CLHEP::RandPoisson Class Reference

#include <RandPoisson.h>

Inheritance diagram for CLHEP::RandPoisson:

Public Member Functions
	RandPoisson (HepRandomEngine &anEngine, double a1=1.0)
	RandPoisson (HepRandomEngine *anEngine, double a1=1.0)
virtual	~RandPoisson ()
std::ostream &	put (std::ostream &os) const
std::istream &	get (std::istream &is)
long	fire ()
long	fire (double mean)
void	fireArray (const int size, long *vect)
void	fireArray (const int size, long *vect, double mean)
double	operator() ()
double	operator() (double mean)
std::string	name () const
HepRandomEngine &	engine ()
Public Member Functions inherited from CLHEP::HepRandom
	HepRandom ()
	HepRandom (long seed)
	HepRandom (HepRandomEngine &algorithm)
	HepRandom (HepRandomEngine *algorithm)
virtual	~HepRandom ()
double	flat ()
void	flatArray (const int size, double *vect)
double	flat (HepRandomEngine *theNewEngine)
void	flatArray (HepRandomEngine *theNewEngine, const int size, double *vect)
virtual double	operator() ()
virtual std::string	name () const
virtual HepRandomEngine &	engine ()
virtual std::ostream &	put (std::ostream &os) const
virtual std::istream &	get (std::istream &is)

Static Public Member Functions
static long	shoot (double mean=1.0)
static void	shootArray (const int size, long *vect, double mean=1.0)
static long	shoot (HepRandomEngine *anEngine, double mean=1.0)
static void	shootArray (HepRandomEngine *anEngine, const int size, long *vect, double mean=1.0)
static std::string	distributionName ()
Static Public Member Functions inherited from CLHEP::HepRandom
static void	setTheSeed (long seed, int lxr=3)
static long	getTheSeed ()
static void	setTheSeeds (const long *seeds, int aux=-1)
static const long *	getTheSeeds ()
static void	getTheTableSeeds (long *seeds, int index)
static HepRandom *	getTheGenerator ()
static void	setTheEngine (HepRandomEngine *theNewEngine)
static HepRandomEngine *	getTheEngine ()
static void	saveEngineStatus (const char filename[]="Config.conf")
static void	restoreEngineStatus (const char filename[]="Config.conf")
static std::ostream &	saveFullState (std::ostream &os)
static std::istream &	restoreFullState (std::istream &is)
static std::ostream &	saveDistState (std::ostream &os)
static std::istream &	restoreDistState (std::istream &is)
static std::ostream &	saveStaticRandomStates (std::ostream &os)
static std::istream &	restoreStaticRandomStates (std::istream &is)
static void	showEngineStatus ()
static int	createInstance ()
static std::string	distributionName ()

Protected Member Functions
HepRandomEngine *	getLocalEngine ()

Static Protected Member Functions
static double	getOldMean ()
static double	getMaxMean ()
static void	setOldMean (double val)
static double *	getPStatus ()
static void	setPStatus (double sq, double alxm, double g1)

Protected Attributes
double	meanMax
double	defaultMean

Additional Inherited Members
Static Protected Attributes inherited from CLHEP::HepRandom
static const long	seedTable [215][2]

Detailed Description

Author

Definition at line 41 of file RandPoisson.h.

Constructor & Destructor Documentation

RandPoisson() [1/2]

CLHEP::RandPoisson::RandPoisson ( HepRandomEngine &  anEngine, double  a1 = 1.0  )

inline

RandPoisson() [2/2]

CLHEP::RandPoisson::RandPoisson ( HepRandomEngine *  anEngine, double  a1 = 1.0  )

inline

~RandPoisson()

CLHEP::RandPoisson::~RandPoisson ( )

virtual

Definition at line 45 of file RandPoisson.cc.

                          {
}

Member Function Documentation

distributionName()

static std::string CLHEP::RandPoisson::distributionName ( )

inlinestatic

Definition at line 93 of file RandPoisson.h.

{return "RandPoisson";}  

engine()

HepRandomEngine & CLHEP::RandPoisson::engine ( )

virtual

Reimplemented from CLHEP::HepRandom.

Reimplemented in CLHEP::RandPoissonQ.

Definition at line 38 of file RandPoisson.cc.

{return *localEngine;}

Referenced by CLHEP::RandPoissonQ::engine().

fire() [1/2]

long CLHEP::RandPoisson::fire

(

)

Definition at line 215 of file RandPoisson.cc.

                       {
  return long(fire( defaultMean ));
}

Referenced by fire(), fireArray(), and operator()().

fire() [2/2]

long CLHEP::RandPoisson::fire

(

double

mean

)

Definition at line 219 of file RandPoisson.cc.

                                {
 
// Returns as a floating-point number an integer value that is a random
// deviation drawn from a Poisson distribution of mean xm, using flat()
// as a source of uniform random numbers.
// (Adapted from Numerical Recipes in C)
 
  double em, t, y;
  double sq, alxm, g1;
 
  sq = status[0];
  alxm = status[1];
  g1 = status[2];
 
  if( xm == -1 ) return 0;
  if( xm < 12.0 ) {
    if( xm != oldm ) {
      oldm = xm;
      g1 = std::exp(-xm);
    }
    em = -1;
    t = 1.0;
    do {
      em += 1.0;
      t *= localEngine->flat();
    } while( t > g1 );
  }
  else if ( xm < meanMax ) {
    if ( xm != oldm ) {
      oldm = xm;
      sq = std::sqrt(2.0*xm);
      alxm = std::log(xm);
      g1 = xm*alxm - gammln(xm + 1.0);
    }
    do {
      do {
    y = std::tan(CLHEP::pi*localEngine->flat());
    em = sq*y + xm;
      } while( em < 0.0 );
      em = std::floor(em);
      t = 0.9*(1.0 + y*y)* std::exp(em*alxm - gammln(em + 1.0) - g1);
    } while( localEngine->flat() > t );
  }
  else {
    em = xm + std::sqrt(xm) * normal (localEngine.get());   // mf 1/13/06
    if ( static_cast<long>(em) < 0 ) 
      em = static_cast<long>(xm) >= 0 ? xm : getMaxMean();
  }    
  status[0] = sq; status[1] = alxm; status[2] = g1;
  return long(em);
}

fireArray() [1/2]

void CLHEP::RandPoisson::fireArray	(	const int	size,
		long *	vect
	)

Definition at line 271 of file RandPoisson.cc.

{
  for( long* v = vect; v != vect + size; ++v )
    *v = fire( defaultMean );
}

fireArray() [2/2]

void CLHEP::RandPoisson::fireArray	(	const int	size,
		long *	vect,
		double	mean
	)

Definition at line 277 of file RandPoisson.cc.

{
  for( long* v = vect; v != vect + size; ++v )
    *v = fire( m1 );
}

get()

std::istream & CLHEP::RandPoisson::get ( std::istream &  is )

virtual

Reimplemented from CLHEP::HepRandom.

Reimplemented in CLHEP::RandPoissonQ.

Definition at line 304 of file RandPoisson.cc.

                                                {
  std::string inName;
  is >> inName;
  if (inName != name()) {
    is.clear(std::ios::badbit | is.rdstate());
    std::cerr << "Mismatch when expecting to read state of a "
              << name() << " distribution\n"
          << "Name found was " << inName
          << "\nistream is left in the badbit state\n";
    return is;
  }
  if (possibleKeywordInput(is, "Uvec", meanMax)) {
    std::vector<unsigned long> t(2);
    is >> meanMax     >> t[0] >> t[1]; meanMax     = DoubConv::longs2double(t); 
    is >> defaultMean >> t[0] >> t[1]; defaultMean = DoubConv::longs2double(t); 
    is >> status[0]   >> t[0] >> t[1]; status[0]   = DoubConv::longs2double(t); 
    is >> status[1]   >> t[0] >> t[1]; status[1]   = DoubConv::longs2double(t); 
    is >> status[2]   >> t[0] >> t[1]; status[2]   = DoubConv::longs2double(t); 
    is >> oldm        >> t[0] >> t[1]; oldm        = DoubConv::longs2double(t); 
    return is;
  }
  // is >> meanMax encompassed by possibleKeywordInput
  is >> defaultMean >> status[0] >> status[1] >> status[2];
  return is;
}

Referenced by CLHEP::RandPoissonQ::get().

getLocalEngine()

HepRandomEngine * CLHEP::RandPoisson::getLocalEngine ( )

inlineprotected

Referenced by CLHEP::RandPoissonQ::fire().

getMaxMean()

static double CLHEP::RandPoisson::getMaxMean ( )

inlinestaticprotected

Definition at line 103 of file RandPoisson.h.

{return meanMax_st;}

Referenced by fire(), and shoot().

getOldMean()

static double CLHEP::RandPoisson::getOldMean ( )

inlinestaticprotected

Definition at line 101 of file RandPoisson.h.

{return oldm_st;}

Referenced by shoot().

getPStatus()

static double * CLHEP::RandPoisson::getPStatus ( )

inlinestaticprotected

Definition at line 107 of file RandPoisson.h.

{return status_st;}

Referenced by shoot().

name()

std::string CLHEP::RandPoisson::name ( ) const

virtual

Reimplemented from CLHEP::HepRandom.

Reimplemented in CLHEP::RandPoissonQ.

Definition at line 37 of file RandPoisson.cc.

{return "RandPoisson";}

Referenced by get(), and put().

operator()() [1/2]

double CLHEP::RandPoisson::operator() ( )

virtual

Reimplemented from CLHEP::HepRandom.

Reimplemented in CLHEP::RandPoissonQ.

Definition at line 48 of file RandPoisson.cc.

                               {
  return double(fire( defaultMean ));
}

operator()() [2/2]

double CLHEP::RandPoisson::operator()

(

double

mean

)

Definition at line 52 of file RandPoisson.cc.

                                            {
  return double(fire( mean ));
}

put()

std::ostream & CLHEP::RandPoisson::put ( std::ostream &  os ) const

virtual

Reimplemented from CLHEP::HepRandom.

Reimplemented in CLHEP::RandPoissonQ.

Definition at line 283 of file RandPoisson.cc.

                                                      {
  int pr=os.precision(20);
  std::vector<unsigned long> t(2);
  os << " " << name() << "\n";
  os << "Uvec" << "\n";
  t = DoubConv::dto2longs(meanMax);
  os << meanMax << " " << t[0] << " " << t[1] << "\n";
  t = DoubConv::dto2longs(defaultMean);
  os << defaultMean << " " << t[0] << " " << t[1] << "\n";
  t = DoubConv::dto2longs(status[0]);
  os << status[0] << " " << t[0] << " " << t[1] << "\n";
  t = DoubConv::dto2longs(status[1]);
  os << status[1] << " " << t[0] << " " << t[1] << "\n";
  t = DoubConv::dto2longs(status[2]);
  os << status[2] << " " << t[0] << " " << t[1] << "\n";
  t = DoubConv::dto2longs(oldm);
  os << oldm << " " << t[0] << " " << t[1] << "\n";
  os.precision(pr);
  return os;
}

Referenced by CLHEP::RandPoissonQ::put().

setOldMean()

static void CLHEP::RandPoisson::setOldMean ( double  val )

inlinestaticprotected

Definition at line 105 of file RandPoisson.h.

{oldm_st = val;}

Referenced by shoot().

setPStatus()

static void CLHEP::RandPoisson::setPStatus ( double  sq, double  alxm, double  g1  )

inlinestaticprotected

Definition at line 109 of file RandPoisson.h.

                                                            {
    status_st[0] = sq; status_st[1] = alxm; status_st[2] = g1;
  }

Referenced by shoot().

shoot() [1/2]

long CLHEP::RandPoisson::shoot ( double  mean = 1.0 )

static

Definition at line 93 of file RandPoisson.cc.

                                 {
 
// Returns as a floating-point number an integer value that is a random
// deviation drawn from a Poisson distribution of mean xm, using flat()
// as a source of uniform random numbers.
// (Adapted from Numerical Recipes in C)
 
  double em, t, y;
  double sq, alxm, g1;
  double om = getOldMean();
  HepRandomEngine* anEngine = HepRandom::getTheEngine();
 
  double* pstatus = getPStatus();
  sq = pstatus[0];
  alxm = pstatus[1];
  g1 = pstatus[2];
 
  if( xm == -1 ) return 0;
  if( xm < 12.0 ) {
    if( xm != om ) {
      setOldMean(xm);
      g1 = std::exp(-xm);
    }
    em = -1;
    t = 1.0;
    do {
      em += 1.0;
      t *= anEngine->flat();
    } while( t > g1 );
  }
  else if ( xm < getMaxMean() ) {
    if ( xm != om ) {
      setOldMean(xm);
      sq = std::sqrt(2.0*xm);
      alxm = std::log(xm);
      g1 = xm*alxm - gammln(xm + 1.0);
    }
    do {
      do {
    y = std::tan(CLHEP::pi*anEngine->flat());
    em = sq*y + xm;
      } while( em < 0.0 );
      em = std::floor(em);
      t = 0.9*(1.0 + y*y)* std::exp(em*alxm - gammln(em + 1.0) - g1);
    } while( anEngine->flat() > t );
  }
  else {
    em = xm + std::sqrt(xm) * normal (anEngine);    // mf 1/13/06
    if ( static_cast<long>(em) < 0 ) 
      em = static_cast<long>(xm) >= 0 ? xm : getMaxMean();
  }    
  setPStatus(sq,alxm,g1);
  return long(em);
}

Referenced by shootArray().

shoot() [2/2]

long CLHEP::RandPoisson::shoot ( HepRandomEngine *  anEngine, double  mean = 1.0  )

static

Definition at line 154 of file RandPoisson.cc.

                                                            {
 
// Returns as a floating-point number an integer value that is a random
// deviation drawn from a Poisson distribution of mean xm, using flat()
// of a given Random Engine as a source of uniform random numbers.
// (Adapted from Numerical Recipes in C)
 
  double em, t, y;
  double sq, alxm, g1;
  double om = getOldMean();
 
  double* pstatus = getPStatus();
  sq = pstatus[0];
  alxm = pstatus[1];
  g1 = pstatus[2];
 
  if( xm == -1 ) return 0;
  if( xm < 12.0 ) {
    if( xm != om ) {
      setOldMean(xm);
      g1 = std::exp(-xm);
    }
    em = -1;
    t = 1.0;
    do {
      em += 1.0;
      t *= anEngine->flat();
    } while( t > g1 );
  }
  else if ( xm < getMaxMean() ) {
    if ( xm != om ) {
      setOldMean(xm);
      sq = std::sqrt(2.0*xm);
      alxm = std::log(xm);
      g1 = xm*alxm - gammln(xm + 1.0);
    }
    do {
      do {
    y = std::tan(CLHEP::pi*anEngine->flat());
    em = sq*y + xm;
      } while( em < 0.0 );
      em = std::floor(em);
      t = 0.9*(1.0 + y*y)* std::exp(em*alxm - gammln(em + 1.0) - g1);
    } while( anEngine->flat() > t );
  }
  else {
    em = xm + std::sqrt(xm) * normal (anEngine);    // mf 1/13/06
    if ( static_cast<long>(em) < 0 ) 
      em = static_cast<long>(xm) >= 0 ? xm : getMaxMean();
  }    
  setPStatus(sq,alxm,g1);
  return long(em);
}

shootArray() [1/2]

void CLHEP::RandPoisson::shootArray ( const int  size, long *  vect, double  mean = 1.0  )

static

Definition at line 148 of file RandPoisson.cc.

{
  for( long* v = vect; v != vect + size; ++v )
    *v = shoot(m1);
}

shootArray() [2/2]

void CLHEP::RandPoisson::shootArray ( HepRandomEngine *  anEngine, const int  size, long *  vect, double  mean = 1.0  )

static

Definition at line 208 of file RandPoisson.cc.

{
  for( long* v = vect; v != vect + size; ++v )
    *v = shoot(anEngine,m1);
}

Member Data Documentation

defaultMean

double CLHEP::RandPoisson::defaultMean

protected

Definition at line 99 of file RandPoisson.h.

Referenced by fire(), CLHEP::RandPoissonQ::fire(), fireArray(), CLHEP::RandPoissonQ::fireArray(), get(), operator()(), and put().

meanMax

double CLHEP::RandPoisson::meanMax

protected

Definition at line 98 of file RandPoisson.h.

Referenced by fire(), get(), and put().

---

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

• RandPoisson.h
• RandPoisson.cc