HaltonSequence.cpp
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34 
35 /* Author: Leonard Bruns */
36 
37 #include "ompl/base/samplers/deterministic/HaltonSequence.h"
38 #include "ompl/util/Console.h"
39 #include <iostream>
40 #include <cmath>
41 #include <map>
42 #include <boost/math/special_functions/prime.hpp>
43 
44 namespace ompl
45 {
46  namespace base
47  {
48  HaltonSequence1D::HaltonSequence1D() : i_(1), base_(2)
49  {
50  }
51 
52  HaltonSequence1D::HaltonSequence1D(unsigned int base) : i_(1), base_(base)
53  {
54  }
55 
56  void HaltonSequence1D::setBase(unsigned int base)
57  {
58  base_ = base;
59  }
60 
62  {
63  double f = 1, r = 0;
64  unsigned int i = i_;
65 
66  while (i > 0)
67  {
68  f /= base_;
69  r += f * (i % base_);
70  i = std::floor(i / base_);
71  }
72 
73  ++i_;
74  return r;
75  }
76 
77  HaltonSequence::HaltonSequence(unsigned int dimensions)
78  : DeterministicSequence(dimensions), halton_sequences_1d_(dimensions)
79  {
80  setBasesToPrimes();
81  }
82 
83  HaltonSequence::HaltonSequence(unsigned int dimensions, std::vector<unsigned int> bases)
84  : DeterministicSequence(dimensions), halton_sequences_1d_(dimensions)
85  {
86  if (bases.size() != dimensions)
87  {
88  OMPL_WARN("Number of bases does not match dimensions. Using first n primes instead.");
89  }
90  else
91  {
92  int i = 0;
93  for (auto base : bases)
94  {
95  halton_sequences_1d_[i].setBase(base);
96  i++;
97  }
98  }
99  }
100 
101  std::vector<double> HaltonSequence::sample()
102  {
103  std::vector<double> samples;
104  for (auto &seq : halton_sequences_1d_)
105  {
106  samples.push_back(seq.sample());
107  }
108  return samples;
109  }
110 
111  void HaltonSequence::setBasesToPrimes()
112  {
113  // set the base of the halton sequences to the first n prime numbers, where n is dimensions
114  unsigned int current = 2;
115  for (unsigned int i = 0; i < dimensions_; i++)
116  {
117  current = boost::math::prime(i);
118  halton_sequences_1d_[i].setBase(current);
119  }
120  }
121  } // namespace base
122 } // namespace ompl
double sample()
Returns the next sample in the interval [0,1].
std::vector< double > sample() override
Returns the next sample in the interval [0,1].
HaltonSequence(unsigned int dimensions)
Constructor, only specifiying the dimensions, first n primes will be used as bases.
#define OMPL_WARN(fmt,...)
Log a formatted warning string.
Definition: Console.h:66
void setBase(unsigned int base)
Sets the base of the halton sequence.
Main namespace. Contains everything in this library.
Definition: AppBase.h:22