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.
Setting and reading the state
void	vl_rand_init (VlRand *self)
	Initialise random number generator.
void	vl_rand_seed (VlRand *self, vl_uint32 s)
	Seed the state of the random number generator.
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.
Generate random numbers
vl_uint64	vl_rand_uint64 (VlRand *self)
	Generate a random UINT64.
vl_int64	vl_rand_int63 (VlRand *self)
	Generate a random INT63.
vl_uint32	vl_rand_uint32 (VlRand *self)
	Generate a random UINT32.
vl_int32	vl_rand_int31 (VlRand *self)
	Generate a random INT31.
double	vl_rand_real1 (VlRand *self)
	Generate a random number in [0,1].
double	vl_rand_real2 (VlRand *self)
	Generate a random number in [0,1)
double	vl_rand_real3 (VlRand *self)
	Generate a random number in (0,1)
double	vl_rand_res53 (VlRand *self)
	Generate a random number in [0,1) with 53-bit resolution.
vl_uindex	vl_rand_uindex (VlRand *self, vl_uindex range)
	Generate a random index in a given range.

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Detailed Description

Author:

Andrea Vedaldi

See also:

Random number generator

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Function Documentation

void vl_rand_init

(

VlRand *

self

)

Parameters:

self	number generator.

vl_int32 vl_rand_int31 ( VlRand *  self )

inline

Parameters:

self	random number generator.

Returns:

a random number in [0, 0x7fffffff].

vl_int64 vl_rand_int63 ( VlRand *  self )

inline

Parameters:

self	random number generator.

Returns:

a random number in [0, 0x7fffffffffffffff].

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.

double vl_rand_real1 ( VlRand *  self )

inline

Parameters:

self	random number generator.

Returns:

a random number.

double vl_rand_real2 ( VlRand *  self )

inline

Parameters:

self	random number generator.

Returns:

a random number.

double vl_rand_real3 ( VlRand *  self )

inline

Parameters:

self	random number generator.

Returns:

a random number.

double vl_rand_res53 ( VlRand *  self )

inline

Parameters:

self	random number generator.

Returns:

a random number.

void vl_rand_seed	(	VlRand *	self,
		vl_uint32	s
	)

Parameters:

self	random number generator.
s	seed.

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_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_uint32 vl_rand_uint32

(

VlRand *

self

)

Parameters:

self	random number generator.

Returns:

a random number in [0, 0xffffffff].

vl_uint64 vl_rand_uint64 ( VlRand *  self )

inline

Parameters:

self	random number generator.

Returns:

a random number in [0, 0xffffffffffffffff].