Logo ROOT  
Reference Guide
 
Loading...
Searching...
No Matches

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
  • relatively fast (slightly slower than TRandom2 but much faster than TRandom1)

Drawback:

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.
 
 ~TRandom3 () override
 Default destructor.
 
UInt_t GetSeed () const override
 Return one element of the generator state used to generate the random numbers.
 
virtual const UInt_tGetState () const
 
TClassIsA () const override
 
Double_t Rndm () override
 Machine independent random number generator.
 
Double_t Rndm () override
 Machine independent random number generator.
 
virtual Double_t Rndm (Int_t)
 
void RndmArray (Int_t n, Double_t *array) override
 Return an array of n random numbers uniformly distributed in ]0,1].
 
void RndmArray (Int_t n, Float_t *array) override
 Return an array of n random numbers uniformly distributed in ]0,1].
 
void SetSeed (ULong_t seed=0) override
 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.
 
void Streamer (TBuffer &) override
 Stream an object of class TRandom3.
 
void StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)
 
- Public Member Functions inherited from TRandom
 TRandom (UInt_t seed=65539)
 Default constructor. For seed see SetSeed().
 
 ~TRandom () override
 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 ULong64_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.
 
void StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)
 
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.
 
void Clear (Option_t *option="") override
 Set name and title to empty strings ("").
 
TObjectClone (const char *newname="") const override
 Make a clone of an object using the Streamer facility.
 
Int_t Compare (const TObject *obj) const override
 Compare two TNamed objects.
 
void Copy (TObject &named) const override
 Copy this to obj.
 
virtual void FillBuffer (char *&buffer)
 Encode TNamed into output buffer.
 
const char * GetName () const override
 Returns name of object.
 
const char * GetTitle () const override
 Returns title of object.
 
ULong_t Hash () const override
 Return hash value for this object.
 
Bool_t IsSortable () const override
 
void ls (Option_t *option="") const override
 List TNamed name and title.
 
TNamedoperator= (const TNamed &rhs)
 TNamed assignment operator.
 
void Print (Option_t *option="") const override
 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.
 
void StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)
 
- 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 TObjectDrawClone (Option_t *option="") const
 Draw a clone of this object in the current selected pad with: gROOT->SetSelectedPad(c1).
 
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=nullptr)
 Execute method on this object with the given parameter string, e.g.
 
virtual void Execute (TMethod *method, TObjArray *params, Int_t *error=nullptr)
 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 TObjectFindObject (const char *name) const
 Must be redefined in derived classes.
 
virtual TObjectFindObject (const TObject *obj) const
 Must be redefined in derived classes.
 
virtual Option_tGetDrawOption () 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_tGetOption () 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 (the base implementation is no-op).
 
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, void *vp)
 Only called by placement new when throwing an exception.
 
void operator delete[] (void *ptr)
 Operator delete [].
 
void operator delete[] (void *ptr, void *vp)
 Only called by placement new[] when throwing an exception.
 
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)
 
TObjectoperator= (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.
 
void StreamerNVirtual (TBuffer &ClassDef_StreamerNVirtual_b)
 
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=nullptr, Int_t option=0, Int_t bufsize=0)
 Write this object to the current directory.
 
virtual Int_t Write (const char *name=nullptr, 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 ()
 

Static Public Member Functions

static TClassClass ()
 
static const char * Class_Name ()
 
static constexpr Version_t Class_Version ()
 
static const char * DeclFileName ()
 
- Static Public Member Functions inherited from TRandom
static TClassClass ()
 
static const char * Class_Name ()
 
static constexpr Version_t Class_Version ()
 
static const char * DeclFileName ()
 
- Static Public Member Functions inherited from TNamed
static TClassClass ()
 
static const char * Class_Name ()
 
static constexpr Version_t Class_Version ()
 
static const char * DeclFileName ()
 
- Static Public Member Functions inherited from TObject
static TClassClass ()
 
static const char * Class_Name ()
 
static constexpr Version_t Class_Version ()
 
static const char * DeclFileName ()
 
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.
 

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 = (1ULL << ( 0 )) , kOverwrite = (1ULL << ( 1 )) , kWriteDelete = (1ULL << ( 2 )) }
 
enum  EDeprecatedStatusBits { kObjInCanvas = (1ULL << ( 3 )) }
 
enum  EStatusBits {
  kCanDelete = (1ULL << ( 0 )) , kMustCleanup = (1ULL << ( 3 )) , kIsReferenced = (1ULL << ( 4 )) , kHasUUID = (1ULL << ( 5 )) ,
  kCannotPick = (1ULL << ( 6 )) , kNoContextMenu = (1ULL << ( 8 )) , kInvalidObject = (1ULL << ( 13 ))
}
 
- Protected Types inherited from TObject
enum  { kOnlyPrepStep = (1ULL << ( 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 ( )
override

Default destructor.

Definition at line 90 of file TRandom3.cxx.

Member Function Documentation

◆ Class()

static TClass * TRandom3::Class ( )
static
Returns
TClass describing this class

◆ Class_Name()

static const char * TRandom3::Class_Name ( )
static
Returns
Name of this class

◆ Class_Version()

static constexpr Version_t TRandom3::Class_Version ( )
inlinestaticconstexpr
Returns
Version of this class

Definition at line 47 of file TRandom3.h.

◆ DeclFileName()

static const char * TRandom3::DeclFileName ( )
inlinestatic
Returns
Name of the file containing the class declaration

Definition at line 47 of file TRandom3.h.

◆ GetSeed()

UInt_t TRandom3::GetSeed ( ) const
inlineoverridevirtual

Return one element of the generator state used to generate the random numbers.

Note that it is not the seed of the generator that was used in the SetSeed function and the full state (624 numbers) is required to define the generator and have a reproducible output.

Reimplemented from TRandom.

Definition at line 39 of file TRandom3.h.

◆ GetState()

virtual const UInt_t * TRandom3::GetState ( ) const
inlinevirtual

Definition at line 45 of file TRandom3.h.

◆ IsA()

TClass * TRandom3::IsA ( ) const
inlineoverridevirtual
Returns
TClass describing current object

Reimplemented from TRandom.

Definition at line 47 of file TRandom3.h.

◆ Rndm() [1/3]

Double_t TRandom::Rndm ( )
overridevirtual

Machine independent random number generator.

Based on the BSD Unix (Rand) Linear congruential 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 ( )
overridevirtual

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 
)
overridevirtual

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 
)
overridevirtual

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)
overridevirtual

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.

◆ Streamer()

void TRandom3::Streamer ( TBuffer R__b)
overridevirtual

Stream an object of class TRandom3.

Reimplemented from TRandom.

Definition at line 237 of file TRandom3.cxx.

◆ StreamerNVirtual()

void TRandom3::StreamerNVirtual ( TBuffer ClassDef_StreamerNVirtual_b)
inline

Definition at line 47 of file TRandom3.h.

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:

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