random.h
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30 
31 #ifndef OPENCV_FLANN_RANDOM_H
32 #define OPENCV_FLANN_RANDOM_H
33 
34 #include <algorithm>
35 #include <cstdlib>
36 #include <vector>
37 
38 #include "general.h"
39 
40 namespace cvflann
41 {
42 
47 inline void seed_random(unsigned int seed)
48 {
49  srand(seed);
50 }
51 
52 /*
53  * Generates a random double value.
54  */
61 inline double rand_double(double high = 1.0, double low = 0)
62 {
63  return low + ((high-low) * (std::rand() / (RAND_MAX + 1.0)));
64 }
65 
72 inline int rand_int(int high = RAND_MAX, int low = 0)
73 {
74  return low + (int) ( double(high-low) * (std::rand() / (RAND_MAX + 1.0)));
75 }
76 
82 {
83  std::vector<int> vals_;
84  int size_;
85  int counter_;
86 
87 public:
94  {
95  init(n);
96  }
97 
102  void init(int n)
103  {
104  // create and initialize an array of size n
105  vals_.resize(n);
106  size_ = n;
107  for (int i = 0; i < size_; ++i) vals_[i] = i;
108 
109  // shuffle the elements in the array
110  std::random_shuffle(vals_.begin(), vals_.end());
111 
112  counter_ = 0;
113  }
114 
120  int next()
121  {
122  if (counter_ == size_) {
123  return -1;
124  }
125  else {
126  return vals_[counter_++];
127  }
128  }
129 };
130 
131 }
132 
133 #endif //OPENCV_FLANN_RANDOM_H
void seed_random(unsigned int seed)
Definition: random.h:47
double rand_double(double high=1.0, double low=0)
Definition: random.h:61
UniqueRandom(int n)
Definition: random.h:93
GLenum GLsizei n
Definition: random.h:81
void init(int n)
Definition: random.h:102
int next()
Definition: random.h:120
int n
Definition: legacy.hpp:3070
::max::max int
Definition: functional.hpp:324
int rand_int(int high=RAND_MAX, int low=0)
Definition: random.h:72