ROOT::Math::MersenneTwisterEngine Class Reference

Random number generator class based on M.

Matsumoto and T. Nishimura, Mersenne Twister: A 623-diminsionally equidistributed uniform pseudorandom number generator ACM Transactions on Modeling and Computer Simulation, Vol. 8, No. 1, January 1998, pp 3–30.

For more information see the Mersenne Twister homepage [http://www.math.keio.ac.jp/~matumoto/emt.html]

Advantage:

• large period 2**19937 -1
• relativly fast (slightly slower than TRandom1 and TRandom2 but much faster than TRandom1)

Note that this is a 32 bit implementation. Only 32 bits of the returned double numbers are random. in case more precision is needed, one should use an engine providing at least 48 random bits.

Drawback: a relative large internal state of 624 integers

Definition at line 50 of file MersenneTwisterEngine.h.

Public Types
typedef TRandomEngine	BaseType
typedef uint32_t	Result_t
typedef uint32_t	StateInt_t

Public Member Functions
	MersenneTwisterEngine (uint32_t seed=4357)
virtual	~MersenneTwisterEngine ()
uint32_t	IntRndm ()
double	operator() ()
virtual double	Rndm ()
void	SetSeed (Result_t seed)
	set the seed x More...
Public Member Functions inherited from ROOT::Math::TRandomEngine
virtual	~TRandomEngine ()

Static Public Member Functions
static unsigned int	MaxInt ()
	maximum integer taht can be generated More...
static unsigned int	MinInt ()
	minimum integer taht can be generated More...
static std::string	Name ()
static int	Size ()

Protected Member Functions
int	Counter () const
void	GetState (std::vector< uint32_t > &state)
void	SetState (const std::vector< uint32_t > &state)

Private Types
enum	{ kSize =624 }

Private Member Functions
uint32_t	IntRndm_impl ()
double	Rndm_impl ()
	generate a random double number More...

Private Attributes
int	fCount624
uint32_t	fMt [kSize]

#include <Math/MersenneTwisterEngine.h>

Inheritance diagram for ROOT::Math::MersenneTwisterEngine:

Member Typedef Documentation

BaseType

typedef TRandomEngine ROOT::Math::MersenneTwisterEngine::BaseType

Definition at line 55 of file MersenneTwisterEngine.h.

Result_t

typedef uint32_t ROOT::Math::MersenneTwisterEngine::Result_t

Definition at line 56 of file MersenneTwisterEngine.h.

StateInt_t

typedef uint32_t ROOT::Math::MersenneTwisterEngine::StateInt_t

Definition at line 57 of file MersenneTwisterEngine.h.

Member Enumeration Documentation

anonymous enum

anonymous enum

private

Enumerator
kSize

Definition at line 111 of file MersenneTwisterEngine.h.

Constructor & Destructor Documentation

MersenneTwisterEngine()

ROOT::Math::MersenneTwisterEngine::MersenneTwisterEngine ( uint32_t  seed = 4357 )

inline

Definition at line 60 of file MersenneTwisterEngine.h.

~MersenneTwisterEngine()

virtual ROOT::Math::MersenneTwisterEngine::~MersenneTwisterEngine ( )

inlinevirtual

Definition at line 64 of file MersenneTwisterEngine.h.

Member Function Documentation

Counter()

int ROOT::Math::MersenneTwisterEngine::Counter ( ) const

inlineprotected

Definition at line 103 of file MersenneTwisterEngine.h.

GetState()

void ROOT::Math::MersenneTwisterEngine::GetState ( std::vector< uint32_t > &  state )

inlineprotected

Definition at line 97 of file MersenneTwisterEngine.h.

IntRndm()

uint32_t ROOT::Math::MersenneTwisterEngine::IntRndm ( )

inline

Definition at line 73 of file MersenneTwisterEngine.h.

IntRndm_impl()

uint32_t ROOT::Math::MersenneTwisterEngine::IntRndm_impl ( )

private

MaxInt()

static unsigned int ROOT::Math::MersenneTwisterEngine::MaxInt ( )

inlinestatic

maximum integer taht can be generated

Definition at line 80 of file MersenneTwisterEngine.h.

MinInt()

static unsigned int ROOT::Math::MersenneTwisterEngine::MinInt ( )

inlinestatic

minimum integer taht can be generated

Definition at line 78 of file MersenneTwisterEngine.h.

Name()

static std::string ROOT::Math::MersenneTwisterEngine::Name ( )

inlinestatic

Definition at line 84 of file MersenneTwisterEngine.h.

operator()()

double ROOT::Math::MersenneTwisterEngine::operator() ( )

inline

Definition at line 71 of file MersenneTwisterEngine.h.

Rndm()

virtual double ROOT::Math::MersenneTwisterEngine::Rndm ( )

inlinevirtual

Implements ROOT::Math::TRandomEngine.

Definition at line 68 of file MersenneTwisterEngine.h.

Rndm_impl()

double ROOT::Math::MersenneTwisterEngine::Rndm_impl ( )

private

generate a random double number

Definition at line 37 of file MersenneTwisterEngine.cxx.

SetSeed()

void ROOT::Math::MersenneTwisterEngine::SetSeed

(

Result_t

seed

)

set the seed x

Definition at line 24 of file MersenneTwisterEngine.cxx.

SetState()

void ROOT::Math::MersenneTwisterEngine::SetState ( const std::vector< uint32_t > &  state )

inlineprotected

Definition at line 91 of file MersenneTwisterEngine.h.

Size()

static int ROOT::Math::MersenneTwisterEngine::Size ( )

inlinestatic

Definition at line 82 of file MersenneTwisterEngine.h.

Member Data Documentation

fCount624

int ROOT::Math::MersenneTwisterEngine::fCount624

private

Definition at line 115 of file MersenneTwisterEngine.h.

fMt

uint32_t ROOT::Math::MersenneTwisterEngine::fMt[kSize]

private

Definition at line 114 of file MersenneTwisterEngine.h.

Libraries for ROOT::Math::MersenneTwisterEngine:

[legend]