library: libCore #include "TRandom3.h"

# TRandom3

class description - source file - inheritance tree (.pdf)

## class TRandom3 : public TRandom

| Inheritance Chart:

`TObject`

<-

`TNamed`

<-

`TRandom`

<-

`TRandom3`

        public:

                           TRandom3(UInt_t seed = 65539)
                           TRandom3(const TRandom3&)
                   virtual ~TRandom3()
            static TClass* Class()
           virtual TClass* IsA() const
                 TRandom3& operator=(const TRandom3&)
          virtual Double_t Rndm(Int_t i = 0)
              virtual void RndmArray(Int_t n, Float_t* array)
              virtual void RndmArray(Int_t n, Double_t* array)
              virtual void SetSeed(UInt_t seed = 0)
              virtual void ShowMembers(TMemberInspector& insp, char* parent)
              virtual void Streamer(TBuffer& b)
                      void StreamerNVirtual(TBuffer& b)

### Data Members

        private:

          UInt_t fMt[624]
           Int_t fCount624

## Class Description

     TRandom3

     Random number generator class based on
       M. Matsumoto and T. Nishimura,
       Mersenne Twistor: 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 Twistor homepage
       http://www.math.keio.ac.jp/~matumoto/emt.html

     Advantage: large period 2**19937-1
                relativly fast
                  (only two times slower than TRandom, but
                   two times faster than TRandom2)
     Drawback:  a relative large internal state of 624 integers

     Aug.99 ROOT implementation based on CLHEP by P.Malzacher

     the original code contains the following copyright notice:

TRandom3(UInt_t seed)

    *-*-*-*-*-*-*-*-*-*-*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.

~TRandom3()

    *-*-*-*-*-*-*-*-*-*-*default destructor*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
    *-*                  ==================

Double_t Rndm(Int_t)

      Machine independent random number generator.
      Produces uniformly-distributed floating points in [0,1]
      Method: Mersenne Twistor

void RndmArray(Int_t n, Float_t *array)

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

void RndmArray(Int_t n, Double_t *array)

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

void SetSeed(UInt_t seed)

      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.

void Streamer(TBuffer &R__b)

     Stream an object of class TRandom3.

### Inline Functions

                TClass* Class()
                TClass* IsA() const
                   void ShowMembers(TMemberInspector& insp, char* parent)
                   void StreamerNVirtual(TBuffer& b)
               TRandom3 TRandom3(const TRandom3&)
              TRandom3& operator=(const TRandom3&)

Author: Peter Malzacher 31/08/99
Last update: root/base:$Name: $:$Id: TRandom3.cxx,v 1.7 2005/06/21 10:45:42 brun Exp $