RNG::SWB Class Reference

A subtract with borrow random number generator by George Marsaglia (1999; internet posting). More...

#include <rng.h>

Inheritance diagram for RNG::SWB:

Collaboration diagram for RNG::SWB:

Public Member Functions
virtual std::string	to_string () const
rngint_t	value ()
	~SWB ()
void	vec_reseed (const std::vector< rngint_t > &seeds)
int	nseed ()
Public Member Functions inherited from RNG::Table256
	~Table256 ()
Public Member Functions inherited from RNG::UniformInteger
virtual	~UniformInteger ()
rngint_t	value_in_range (rngint_t range)
virtual double	realvalue (bool include_zero=true, bool include_one=true)
	Return a random value in the interval [0,1], (0,1], [0,1), or (0,1) More...
void	reseed ()
void	reseed (rngint_t)
void	reseed (rngint_t, rngint_t)
void	reseed (rngint_t, rngint_t, rngint_t)
void	reseed (rngint_t, rngint_t, rngint_t, rngint_t)

Static Public Member Functions
static SWB *	construct ()
static SWB *	construct (const std::vector< rngint_t > &)

Protected Member Functions
	SWB ()
Protected Member Functions inherited from RNG::Table256
	Table256 ()

Private Attributes
rngint_t	x
rngint_t	y

Additional Inherited Members
Protected Attributes inherited from RNG::Table256
UniformInteger *	seeder_
rngint_t	t [256]
unsigned char	c

Detailed Description

A subtract with borrow random number generator by George Marsaglia (1999; internet posting).

Here is an excerpt from the posting describing this generator: SWB is a subtract-with-borrow generator that I developed to give a simple method for producing extremely long periods: x(n)=x(n-222)-x(n-237)-borrow mod 2³². The 'borrow' is 0 unless set to 1 if computing x(n-1) caused overflow in 32-bit integer arithmetic. This generator has a very long period, 2⁷⁰⁹⁸(2⁴⁸⁰-1), about 2⁷⁵⁷⁸. It seems to pass all tests of randomness, but, suspicious of a generator so simple and fast (62 nanosecs at 300MHz), I would suggest combining SWB with KISS, MWC, SHR3, or CONG.

Definition at line 451 of file rng.h.

Constructor & Destructor Documentation

RNG::SWB::SWB ( )

protected

RNG::SWB::~SWB

(

)

Member Function Documentation

static SWB* RNG::SWB::construct ( )

static

static SWB* RNG::SWB::construct ( const std::vector< rngint_t > &  )

static

int RNG::SWB::nseed ( )

virtual

Reimplemented from RNG::Table256.

virtual std::string RNG::SWB::to_string ( ) const

inlinevirtual

Definition at line 461 of file rng.h.

References RNG::UniformInteger::nseed(), RNG::UniformInteger::value(), and RNG::UniformInteger::vec_reseed().

Here is the call graph for this function:

rngint_t RNG::SWB::value ( )

virtual

Implements RNG::UniformInteger.

void RNG::SWB::vec_reseed ( const std::vector< rngint_t > &  seeds )

virtual

Reimplemented from RNG::Table256.

Member Data Documentation

rngint_t RNG::SWB::x

private

Definition at line 454 of file rng.h.

rngint_t RNG::SWB::y

private

Definition at line 454 of file rng.h.

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

• sstmac/common/rng.h