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:
60  NearestNeighborsSqrtApprox() = default;
61 
62  ~NearestNeighborsSqrtApprox() override = default;
63 
64  void clear() override
65  {
67  checks_ = 0;
68  offset_ = 0;
69  }
70 
71  void add(const _T &data) override
72  {
75  }
76 
77  void add(const std::vector<_T> &data) override
78  {
81  }
82 
83  bool remove(const _T &data) override
84  {
85  bool result = NearestNeighborsLinear<_T>::remove(data);
86  if (result)
88  return result;
89  }
90 
91  _T nearest(const _T &data) const override
92  {
93  const std::size_t n = NearestNeighborsLinear<_T>::data_.size();
94  std::size_t pos = n;
95 
96  if (checks_ > 0 && n > 0)
97  {
98  double dmin = 0.0;
99  for (std::size_t j = 0; j < checks_; ++j)
100  {
101  std::size_t i = (j * checks_ + offset_) % n;
102 
104  if (pos == n || dmin > distance)
105  {
106  pos = i;
107  dmin = distance;
108  }
109  }
110  offset_ = (offset_ + 1) % checks_;
111  }
112  if (pos != n)
114 
115  throw Exception("No elements found in nearest neighbors data structure");
116  }
117 
118  protected:
120  inline void updateCheckCount()
121  {
122  checks_ = 1 + (std::size_t)floor(sqrt((double)NearestNeighborsLinear<_T>::data_.size()));
123  }
124 
126  std::size_t checks_{0};
127 
129  mutable std::size_t offset_{0};
130  };
131 }
132 
133 #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