ompl.
Definition: Exception.h:46