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 ()
virtual double	Rndm ()=0

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:

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