random.h File Reference

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

#include "host.h"

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Classes
struct	_VlRand
	Random numbber generator state. More...
Typedefs
typedef struct _VlRand	VlRand
	Random numbber generator state.
Functions
VL_EXPORT void	vl_rand_permute_indexes (VlRand *self, vl_index *array, vl_size size)
	Randomly permute and array of indexes.
Setting and reading the state
VL_EXPORT void	vl_rand_init (VlRand *self)
	Initialise random number generator.
VL_EXPORT void	vl_rand_seed (VlRand *self, vl_uint32 s)
	Seed the state of the random number generator.
VL_EXPORT 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_INLINE vl_uint64	vl_rand_uint64 (VlRand *self)
	Generate a random UINT64.
VL_INLINE vl_int64	vl_rand_int63 (VlRand *self)
	Generate a random INT63.
VL_EXPORT vl_uint32	vl_rand_uint32 (VlRand *self)
	Generate a random UINT32.
VL_INLINE vl_int32	vl_rand_int31 (VlRand *self)
	Generate a random INT31.
VL_INLINE double	vl_rand_real1 (VlRand *self)
	Generate a random number in [0,1].
VL_INLINE double	vl_rand_real2 (VlRand *self)
	Generate a random number in [0,1)
VL_INLINE double	vl_rand_real3 (VlRand *self)
	Generate a random number in (0,1)
VL_INLINE double	vl_rand_res53 (VlRand *self)
	Generate a random number in [0,1) with 53-bit resolution.
VL_INLINE vl_uindex	vl_rand_uindex (VlRand *self, vl_uindex range)
	Generate a random index in a given range.

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Detailed Description

Random number generator (Random number generator)

Author:

Andrea Vedaldi

See also:

Random number generator

Definition in file random.h.

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Typedef Documentation

typedef struct _VlRand VlRand

Random numbber generator state.

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Function Documentation

VL_EXPORT void vl_rand_init

(

VlRand *

self

)

Initialise random number generator.

Parameters:

self	number generator.

Definition at line 132 of file random.c.

VL_INLINE vl_int32 vl_rand_int31

(

VlRand *

self

)

Generate a random INT31.

Parameters:

self	random number generator.

Returns:

a random number in [0, 0x7fffffff].

Definition at line 106 of file random.h.

VL_INLINE vl_int64 vl_rand_int63

(

VlRand *

self

)

Generate a random INT63.

Parameters:

self	random number generator.

Returns:

a random number in [0, 0x7fffffffffffffff].

Definition at line 95 of file random.h.

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

Randomly permute and array of indexes.

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*.

Definition at line 208 of file random.c.

VL_INLINE double vl_rand_real1

(

VlRand *

self

)

Generate a random number in [0,1].

Parameters:

self	random number generator.

Returns:

a random number.

Definition at line 117 of file random.h.

VL_INLINE double vl_rand_real2

(

VlRand *

self

)

Generate a random number in [0,1)

Parameters:

self	random number generator.

Returns:

a random number.

Definition at line 129 of file random.h.

VL_INLINE double vl_rand_real3

(

VlRand *

self

)

Generate a random number in (0,1)

Parameters:

self	random number generator.

Returns:

a random number.

Definition at line 141 of file random.h.

VL_INLINE double vl_rand_res53

(

VlRand *

self

)

Generate a random number in [0,1) with 53-bit resolution.

Parameters:

self	random number generator.

Returns:

a random number.

Definition at line 153 of file random.h.

VL_EXPORT void vl_rand_seed	(	VlRand *	self,
		vl_uint32	s
	)

Seed the state of the random number generator.

Parameters:

self	random number generator.
s	seed.

Definition at line 144 of file random.c.

VL_EXPORT 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.

Parameters:

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

Definition at line 170 of file random.c.

VL_INLINE vl_uindex vl_rand_uindex	(	VlRand *	self,
		vl_uindex	range
	)

Generate a random index in a given range.

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.

Definition at line 65 of file random.h.

VL_EXPORT vl_uint32 vl_rand_uint32

(

VlRand *

self

)

Generate a random UINT32.

Parameters:

self	random number generator.

Returns:

a random number in [0, 0xffffffff].

Definition at line 225 of file random.c.

VL_INLINE vl_uint64 vl_rand_uint64

(

VlRand *

self

)

Generate a random UINT64.

Parameters:

self	random number generator.

Returns:

a random number in [0, 0xffffffffffffffff].

Definition at line 82 of file random.h.