Logo ROOT   6.19/01
Reference Guide
TRandom2 Class Reference


Random number generator class based on the maximally quidistributed combined Tausworthe generator by L'Ecuyer.

The period of the generator is 2**88 (about 10**26) and it uses only 3 words for the state.

For more information see: P. L'Ecuyer, Mathematics of Computation, 65, 213 (1996) P. L'Ecuyer, Mathematics of Computation, 68, 225 (1999)

The publication are available online at [http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps] [http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps]

Definition at line 27 of file TRandom2.h.

Public Member Functions

 TRandom2 (UInt_t seed=1)
 Default constructor. More...
 
virtual ~TRandom2 ()
 Default destructor. More...
 
virtual Double_t Rndm ()
 TausWorth generator from L'Ecuyer, uses as seed 3x32bits integers Use a mask of 0xffffffffUL to make in work on 64 bit machines Periodicity of about 10**26 Generate number in interval (0,1) : 0 and 1 are not included in the interval. More...
 
virtual Double_t Rndm (Int_t)
 
virtual Double_t Rndm ()
 Machine independent random number generator. More...
 
virtual void RndmArray (Int_t n, Float_t *array)
 Return an array of n random numbers uniformly distributed in ]0,1]. More...
 
virtual void RndmArray (Int_t n, Double_t *array)
 Return an array of n random numbers uniformly distributed in ]0,1]. More...
 
virtual void SetSeed (ULong_t seed=0)
 Set the generator seed. More...
 
- Public Member Functions inherited from TRandom
 TRandom (UInt_t seed=65539)
 Default constructor. For seed see SetSeed(). More...
 
virtual ~TRandom ()
 Default destructor. More...
 
virtual Int_t Binomial (Int_t ntot, Double_t prob)
 Generates a random integer N according to the binomial law. More...
 
virtual Double_t BreitWigner (Double_t mean=0, Double_t gamma=1)
 Return a number distributed following a BreitWigner function with mean and gamma. More...
 
virtual void Circle (Double_t &x, Double_t &y, Double_t r)
 Generates random vectors, uniformly distributed over a circle of given radius. More...
 
virtual Double_t Exp (Double_t tau)
 Returns an exponential deviate. More...
 
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. More...
 
virtual UInt_t GetSeed () const
 
virtual UInt_t Integer (UInt_t imax)
 Returns a random integer uniformly distributed on the interval [ 0, imax-1 ]. More...
 
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. More...
 
virtual Int_t Poisson (Double_t mean)
 Generates a random integer N according to a Poisson law. More...
 
virtual Double_t PoissonD (Double_t mean)
 Generates a random number according to a Poisson law. More...
 
virtual void Rannor (Float_t &a, Float_t &b)
 Return 2 numbers distributed following a gaussian with mean=0 and sigma=1. More...
 
virtual void Rannor (Double_t &a, Double_t &b)
 Return 2 numbers distributed following a gaussian with mean=0 and sigma=1. More...
 
virtual void ReadRandom (const char *filename)
 Reads saved random generator status from filename. More...
 
virtual Double_t Rndm (Int_t)
 
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. More...
 
virtual Double_t Uniform (Double_t x1=1)
 Returns a uniform deviate on the interval (0, x1). More...
 
virtual Double_t Uniform (Double_t x1, Double_t x2)
 Returns a uniform deviate on the interval (x1, x2). More...
 
virtual void WriteRandom (const char *filename) const
 Writes random generator status to filename. More...
 
- Public Member Functions inherited from TNamed
 TNamed ()
 
 TNamed (const char *name, const char *title)
 
 TNamed (const TString &name, const TString &title)
 
 TNamed (const TNamed &named)
 TNamed copy ctor. More...
 
virtual ~TNamed ()
 TNamed destructor. More...
 
virtual void Clear (Option_t *option="")
 Set name and title to empty strings (""). More...
 
virtual TObjectClone (const char *newname="") const
 Make a clone of an object using the Streamer facility. More...
 
virtual Int_t Compare (const TObject *obj) const
 Compare two TNamed objects. More...
 
virtual void Copy (TObject &named) const
 Copy this to obj. More...
 
virtual void FillBuffer (char *&buffer)
 Encode TNamed into output buffer. More...
 
virtual const char * GetName () const
 Returns name of object. More...
 
virtual const char * GetTitle () const
 Returns title of object. More...
 
virtual ULong_t Hash () const
 Return hash value for this object. More...
 
virtual Bool_t IsSortable () const
 
virtual void ls (Option_t *option="") const
 List TNamed name and title. More...
 
TNamedoperator= (const TNamed &rhs)
 TNamed assignment operator. More...
 
virtual void Print (Option_t *option="") const
 Print TNamed name and title. More...
 
virtual void SetName (const char *name)
 Set the name of the TNamed. More...
 
virtual void SetNameTitle (const char *name, const char *title)
 Set all the TNamed parameters (name and title). More...
 
virtual void SetTitle (const char *title="")
 Set the title of the TNamed. More...
 
virtual Int_t Sizeof () const
 Return size of the TNamed part of the TObject. More...
 
- Public Member Functions inherited from TObject
 TObject ()
 TObject constructor. More...
 
 TObject (const TObject &object)
 TObject copy ctor. More...
 
virtual ~TObject ()
 TObject destructor. More...
 
void AbstractMethod (const char *method) const
 Use this method to implement an "abstract" method that you don't want to leave purely abstract. More...
 
virtual void AppendPad (Option_t *option="")
 Append graphics object to current pad. More...
 
virtual void Browse (TBrowser *b)
 Browse object. May be overridden for another default action. More...
 
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. More...
 
virtual const char * ClassName () const
 Returns name of class to which the object belongs. More...
 
virtual void Delete (Option_t *option="")
 Delete this object. More...
 
virtual Int_t DistancetoPrimitive (Int_t px, Int_t py)
 Computes distance from point (px,py) to the object. More...
 
virtual void Draw (Option_t *option="")
 Default Draw method for all objects. More...
 
virtual void DrawClass () const
 Draw class inheritance tree of the class to which this object belongs. More...
 
virtual TObjectDrawClone (Option_t *option="") const
 Draw a clone of this object in the current selected pad for instance with: gROOT->SetSelectedPad(gPad). More...
 
virtual void Dump () const
 Dump contents of object on stdout. More...
 
virtual void Error (const char *method, const char *msgfmt,...) const
 Issue error message. More...
 
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. More...
 
virtual void Execute (TMethod *method, TObjArray *params, Int_t *error=0)
 Execute method on this object with parameters stored in the TObjArray. More...
 
virtual void ExecuteEvent (Int_t event, Int_t px, Int_t py)
 Execute action corresponding to an event at (px,py). More...
 
virtual void Fatal (const char *method, const char *msgfmt,...) const
 Issue fatal error message. More...
 
virtual TObjectFindObject (const char *name) const
 Must be redefined in derived classes. More...
 
virtual TObjectFindObject (const TObject *obj) const
 Must be redefined in derived classes. More...
 
virtual Option_tGetDrawOption () const
 Get option used by the graphics system to draw this object. More...
 
virtual const char * GetIconName () const
 Returns mime type name of object. More...
 
virtual char * GetObjectInfo (Int_t px, Int_t py) const
 Returns string containing info about the object at position (px,py). More...
 
virtual Option_tGetOption () const
 
virtual UInt_t GetUniqueID () const
 Return the unique object id. More...
 
virtual Bool_t HandleTimer (TTimer *timer)
 Execute action in response of a timer timing out. More...
 
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. More...
 
virtual void Info (const char *method, const char *msgfmt,...) const
 Issue info message. More...
 
virtual Bool_t InheritsFrom (const char *classname) const
 Returns kTRUE if object inherits from class "classname". More...
 
virtual Bool_t InheritsFrom (const TClass *cl) const
 Returns kTRUE if object inherits from TClass cl. More...
 
virtual void Inspect () const
 Dump contents of this object in a graphics canvas. More...
 
void InvertBit (UInt_t f)
 
virtual Bool_t IsEqual (const TObject *obj) const
 Default equal comparison (objects are equal if they have the same address in memory). More...
 
virtual Bool_t IsFolder () const
 Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...
 
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). More...
 
virtual Bool_t Notify ()
 This method must be overridden to handle object notification. More...
 
void Obsolete (const char *method, const char *asOfVers, const char *removedFromVers) const
 Use this method to declare a method obsolete. More...
 
void operator delete (void *ptr)
 Operator delete. More...
 
void operator delete[] (void *ptr)
 Operator delete []. More...
 
voidoperator new (size_t sz)
 
voidoperator new (size_t sz, void *vp)
 
voidoperator new[] (size_t sz)
 
voidoperator new[] (size_t sz, void *vp)
 
TObjectoperator= (const TObject &rhs)
 TObject assignment operator. More...
 
virtual void Paint (Option_t *option="")
 This method must be overridden if a class wants to paint itself. More...
 
virtual void Pop ()
 Pop on object drawn in a pad to the top of the display list. More...
 
virtual Int_t Read (const char *name)
 Read contents of object with specified name from the current directory. More...
 
virtual void RecursiveRemove (TObject *obj)
 Recursively remove this object from a list. More...
 
void ResetBit (UInt_t f)
 
virtual void SaveAs (const char *filename="", Option_t *option="") const
 Save this object in the file specified by filename. More...
 
virtual void SavePrimitive (std::ostream &out, Option_t *option="")
 Save a primitive as a C++ statement(s) on output stream "out". More...
 
void SetBit (UInt_t f, Bool_t set)
 Set or unset the user status bits as specified in f. More...
 
void SetBit (UInt_t f)
 
virtual void SetDrawOption (Option_t *option="")
 Set drawing option for object. More...
 
virtual void SetUniqueID (UInt_t uid)
 Set the unique object id. More...
 
virtual void SysError (const char *method, const char *msgfmt,...) const
 Issue system error message. More...
 
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. More...
 
virtual void Warning (const char *method, const char *msgfmt,...) const
 Issue warning message. More...
 
virtual Int_t Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
 Write this object to the current directory. More...
 
virtual Int_t Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
 Write this object to the current directory. More...
 
- Public Member Functions inherited from ROOT::Math::TRandomEngine
virtual ~TRandomEngine ()
 

Protected Attributes

UInt_t fSeed1
 
UInt_t fSeed2
 
- Protected Attributes inherited from TRandom
UInt_t fSeed
 
- Protected Attributes inherited from TNamed
TString fName
 
TString fTitle
 

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 Long_t GetDtorOnly ()
 Return destructor only flag. More...
 
static Bool_t GetObjectStat ()
 Get status of object stat flag. More...
 
static void SetDtorOnly (void *obj)
 Set destructor only flag. More...
 
static void SetObjectStat (Bool_t stat)
 Turn on/off tracking of objects in the TObjectTable. More...
 
- 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). More...
 
void MakeZombie ()
 

#include <TRandom2.h>

Inheritance diagram for TRandom2:
[legend]

Constructor & Destructor Documentation

◆ TRandom2()

TRandom2::TRandom2 ( UInt_t  seed = 1)

Default constructor.

Definition at line 36 of file TRandom2.cxx.

◆ ~TRandom2()

TRandom2::~TRandom2 ( )
virtual

Default destructor.

Definition at line 46 of file TRandom2.cxx.

Member Function Documentation

◆ Rndm() [1/3]

Double_t TRandom2::Rndm ( )
virtual

TausWorth generator from L'Ecuyer, uses as seed 3x32bits integers Use a mask of 0xffffffffUL to make in work on 64 bit machines Periodicity of about 10**26 Generate number in interval (0,1) : 0 and 1 are not included in the interval.

Reimplemented from TRandom.

Definition at line 56 of file TRandom2.cxx.

◆ Rndm() [2/3]

Double_t TRandom::Rndm

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).

Definition at line 541 of file TRandom.cxx.

◆ Rndm() [3/3]

virtual Double_t TRandom::Rndm
inline

Definition at line 51 of file TRandom.h.

◆ RndmArray() [1/2]

void TRandom2::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 75 of file TRandom2.cxx.

◆ RndmArray() [2/2]

void TRandom2::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 95 of file TRandom2.cxx.

◆ SetSeed()

void TRandom2::SetSeed ( ULong_t  seed = 0)
virtual

Set the generator seed.

If the seed given is zero, generate automatically seed values which are different every time by using TRandom3 and TUUID If a seed is given generate the other two needed for the generator state using a linear congruential generator The only condition, stated at the end of the 1999 L'Ecuyer paper is that the seeds must be greater than 1,7 and 15.

Reimplemented from TRandom.

Definition at line 120 of file TRandom2.cxx.

Member Data Documentation

◆ fSeed1

UInt_t TRandom2::fSeed1
protected

Definition at line 30 of file TRandom2.h.

◆ fSeed2

UInt_t TRandom2::fSeed2
protected

Definition at line 31 of file TRandom2.h.

Libraries for TRandom2:
[legend]

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