Documentation>C API
random.h File Reference

Random number generator (Random number generator) More...

#include "host.h"

Data Structures

struct  VlRand
 Random numbber generator state. More...
 

Functions

void vl_rand_permute_indexes (VlRand *self, vl_index *array, vl_size size)
 Randomly permute and array of indexes. More...
 
Setting and reading the state
void vl_rand_init (VlRand *self)
 Initialise random number generator. More...
 
void vl_rand_seed (VlRand *self, vl_uint32 s)
 Seed the state of the random number generator. More...
 
void vl_rand_seed_by_array (VlRand *self, vl_uint32 const key[], vl_size keySize)
 Seed the state of the random number generator by an array. More...
 
Generate random numbers
vl_uint64 vl_rand_uint64 (VlRand *self)
 Generate a random UINT64. More...
 
vl_int64 vl_rand_int63 (VlRand *self)
 Generate a random INT63. More...
 
vl_uint32 vl_rand_uint32 (VlRand *self)
 Generate a random UINT32. More...
 
vl_int32 vl_rand_int31 (VlRand *self)
 Generate a random INT31. More...
 
double vl_rand_real1 (VlRand *self)
 Generate a random number in [0,1]. More...
 
double vl_rand_real2 (VlRand *self)
 Generate a random number in [0,1) More...
 
double vl_rand_real3 (VlRand *self)
 Generate a random number in (0,1) More...
 
double vl_rand_res53 (VlRand *self)
 Generate a random number in [0,1) with 53-bit resolution. More...
 
vl_uindex vl_rand_uindex (VlRand *self, vl_uindex range)
 Generate a random index in a given range. More...
 

Detailed Description

Author
Andrea Vedaldi
See also
Random number generator

Function Documentation

void vl_rand_init ( VlRand self)
Parameters
selfnumber generator.
vl_int32 vl_rand_int31 ( VlRand self)
inline
Parameters
selfrandom number generator.
Returns
a random number in [0, 0x7fffffff].
vl_int64 vl_rand_int63 ( VlRand self)
inline
Parameters
selfrandom number generator.
Returns
a random number in [0, 0x7fffffffffffffff].
void vl_rand_permute_indexes ( VlRand self,
vl_index array,
vl_size  size 
)
Parameters
selfrandom number generator.
arrayarray of indexes.
sizenumber of element in the array.

The function uses Algorithm P, also known as Knuth shuffle.

double vl_rand_real1 ( VlRand self)
inline
Parameters
selfrandom number generator.
Returns
a random number.
double vl_rand_real2 ( VlRand self)
inline
Parameters
selfrandom number generator.
Returns
a random number.
double vl_rand_real3 ( VlRand self)
inline
Parameters
selfrandom number generator.
Returns
a random number.
double vl_rand_res53 ( VlRand self)
inline
Parameters
selfrandom number generator.
Returns
a random number.
void vl_rand_seed ( VlRand self,
vl_uint32  s 
)
Parameters
selfrandom number generator.
sseed.
void vl_rand_seed_by_array ( VlRand self,
vl_uint32 const  key[],
vl_size  keySize 
)
Parameters
selfrandom number generator.
keyarray of numbers.
keySizelength of the array.
vl_uindex vl_rand_uindex ( VlRand self,
vl_uindex  range 
)
inline
Parameters
selfrandom number generator.
rangerange.
Returns
an index sampled uniformly at random in the interval [0, range - 1]
Remarks
Currently, this function uses a simple algorithm that may yield slightly biased samples if range is not a power of two.
vl_uint32 vl_rand_uint32 ( VlRand self)
Parameters
selfrandom number generator.
Returns
a random number in [0, 0xffffffff].
vl_uint64 vl_rand_uint64 ( VlRand self)
inline
Parameters
selfrandom number generator.
Returns
a random number in [0, 0xffffffffffffffff].