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

vl_rand_init()

void vl_rand_init

(

VlRand *

self

)

Parameters

self	number generator.

vl_rand_int31()

vl_int32 vl_rand_int31 ( VlRand *  self )

inline

Parameters

self	random number generator.

Returns

a random number in [0, 0x7fffffff].

vl_rand_int63()

vl_int64 vl_rand_int63 ( VlRand *  self )

inline

Parameters

self	random number generator.

Returns

a random number in [0, 0x7fffffffffffffff].

vl_rand_permute_indexes()

void vl_rand_permute_indexes	(	VlRand *	self,
		vl_index *	array,
		vl_size	size
	)

Parameters

self	random number generator.
array	array of indexes.
size	number of element in the array.

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

vl_rand_real1()

double vl_rand_real1 ( VlRand *  self )

inline

Parameters

self	random number generator.

Returns

a random number.

vl_rand_real2()

double vl_rand_real2 ( VlRand *  self )

inline

Parameters

self	random number generator.

Returns

a random number.

vl_rand_real3()

double vl_rand_real3 ( VlRand *  self )

inline

Parameters

self	random number generator.

Returns

a random number.

vl_rand_res53()

double vl_rand_res53 ( VlRand *  self )

inline

Parameters

self	random number generator.

Returns

a random number.

vl_rand_seed()

void vl_rand_seed	(	VlRand *	self,
		vl_uint32	s
	)

Parameters

self	random number generator.
s	seed.

vl_rand_seed_by_array()

void vl_rand_seed_by_array	(	VlRand *	self,
		vl_uint32 const	key[],
		vl_size	keySize
	)

Parameters

self	random number generator.
key	array of numbers.
keySize	length of the array.

vl_rand_uindex()

vl_uindex vl_rand_uindex ( VlRand *  self, vl_uindex  range  )

inline

Parameters

self	random number generator.
range	range.

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_rand_uint32()

vl_uint32 vl_rand_uint32

(

VlRand *

self

)

Parameters

self	random number generator.

Returns

a random number in [0, 0xffffffff].

vl_rand_uint64()

vl_uint64 vl_rand_uint64 ( VlRand *  self )

inline

Parameters

self	random number generator.

Returns

a random number in [0, 0xffffffffffffffff].