StarRandom Class Reference

A class for providing random number generation. More...

#include <StarRandom.h>

Inheritance diagram for StarRandom:

Public Member Functions
Double_t	operator() () const
	Return a random number uniformly distributed between 0 and 1.
Double_t	operator() (const Double_t mn, const Double_t mx) const
	Return a random number uniformly distributed between mn and mx.
Double_t	operator() (Int_t *idummy)
Double_t	flat () const
	Return a random number uniformly distributed between 0 and 1.
Double_t	flat (const Double_t mn, const Double_t mx) const
	Return a random number uniformly distributed between mn and mx.
Double_t	expo (const Double_t mu) const
	Return a random number distribted according to exp(-mu)
Double_t	landau () const
	Return a random number distributed according to a landau.
Double_t	gauss (const Double_t sigma) const
	Return a random number distributed according to a gaussian with specified sigma.
TVector2	gauss2d (const Double_t sx, const Double_t sy, const Double_t rho) const
	Returns a pair of random numbers generated according to a 2D gaussian.
UInt_t	poisson (const Double_t mu) const

Static Public Member Functions
static StarRandom &	Instance ()
	Obtain the single instance of the random number generator.
static void	set (ROOT::Math::GSLRandomEngine *engine)
	Set the random number generator engine.
static void	capture ()
	Capture gRandom random number generator.
static void	seed (UInt_t s)
static void	seed (UShort_t seed1, UShort_t seed2)

Protected Member Functions
	ClassDef (StarRandom, 1)

Protected Attributes
UInt_t	mSeed
TArrayC	mState

Static Protected Attributes
static StarRandom *	sInstance = 0
static ROOT::Math::GSLRandomEngine *	mEngine = 0

Detailed Description

A class for providing random number generation.

StarRandom is a singleton class which allows users to implement a common random number generator interface across multiple physics event generators.

Example: Remap pythia 6's random number generator

extern "C" { Double_t pyr( Int_t *idummy ){ return StarRandom::Instance().flat(); }; };

Author

Jason C. Webb

Definition at line 30 of file StarRandom.h.

Member Function Documentation

UInt_t StarRandom::poisson

(

const Double_t

mu

)

const

Returns an integer sampled from a possion distribution with expected value mu

Definition at line 79 of file StarRandom.cxx.

void StarRandom::seed ( UInt_t  s )

static

Set the seed for this simulation. Note: Most RNG engines in GSL utilize a 32-bit seed. Those which use a smaller seed will take the provided seed modulo 32 bits. There may not be a warning issued when this occurs.

Parameters

seed	is an unsigned integer (32-bit word) providing a seed for tne RNG.

Definition at line 119 of file StarRandom.cxx.

References Instance().

Referenced by Instance(), and seed().

void StarRandom::seed ( UShort_t  seed1, UShort_t  seed2  )

static

Set a pair of seeds for this simulation. The two seeds will be combined into a single 32-bit word, and passed to the RNG engine.

Parameters

seed1	is the first RNG seed.
seed2	is the second RNG seed.

Definition at line 126 of file StarRandom.cxx.

References seed().

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

• StarGenerator/UTIL/StarRandom.h
• StarGenerator/UTIL/StarRandom.cxx