#include <CURandom.h>

Public Member Functions
	Random ()

	~Random ()

void	dispose ()

bool	init ()

bool	initWithSeed (Uint64 seed)

bool	initWithArray (Uint64 *key, size_t len)

void	reset ()

void	reset (Uint64 seed)

void	reset (Uint64 *key, size_t len)

Uint64	getSeed () const

const std::vector< Uint64 > &	getKeys () const

Uint64	getUint64 ()

Sint64	getSint64 ()

Uint64	getOpenUint64 (Uint64 min, Uint64 max)

Uint64	getClosedUint64 (Uint64 min, Uint64 max)

Sint64	getOpenSint64 (Sint64 min, Sint64 max)

Sint64	getClosedSint64 (Sint64 min, Sint64 max)

Uint32	getUint32 ()

Sint32	getSint32 ()

Uint16	getUint16 ()

Sint16	getSint16 ()

Uint8	getUint8 ()

Sint8	getSint8 ()

bool	getBool ()

double	getDouble ()

double	getClosedDouble ()

double	getHalfOpenDouble ()

double	getOpenDouble ()

double	getClosedDouble (double min, double max)

double	getOpenDouble (double min, double max)

double	getRightOpenDouble (double min, double max)

double	getLeftOpenDouble (double min, double max)

double	getFloat ()

float	getClosedFloat (float min, float max)

float	getOpenFloat (float min, float max)

float	getRightOpenFloat (float min, float max)

float	getLeftOpenFloat (float min, float max)

template<typename T >
T *	getChoice (T *data, size_t len)

template<typename T >
T *	getChoice (const std::vector< T > &data)

template<typename T >
void	shuffle (T *data, size_t len)

template<typename T >
void	shuffle (std::vector< T > &data)

double	getNormal (double mu, double sigma)

double	getLogNorm (double mu, double sigma)

double	getExp (double mu)

double	getGamma (double alpha, double beta)

double	getBeta (double alpha, double beta)

double	getPareto (double xm, double alpha)

double	getWeibull (double k, double lambda)

Static Public Member Functions
static std::shared_ptr< Random >	alloc ()

static std::shared_ptr< Random >	allocWithSeed (Uint64 seed)

static std::shared_ptr< Random >	allocWithArray (Uint64 *key, size_t len)

Detailed Description

This class is a 64 bit Marseene Twister psuedo-random generator.

This generator is guaranteed to be cross-platform with respect to random integers. So, given the same seed, any two different platforms will generate the same sequence of random integers.

For the case of reals (e.g. doubles), cross-platform support depends on IEEE 754, which is supported by all modern hardware. Any two platforms that support IEEE 754 should generate the same numbers for the same hardware.

However, there are no cross-platform guarantees for any of the distribution functions like getNormal or getGamma. This distributions use complex mathematical functions that may be implemented differently on different platforms.

Constructor & Destructor Documentation

◆ Random()

cugl::Random::Random ( )

inline

Creates an uninitialized generator with no sequence.

You must initialize the generator to create a pseudo-random sequence.

◆ ~Random()

cugl::Random::~Random ( )

inline

Deletes this generator, disposing all resources.

Member Function Documentation

◆ alloc()

static std::shared_ptr< Random > cugl::Random::alloc ( )

inlinestatic

Returns a newly allocated psuedorandom number generator with the given time

The random number generator is the classic 64 bit version implement here

http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/VERSIONS/C-LANG/mt19937-64.c

Returns: a newly allocated psuedorandom number generator with the given time

◆ allocWithArray()

static std::shared_ptr< Random > cugl::Random::allocWithArray	(	Uint64 *	key,
		size_t	len
	)

inlinestatic

Returns a newly allocated psuedorandom number generator with the given keys

The random number generator is the classic 64 bit version implement here

http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/VERSIONS/C-LANG/mt19937-64.c

Generators with the same key sequence will generate the same numbers.

Parameters

key	The array of generator keys
len	The key length

Returns: a newly allocated psuedorandom number generator with the given keys

◆ allocWithSeed()

static std::shared_ptr< Random > cugl::Random::allocWithSeed ( Uint64 seed )

inlinestatic

Returns a newly allocated psuedorandom number generator with the given seed

The random number generator is the classic 64 bit version implement here

http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/VERSIONS/C-LANG/mt19937-64.c

Generators with the same seed will generate the same numbers.

Parameters

seed	The generator seed

Returns: a newly allocated psuedorandom number generator with the given seed

◆ dispose()

void cugl::Random::dispose ( )

Disposes the psuedo-random sequence for this generator

You must reinitialize the generator to use it.

◆ getBeta()

double cugl::Random::getBeta	(	double	alpha,
		double	beta
	)

inline

Returns the next element in the beta distribution.

The parameters alpha and beta should be positive. The values returned are between 0 and 1.

The mean is alpha/(alpha+beta) and the variance is (alpha*beta)/((alpha+beta+1)*(alpha+beta)^2)

Parameters

alpha	The first shape parameter (should be > 0)
beta	The second shape parameter (should be > 0)

Returns: the next element in the beta distribution.

◆ getBool()

bool cugl::Random::getBool ( )

inline

Returns the next pseudorandom value true or false.

Returns: the next pseudorandom value true or false.

◆ getChoice() [1/2]

template<typename T >

T * cugl::Random::getChoice ( const std::vector< T > & data )

inline

Returns a pointer to a randomly selected item in data

The function works on a vector. If the vector is empty, this function returns nullptr.

Parameters

data	The vector to select from

Returns: a pointer to a randomly selected item in data

◆ getChoice() [2/2]

template<typename T >

T * cugl::Random::getChoice	(	T *	data,
		size_t	len
	)

inline

Returns a pointer to a randomly selected item in data

The function works on an array of data. The length must be specified. If len == 0, this function returns nullptr.

Parameters

data	The array to select from
len	The number of elements in the array

Returns: a pointer to a randomly selected item in data

◆ getClosedDouble() [1/2]

double cugl::Random::getClosedDouble ( )

inline

Returns the next pseudorandom double in [0,1]

Both endpoints of the interval are included.

Returns: the next pseudorandom double in [0,1]

◆ getClosedDouble() [2/2]

double cugl::Random::getClosedDouble	(	double	min,
		double	max
	)

inline

Returns the next pseudorandom double in [min,max]

Both endpoints of the interval are included. If min > max, the result is undefined.

Returns: the next pseudorandom double in [min,max]

◆ getClosedFloat()

float cugl::Random::getClosedFloat	(	float	min,
		float	max
	)

inline

Returns the next pseudorandom float in [min,max]

Both endpoints of the interval are included. If min > max, the result is undefined.

Returns: the next pseudorandom float in [min,max]

◆ getClosedSint64()

Sint64 cugl::Random::getClosedSint64	(	Sint64	min,
		Sint64	max
	)

inline

Returns the next pseudorandom signed integer in [min, max]

If min >= max, the result is undefined.

Returns: the next pseudorandom signed integer in [min, max]

◆ getClosedUint64()

Uint64 cugl::Random::getClosedUint64	(	Uint64	min,
		Uint64	max
	)

inline

Returns the next pseudorandom integer in [min, max]

If min >= max, the result is undefined.

Returns: the next pseudorandom integer in [min, max]

◆ getDouble()

double cugl::Random::getDouble ( )

inline

Returns the next pseudorandom double in [0,1)

Only the endpoint 0 is included. To get a random double in the interval (0,1], simply subtract this number from 1.

This function is equivalent to getHalfOpenDouble, as that is often the desired behavior of random generators.

Returns: the next pseudorandom double in [0,1)

◆ getExp()

double cugl::Random::getExp ( double mu )

inline

Returns the next element in the exponential distribution.

The value mu is the desired mean. It should be nonzero. Returned values range from 0 to positive infinity if mu is positive, and from negative infinity to 0 if mu is negative.

Parameters

mu	The standard deviation

Returns: the next element in the exponential distribution.

◆ getFloat()

double cugl::Random::getFloat ( )

inline

Returns the next pseudorandom float in [0,1)

Only the endpoint 0 is included. To get a random double in the interval (0,1], simply subtract this number from 1.

Returns: the next pseudorandom float in [0,1)

◆ getGamma()

double cugl::Random::getGamma	(	double	alpha,
		double	beta
	)

inline

Returns the next element in the gamma distribution.

The parameters alpha and beta should be positive. The probability distribution function is

             x^(alpha - 1) * exp(-x * beta) * beta^alpha
 pdf(x) =  -----------------------------------------------
                              gamma(alpha)

where gamma() is the gamma function. See

https://en.wikipedia.org/wiki/Gamma_distribution

The mean is is alpha/beta, and the variance is alpha/(beta^2).

Parameters

alpha	The shape parameter (should be > 0)
beta	The rate parameter (should be > 0)

Returns: the next element in the gamma distribution.

◆ getHalfOpenDouble()

double cugl::Random::getHalfOpenDouble ( )

inline

Returns the next pseudorandom double in [0,1)

Only the endpoint 0 is included. To get a random double in the interval (0,1], simply subtract this number from 1.

Returns: the next pseudorandom double in [0,1)

◆ getKeys()

const std::vector< Uint64 > & cugl::Random::getKeys ( ) const

inline

Returns the key sequence for the given generator.

If a seed was used in place of a key sequence, this method will return an empty vector.

Returns: the seed for the given generator.

◆ getLeftOpenDouble()

double cugl::Random::getLeftOpenDouble	(	double	min,
		double	max
	)

inline

Returns the next pseudorandom double in (min,max]

Only the second endpoint of the interval is included. If min >= max, the result is undefined.

Returns: the next pseudorandom double in (min,max]

◆ getLeftOpenFloat()

float cugl::Random::getLeftOpenFloat	(	float	min,
		float	max
	)

inline

Returns the next pseudorandom float in (min,max]

Only the second endpoint of the interval is included. If min >= max, the result is undefined.

Returns: the next pseudorandom float in (min,max]

◆ getLogNorm()

double cugl::Random::getLogNorm	(	double	mu,
		double	sigma
	)

inline

Returns the next element in the log normal distribution.

If you take the natural logarithm of this distribution, you will get a normal distribution with mean mu and standard deviation sigma. Parameter mu can have any value, and sigma must be greater than zero.

Parameters

mu	The mean
sigma	The standard deviation

Returns: the next element in the log normal distribution.

◆ getNormal()

double cugl::Random::getNormal	(	double	mu,
		double	sigma
	)

inline

Returns the next element in the normal distribution.

The value mu is the mean, and sigma is the standard deviation. Parameter mu can have any value, and sigma must be greater than zero.

Parameters

mu	The mean
sigma	The standard deviation

Returns: the next element in the normal distribution.

◆ getOpenDouble() [1/2]

double cugl::Random::getOpenDouble ( )

inline

Returns the next pseudorandom double in (0,1)

Neither endpoint in the interval is included.

Returns: the next pseudorandom double in (0,1)

◆ getOpenDouble() [2/2]

double cugl::Random::getOpenDouble	(	double	min,
		double	max
	)

inline

Returns the next pseudorandom double in (min,max)

Neither of the endpoints of the interval are included. If min >= max, the result is undefined.

Returns: the next pseudorandom double in (min,max)

◆ getOpenFloat()

float cugl::Random::getOpenFloat	(	float	min,
		float	max
	)

inline

Returns the next pseudorandom float in (min,max)

Neither of the endpoints of the interval are included. If min >= max, the result is undefined.

Returns: the next pseudorandom float in (min,max)

◆ getOpenSint64()

Sint64 cugl::Random::getOpenSint64	(	Sint64	min,
		Sint64	max
	)

inline

Returns the next pseudorandom signed integer in [min, max)

If min >= max, the result is undefined.

Returns: the next pseudorandom signed integer in [min, max)

◆ getOpenUint64()

Uint64 cugl::Random::getOpenUint64	(	Uint64	min,
		Uint64	max
	)

inline

Returns the next pseudorandom integer in [min, max)

If min >= max, the result is undefined.

Returns: the next pseudorandom integer in [min, max)

◆ getPareto()

double cugl::Random::getPareto	(	double	xm,
		double	alpha
	)

inline

Returns the next element in the Pareto distribution.

The mean is infty for alpha <= 1 and (alpha*xm)/(alpha-1) for alpha > 1. The variance is infty for alpha <= 2 and (alpha*xm^2)/((alpha-2)*(alpha-1)^2) for alpha > 2.

Parameters

xm	The scale parameter
alpha	The shape parameter

Returns: the next element in the Pareto distribution.

◆ getRightOpenDouble()

double cugl::Random::getRightOpenDouble	(	double	min,
		double	max
	)

inline

Returns the next pseudorandom double in [min,max)

Only the first endpoint of the interval is included. If min >= max, the result is undefined.

Returns: the next pseudorandom double in [min,max)

◆ getRightOpenFloat()

float cugl::Random::getRightOpenFloat	(	float	min,
		float	max
	)

inline

Returns the next pseudorandom float in [min,max)

Only the first endpoint of the interval is included. If min >= max, the result is undefined.

Returns: the next pseudorandom float in [min,max)

◆ getSeed()

Uint64 cugl::Random::getSeed ( ) const

inline

Returns the seed for the given generator.

If a key sequence was used in place of a seed, this method will return 0.

Returns: the seed for the given generator.

◆ getSint16()

Sint16 cugl::Random::getSint16 ( )

inline

Returns the next pseudorandom integer in [-2^15, 2^15-1]

Returns: the next pseudorandom integer in [-2^15, 2^15-1]

◆ getSint32()

Sint32 cugl::Random::getSint32 ( )

inline

Returns the next pseudorandom integer in [-2^31, 2^31-1]

Returns: the next pseudorandom integer in [-2^31, 2^31-1]

◆ getSint64()

Sint64 cugl::Random::getSint64 ( )

inline

Returns the next pseudorandom integer in [-2^63, 2^63-1]

Returns: the next pseudorandom integer in [-2^63, 2^63-1]

◆ getSint8()

Sint8 cugl::Random::getSint8 ( )

inline

Returns the next pseudorandom integer in [-128,127]

Returns: the next pseudorandom integer in [-128,127]

◆ getUint16()

Uint16 cugl::Random::getUint16 ( )

inline

Returns the next pseudorandom integer in [0, 2^16-1]

Returns: the next pseudorandom integer in [0, 2^16-1]

◆ getUint32()

Uint32 cugl::Random::getUint32 ( )

inline

Returns the next pseudorandom integer in [0, 2^32-1]

Returns: the next pseudorandom integer in [0, 2^32-1]

◆ getUint64()

Uint64 cugl::Random::getUint64 ( )

inline

Returns the next pseudorandom integer in [0, 2^64-1]

Returns: the next pseudorandom integer in [0, 2^64-1]

◆ getUint8()

Uint8 cugl::Random::getUint8 ( )

inline

Returns the next pseudorandom integer in [0, 255]

Returns: the next pseudorandom integer in [0, 255]

◆ getWeibull()

double cugl::Random::getWeibull	(	double	k,
		double	lambda
	)

inline

Returns the next element in the Weibull distribution.

The mean is lambda * gamma(1+1/k) and the variance is

lambda^2 * (gamma(1+2/k)-gamma(1+1/k)^2)

where gamma() is the gamma function.

Parameters

k	The shape parameter
lambda	The scale parameter

Returns: the next element in the Weibull distribution.

◆ init()

bool cugl::Random::init ( )

Initializes a psuedorandom number generator with the current time.

The random number generator is the classic 64 bit version implement here

http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/VERSIONS/C-LANG/mt19937-64.c

Returns: true if initialization was successful

◆ initWithArray()

bool cugl::Random::initWithArray	(	Uint64 *	key,
		size_t	len
	)

Initializes a psuedorandom number generator with the given keys

The random number generator is the classic 64 bit version implement here

http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/VERSIONS/C-LANG/mt19937-64.c

Generators with the same key sequence will generate the same numbers.

Parameters

key	The array of generator keys
len	The key length

Returns: true if initialization was successful

◆ initWithSeed()

bool cugl::Random::initWithSeed ( Uint64 seed )

Initializes a psuedorandom number generator with the given seed

The random number generator is the classic 64 bit version implement here

http://www.math.sci.hiroshima-u.ac.jp/m-mat/MT/VERSIONS/C-LANG/mt19937-64.c

Generators with the same seed will generate the same numbers.

Parameters

seed	The generator seed

Returns: true if initialization was successful

◆ reset() [1/3]

void cugl::Random::reset ( )

Resets the random generator to use the current time as the seed.

The previous pseudo-random sequence will be discarded and replaced with the new one. Generation will start at the beginning of the new sequence.

◆ reset() [2/3]

void cugl::Random::reset	(	Uint64 *	key,
		size_t	len
	)

Resets the random generator to use the given keys.

The previous pseudo-random sequence will be discarded and replaced with the new one. Generation will start at the beginning of the new sequence.

Parameters

key	The array of generator keys
len	The key length

◆ reset() [3/3]

void cugl::Random::reset ( Uint64 seed )

Resets the random generator to use the given seed.

The previous pseudo-random sequence will be discarded and replaced with the new one. Generation will start at the beginning of the new sequence.

Parameters

seed	The new generator seed

◆ shuffle() [1/2]

template<typename T >

void cugl::Random::shuffle ( std::vector< T > & data )

inline

Randomly shuffles the data in place

The function works on a vector.

Parameters

data	The vector to shuffle

◆ shuffle() [2/2]

template<typename T >

void cugl::Random::shuffle	(	T *	data,
		size_t	len
	)

inline

Randomly shuffles the data in place

The function works on an array of data. The length must be specified.

Parameters

data	The array to shuffle
len	The number of elements in the array

The documentation for this class was generated from the following file:

/Users/wmwhite/Developer/CUGL/include/cugl/core/util/CURandom.h

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Random()

◆ ~Random()

Member Function Documentation

◆ alloc()

◆ allocWithArray()

◆ allocWithSeed()

◆ dispose()

◆ getBeta()

◆ getBool()

◆ getChoice() [1/2]

◆ getChoice() [2/2]

◆ getClosedDouble() [1/2]

◆ getClosedDouble() [2/2]

◆ getClosedFloat()

◆ getClosedSint64()

◆ getClosedUint64()

◆ getDouble()

◆ getExp()

◆ getFloat()

◆ getGamma()

◆ getHalfOpenDouble()

◆ getKeys()

◆ getLeftOpenDouble()

◆ getLeftOpenFloat()

◆ getLogNorm()

◆ getNormal()

◆ getOpenDouble() [1/2]

◆ getOpenDouble() [2/2]

◆ getOpenFloat()

◆ getOpenSint64()

◆ getOpenUint64()

◆ getPareto()

◆ getRightOpenDouble()

◆ getRightOpenFloat()

◆ getSeed()

◆ getSint16()

◆ getSint32()

◆ getSint64()

◆ getSint8()

◆ getUint16()

◆ getUint32()

◆ getUint64()

◆ getUint8()

◆ getWeibull()

◆ init()

◆ initWithArray()

◆ initWithSeed()

◆ reset() [1/3]

◆ reset() [2/3]

◆ reset() [3/3]

◆ shuffle() [1/2]

◆ shuffle() [2/2]