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 TRandom2 but much faster than TRandom1)

Drawback:

a relative large internal state of 624 integers
generate only 32 random bits
not passing all the random generator tests. It fails some tests in TestU01 (see [http://simul.iro.umontreal.ca/testu01/tu01.html])

An altenativly excellent generator passing all tests of TestU01, having 61 random bits and fast as Mersenne and Twister is MIXMAX (TRandomMixMax).

Definition at line 27 of file TRandom3.h.

Public Member Functions
	TRandom3 (UInt_t seed=4357)
	Default constructor If seed is 0, the seed is automatically computed via a TUUID object.

virtual	~TRandom3 ()
	Default destructor.

virtual UInt_t	GetSeed () const
	return current element of the state used for generate the random number Note that it is not the seed of the generator that was used in the SetSeed function

virtual const UInt_t *	GetState () const

virtual Double_t	Rndm ()
	Machine independent random number generator.

virtual Double_t	Rndm ()
	Machine independent random number generator.

virtual Double_t	Rndm (Int_t)

virtual void	RndmArray (Int_t n, Double_t *array)
	Return an array of n random numbers uniformly distributed in ]0,1].

virtual void	RndmArray (Int_t n, Float_t *array)
	Return an array of n random numbers uniformly distributed in ]0,1].

virtual void	SetSeed (ULong_t seed=0)
	Set the random generator sequence if seed is 0 (default value) a TUUID is generated and used to fill the first 8 integers of the seed array.

Public Member Functions inherited from TRandom
	TRandom (UInt_t seed=65539)
	Default constructor. For seed see SetSeed().

virtual	~TRandom ()
	Default destructor.

virtual Int_t	Binomial (Int_t ntot, Double_t prob)
	Generates a random integer N according to the binomial law.

virtual Double_t	BreitWigner (Double_t mean=0, Double_t gamma=1)
	Return a number distributed following a BreitWigner function with mean and gamma.

virtual void	Circle (Double_t &x, Double_t &y, Double_t r)
	Generates random vectors, uniformly distributed over a circle of given radius.

virtual Double_t	Exp (Double_t tau)
	Returns an exponential deviate.

virtual Double_t	Gaus (Double_t mean=0, Double_t sigma=1)
	Samples a random number from the standard Normal (Gaussian) Distribution with the given mean and sigma.

virtual UInt_t	Integer (UInt_t imax)
	Returns a random integer uniformly distributed on the interval [ 0, imax-1 ].

virtual Double_t	Landau (Double_t mean=0, Double_t sigma=1)
	Generate a random number following a Landau distribution with location parameter mu and scale parameter sigma: Landau( (x-mu)/sigma ) Note that mu is not the mpv(most probable value) of the Landa distribution and sigma is not the standard deviation of the distribution which is not defined.

virtual Int_t	Poisson (Double_t mean)
	Generates a random integer N according to a Poisson law.

virtual Double_t	PoissonD (Double_t mean)
	Generates a random number according to a Poisson law.

virtual void	Rannor (Double_t &a, Double_t &b)
	Return 2 numbers distributed following a gaussian with mean=0 and sigma=1.

virtual void	Rannor (Float_t &a, Float_t &b)
	Return 2 numbers distributed following a gaussian with mean=0 and sigma=1.

virtual void	ReadRandom (const char *filename)
	Reads saved random generator status from filename.

virtual void	Sphere (Double_t &x, Double_t &y, Double_t &z, Double_t r)
	Generates random vectors, uniformly distributed over the surface of a sphere of given radius.

virtual Double_t	Uniform (Double_t x1, Double_t x2)
	Returns a uniform deviate on the interval (x1, x2).

virtual Double_t	Uniform (Double_t x1=1)
	Returns a uniform deviate on the interval (0, x1).

virtual void	WriteRandom (const char *filename) const
	Writes random generator status to filename.

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TNamed &named)
	TNamed copy ctor.

	TNamed (const TString &name, const TString &title)

virtual	~TNamed ()
	TNamed destructor.

virtual void	Clear (Option_t *option="")
	Set name and title to empty strings ("").

virtual TObject *	Clone (const char *newname="") const
	Make a clone of an object using the Streamer facility.

virtual Int_t	Compare (const TObject *obj) const
	Compare two TNamed objects.

virtual void	Copy (TObject &named) const
	Copy this to obj.

virtual void	FillBuffer (char *&buffer)
	Encode TNamed into output buffer.

virtual const char *	GetName () const
	Returns name of object.

virtual const char *	GetTitle () const
	Returns title of object.

virtual ULong_t	Hash () const
	Return hash value for this object.

virtual Bool_t	IsSortable () const

virtual void	ls (Option_t *option="") const
	List TNamed name and title.

TNamed &	operator= (const TNamed &rhs)
	TNamed assignment operator.

virtual void	Print (Option_t *option="") const
	Print TNamed name and title.

virtual void	SetName (const char *name)
	Set the name of the TNamed.

virtual void	SetNameTitle (const char name, const char title)
	Set all the TNamed parameters (name and title).

virtual void	SetTitle (const char *title="")
	Set the title of the TNamed.

virtual Int_t	Sizeof () const
	Return size of the TNamed part of the TObject.

Public Member Functions inherited from TObject
	TObject ()
	TObject constructor.

	TObject (const TObject &object)
	TObject copy ctor.

virtual	~TObject ()
	TObject destructor.

void	AbstractMethod (const char *method) const
	Use this method to implement an "abstract" method that you don't want to leave purely abstract.

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad.

virtual void	Browse (TBrowser *b)
	Browse object. May be overridden for another default action.

ULong_t	CheckedHash ()
	Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object.

virtual const char *	ClassName () const
	Returns name of class to which the object belongs.

virtual void	Delete (Option_t *option="")
	Delete this object.

virtual Int_t	DistancetoPrimitive (Int_t px, Int_t py)
	Computes distance from point (px,py) to the object.

virtual void	Draw (Option_t *option="")
	Default Draw method for all objects.

virtual void	DrawClass () const
	Draw class inheritance tree of the class to which this object belongs.

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current selected pad for instance with: `gROOT->SetSelectedPad(gPad)`.

virtual void	Dump () const
	Dump contents of object on stdout.

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message.

virtual void	Execute (const char method, const char params, Int_t *error=0)
	Execute method on this object with the given parameter string, e.g.

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=0)
	Execute method on this object with parameters stored in the TObjArray.

virtual void	ExecuteEvent (Int_t event, Int_t px, Int_t py)
	Execute action corresponding to an event at (px,py).

virtual void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message.

virtual TObject *	FindObject (const char *name) const
	Must be redefined in derived classes.

virtual TObject *	FindObject (const TObject *obj) const
	Must be redefined in derived classes.

virtual Option_t *	GetDrawOption () const
	Get option used by the graphics system to draw this object.

virtual const char *	GetIconName () const
	Returns mime type name of object.

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Returns string containing info about the object at position (px,py).

virtual Option_t *	GetOption () const

virtual UInt_t	GetUniqueID () const
	Return the unique object id.

virtual Bool_t	HandleTimer (TTimer *timer)
	Execute action in response of a timer timing out.

Bool_t	HasInconsistentHash () const
	Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e.

virtual void	Info (const char method, const char msgfmt,...) const
	Issue info message.

virtual Bool_t	InheritsFrom (const char *classname) const
	Returns kTRUE if object inherits from class "classname".

virtual Bool_t	InheritsFrom (const TClass *cl) const
	Returns kTRUE if object inherits from TClass cl.

virtual void	Inspect () const
	Dump contents of this object in a graphics canvas.

void	InvertBit (UInt_t f)

Bool_t	IsDestructed () const
	IsDestructed.

virtual Bool_t	IsEqual (const TObject *obj) const
	Default equal comparison (objects are equal if they have the same address in memory).

virtual Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects).

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

R__ALWAYS_INLINE Bool_t	IsZombie () const

void	MayNotUse (const char *method) const
	Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary).

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification.

void	Obsolete (const char method, const char asOfVers, const char *removedFromVers) const
	Use this method to declare a method obsolete.

void	operator delete (void *ptr)
	Operator delete.

void	operator delete[] (void *ptr)
	Operator delete [].

void *	operator new (size_t sz)

void *	operator new (size_t sz, void *vp)

void *	operator new[] (size_t sz)

void *	operator new[] (size_t sz, void *vp)

TObject &	operator= (const TObject &rhs)
	TObject assignment operator.

virtual void	Paint (Option_t *option="")
	This method must be overridden if a class wants to paint itself.

virtual void	Pop ()
	Pop on object drawn in a pad to the top of the display list.

virtual Int_t	Read (const char *name)
	Read contents of object with specified name from the current directory.

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list.

void	ResetBit (UInt_t f)

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save this object in the file specified by filename.

virtual void	SavePrimitive (std::ostream &out, Option_t *option="")
	Save a primitive as a C++ statement(s) on output stream "out".

void	SetBit (UInt_t f)

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f.

virtual void	SetDrawOption (Option_t *option="")
	Set drawing option for object.

virtual void	SetUniqueID (UInt_t uid)
	Set the unique object id.

virtual void	SysError (const char method, const char msgfmt,...) const
	Issue system error message.

R__ALWAYS_INLINE Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

virtual void	UseCurrentStyle ()
	Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked.

virtual void	Warning (const char method, const char msgfmt,...) const
	Issue warning message.

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory.

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory.

Public Member Functions inherited from ROOT::Math::TRandomEngine
virtual	~TRandomEngine ()

Private Attributes
Int_t	fCount624

UInt_t	fMt [624]

Additional Inherited Members
Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff }

enum	{ kSingleKey = BIT(0) , kOverwrite = BIT(1) , kWriteDelete = BIT(2) }

enum	EDeprecatedStatusBits { kObjInCanvas = BIT(3) }

enum	EStatusBits { kCanDelete = BIT(0) , kMustCleanup = BIT(3) , kIsReferenced = BIT(4) , kHasUUID = BIT(5) , kCannotPick = BIT(6) , kNoContextMenu = BIT(8) , kInvalidObject = BIT(13) }

Static Public Member Functions inherited from TObject
static Longptr_t	GetDtorOnly ()
	Return destructor only flag.

static Bool_t	GetObjectStat ()
	Get status of object stat flag.

static void	SetDtorOnly (void *obj)
	Set destructor only flag.

static void	SetObjectStat (Bool_t stat)
	Turn on/off tracking of objects in the TObjectTable.

Protected Types inherited from TObject
enum	{ kOnlyPrepStep = BIT(3) }

Protected Member Functions inherited from TObject
virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected).

void	MakeZombie ()

Protected Attributes inherited from TRandom
UInt_t	fSeed

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

#include <TRandom3.h>

Inheritance diagram for TRandom3:

[legend]

Constructor & Destructor Documentation

◆ TRandom3()

TRandom3::TRandom3 ( UInt_t seed = 4357 )

Default constructor If seed is 0, the seed is automatically computed via a TUUID object.

In this case the seed is guaranteed to be unique in space and time.

Definition at line 80 of file TRandom3.cxx.

◆ ~TRandom3()

TRandom3::~TRandom3 ( )

virtual

Default destructor.

Definition at line 90 of file TRandom3.cxx.

Member Function Documentation

◆ GetSeed()

virtual UInt_t TRandom3::GetSeed ( ) const

inlinevirtual

return current element of the state used for generate the random number Note that it is not the seed of the generator that was used in the SetSeed function

Reimplemented from TRandom.

Definition at line 38 of file TRandom3.h.

◆ GetState()

virtual const UInt_t * TRandom3::GetState ( ) const

inlinevirtual

Definition at line 44 of file TRandom3.h.

◆ Rndm() [1/3]

Double_t TRandom::Rndm ( )

virtual

Machine independent random number generator.

Based on the BSD Unix (Rand) Linear congrential generator. Produces uniformly-distributed floating points between 0 and 1. Identical sequence on all machines of >= 32 bits. Periodicity = 2**31, generates a number in (0,1). Note that this is a generator which is known to have defects (the lower random bits are correlated) and therefore should NOT be used in any statistical study).

Reimplemented from TRandom.

Definition at line 49 of file TRandom.cxx.

◆ Rndm() [2/3]

Double_t TRandom3::Rndm ( )

virtual

Machine independent random number generator.

Produces uniformly-distributed floating points in (0,1) Method: Mersenne Twister

Reimplemented from TRandom.

Definition at line 99 of file TRandom3.cxx.

◆ Rndm() [3/3]

virtual Double_t TRandom::Rndm ( Int_t )

inlinevirtual

Reimplemented from TRandom.

Definition at line 51 of file TRandom.h.

◆ RndmArray() [1/2]

void TRandom3::RndmArray	(	Int_t	n,
		Double_t *	array
	)

virtual

Return an array of n random numbers uniformly distributed in ]0,1].

Reimplemented from TRandom.

Definition at line 151 of file TRandom3.cxx.

◆ RndmArray() [2/2]

void TRandom3::RndmArray	(	Int_t	n,
		Float_t *	array
	)

virtual

Return an array of n random numbers uniformly distributed in ]0,1].

Reimplemented from TRandom.

Definition at line 143 of file TRandom3.cxx.

◆ SetSeed()

void TRandom3::SetSeed ( ULong_t seed = 0 )

virtual

Set the random generator sequence if seed is 0 (default value) a TUUID is generated and used to fill the first 8 integers of the seed array.

In this case the seed is guaranteed to be unique in space and time. Use upgraded seeding procedure to fix a known problem when seeding with values with many zero in the bit pattern (like 2**28). see http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/emt19937ar.html

Reimplemented from TRandom.

Definition at line 206 of file TRandom3.cxx.

Member Data Documentation

◆ fCount624

Int_t TRandom3::fCount624

private

Definition at line 31 of file TRandom3.h.

◆ fMt

UInt_t TRandom3::fMt[624]

private

Definition at line 30 of file TRandom3.h.

Libraries for TRandom3:

[legend]

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

math/mathcore/inc/TRandom3.h
math/mathcore/src/TRandom3.cxx

Public Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ TRandom3()

◆ ~TRandom3()

Member Function Documentation

◆ GetSeed()

◆ GetState()

◆ Rndm() [1/3]

◆ Rndm() [2/3]

◆ Rndm() [3/3]

◆ RndmArray() [1/2]

◆ RndmArray() [2/2]

◆ SetSeed()

Member Data Documentation

◆ fCount624

◆ fMt