CLHEP::RandGeneral Class Reference

#include <RandGeneral.h>

Inheritance diagram for CLHEP::RandGeneral:

Collaboration diagram for CLHEP::RandGeneral:

Public Member Functions
	RandGeneral (const double *aProbFunc, int theProbSize, int IntType=0)
	RandGeneral (HepRandomEngine &anEngine, const double *aProbFunc, int theProbSize, int IntType=0)
	RandGeneral (HepRandomEngine *anEngine, const double *aProbFunc, int theProbSize, int IntType=0)
virtual	~RandGeneral ()
double	shoot ()
void	shootArray (const int size, double *vect)
double	shoot (HepRandomEngine *anEngine)
void	shootArray (HepRandomEngine *anEngine, const int size, double *vect)
double	fire ()
void	fireArray (const int size, double *vect)
double	operator() ()
std::ostream &	put (std::ostream &os) const
std::istream &	get (std::istream &is)
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)

Static Public Member Functions
static std::string	distributionName ()
Static Public Member Functions inherited from CLHEP::HepRandom
static void	setTheSeed (long seed, int lux=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 ()

Private Member Functions
void	prepareTable (const double *aProbFunc)
void	useFlatDistribution ()
double	mapRandom (double rand) const

Private Attributes
std::shared_ptr< HepRandomEngine >	localEngine
std::vector< double >	theIntegralPdf
int	nBins
double	oneOverNbins
int	InterpolationType

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

Detailed Description

Author

Definition at line 39 of file RandGeneral.h.

Constructor & Destructor Documentation

RandGeneral() [1/3]

CLHEP::RandGeneral::RandGeneral	(	const double *	aProbFunc,
		int	theProbSize,
		int	IntType = 0
	)

Definition at line 64 of file RandGeneral.cc.

  : HepRandom(),
    localEngine(HepRandom::getTheEngine(), do_nothing_deleter()),
    nBins(theProbSize), 
    InterpolationType(IntType)
{
  prepareTable(aProbFunc);
}

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RandGeneral() [2/3]

CLHEP::RandGeneral::RandGeneral	(	HepRandomEngine &	anEngine,
		const double *	aProbFunc,
		int	theProbSize,
		int	IntType = 0
	)

Definition at line 75 of file RandGeneral.cc.

: HepRandom(),
  localEngine(&anEngine, do_nothing_deleter()), 
  nBins(theProbSize),
  InterpolationType(IntType)
{
  prepareTable(aProbFunc);
}

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RandGeneral() [3/3]

CLHEP::RandGeneral::RandGeneral	(	HepRandomEngine *	anEngine,
		const double *	aProbFunc,
		int	theProbSize,
		int	IntType = 0
	)

Definition at line 87 of file RandGeneral.cc.

: HepRandom(),
  localEngine(anEngine), 
  nBins(theProbSize),
  InterpolationType(IntType)
{
  prepareTable(aProbFunc);
}

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~RandGeneral()

CLHEP::RandGeneral::~RandGeneral ( )

virtual

Definition at line 172 of file RandGeneral.cc.

                          {
}

Member Function Documentation

distributionName()

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

inlinestatic

Definition at line 125 of file RandGeneral.h.

{return "RandGeneral";}  

engine()

HepRandomEngine & CLHEP::RandGeneral::engine ( )

virtual

Reimplemented from CLHEP::HepRandom.

Definition at line 57 of file RandGeneral.cc.

{return *localEngine;}

fire()

double CLHEP::RandGeneral::fire

(

)

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fireArray()

void CLHEP::RandGeneral::fireArray	(	const int	size,
		double *	vect
	)

Definition at line 238 of file RandGeneral.cc.

{
   int i;

   for (i=0; i<size; ++i) {
      vect[i] = fire();
   }
}

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get()

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

virtual

Reimplemented from CLHEP::HepRandom.

Definition at line 264 of file RandGeneral.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", nBins)) {
    std::vector<unsigned long> t(2);
    is >> nBins >> oneOverNbins >> InterpolationType;
    is >> t[0] >> t[1]; oneOverNbins = DoubConv::longs2double(t); 
    theIntegralPdf.resize(nBins+1);
    for (unsigned int i=0; i<theIntegralPdf.size(); ++i) {
      is >> theIntegralPdf[i] >> t[0] >> t[1];
      theIntegralPdf[i] = DoubConv::longs2double(t); 
    }
    return is;
  }
  // is >> nBins encompassed by possibleKeywordInput
  is >> oneOverNbins >> InterpolationType;
  theIntegralPdf.resize(nBins+1);
  for (unsigned int i=0; i<theIntegralPdf.size(); ++i) is >> theIntegralPdf[i];
  return is;
}

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mapRandom()

double CLHEP::RandGeneral::mapRandom ( double  rand ) const

private

Definition at line 180 of file RandGeneral.cc.

                                               {
//
// Private method to take the random (however it is created) and map it
// according to the distribution.
//

  int nbelow = 0;     // largest k such that I[k] is known to be <= rand
  int nabove = nBins;     // largest k such that I[k] is known to be >  rand
  int middle;
  
  while (nabove > nbelow+1) {
    middle = (nabove + nbelow+1)>>1;
    if (rand >= theIntegralPdf[middle]) {
      nbelow = middle;
    } else {
      nabove = middle;
    }
  } // after this loop, nabove is always nbelow+1 and they straddle rad:
    assert ( nabove == nbelow+1 );
    assert ( theIntegralPdf[nbelow] <= rand );
    assert ( theIntegralPdf[nabove] >= rand );  
        // If a defective engine produces rand=1, that will 
        // still give sensible results so we relax the > rand assertion

  if ( InterpolationType == 1 ) {

    return nbelow * oneOverNbins;

  } else {

    double binMeasure = theIntegralPdf[nabove] - theIntegralPdf[nbelow];
    // binMeasure is always aProbFunc[nbelow], 
    // but we don't have aProbFunc any more so we subtract.

    if ( binMeasure == 0 ) { 
    // rand lies right in a bin of measure 0.  Simply return the center
    // of the range of that bin.  (Any value between k/N and (k+1)/N is 
    // equally good, in this rare case.)
        return (nbelow + .5) * oneOverNbins;
    }

    double binFraction = (rand - theIntegralPdf[nbelow]) / binMeasure;

    return (nbelow + binFraction) * oneOverNbins;
  }

} // mapRandom(rand)

name()

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

virtual

Reimplemented from CLHEP::HepRandom.

Definition at line 56 of file RandGeneral.cc.

{return "RandGeneral";}

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operator()()

double CLHEP::RandGeneral::operator() ( )

virtual

Reimplemented from CLHEP::HepRandom.

prepareTable()

void CLHEP::RandGeneral::prepareTable ( const double *  aProbFunc )

private

Definition at line 99 of file RandGeneral.cc.

                                                      {
//
// Private method called only by constructors.  Prepares theIntegralPdf.
//
  if (nBins < 1) {
    std::cerr << 
    "RandGeneral constructed with no bins - will use flat distribution\n";
    useFlatDistribution();
    return;
  }

  theIntegralPdf.resize(nBins+1);
  theIntegralPdf[0] = 0;
  int ptn;
  double weight;

  for ( ptn = 0; ptn<nBins; ++ptn ) {
    weight = aProbFunc[ptn];
    if ( weight < 0 ) {
    // We can't stomach negative bin contents, they invalidate the 
    // search algorithm when the distribution is fired.
      std::cerr << 
    "RandGeneral constructed with negative-weight bin " << ptn <<
    " = " << weight << " \n   -- will substitute 0 weight \n";
      weight = 0;
    }
    // std::cout << ptn << "  " << weight << "  " << theIntegralPdf[ptn] << "\n";
    theIntegralPdf[ptn+1] = theIntegralPdf[ptn] + weight;
  } 

  if ( theIntegralPdf[nBins] <= 0 ) {
    std::cerr << 
      "RandGeneral constructed nothing in bins - will use flat distribution\n";
    useFlatDistribution();
    return;
  }

  for ( ptn = 0; ptn < nBins+1; ++ptn ) {
    theIntegralPdf[ptn] /= theIntegralPdf[nBins];
    // std::cout << ptn << "  " << theIntegralPdf[ptn] << "\n";
  }

  // And another useful variable is ...
  oneOverNbins = 1.0 / nBins;

  // One last chore:

  if ( (InterpolationType != 0) && (InterpolationType != 1) ) {
    std::cerr << 
      "RandGeneral does not recognize IntType " << InterpolationType 
      << "\n Will use type 0 (continuous linear interpolation \n";
    InterpolationType = 0;
  }

} // prepareTable()

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put()

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

virtual

Reimplemented from CLHEP::HepRandom.

Definition at line 247 of file RandGeneral.cc.

                                                      {
  int pr=os.precision(20);
  std::vector<unsigned long> t(2);
  os << " " << name() << "\n";
  os << "Uvec" << "\n";
  os << nBins << " " << oneOverNbins << " " << InterpolationType << "\n";    
  t = DoubConv::dto2longs(oneOverNbins);
  os << t[0] << " " << t[1] << "\n";
  assert (static_cast<int>(theIntegralPdf.size())==nBins+1);
  for (unsigned int i=0; i<theIntegralPdf.size(); ++i) {
    t = DoubConv::dto2longs(theIntegralPdf[i]);
    os << theIntegralPdf[i] << " " << t[0] << " " << t[1] << "\n";
  }
  os.precision(pr);
  return os;
}

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shoot() [1/2]

double CLHEP::RandGeneral::shoot ( )

inline

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shoot() [2/2]

double CLHEP::RandGeneral::shoot

(

HepRandomEngine *

anEngine

)

shootArray() [1/2]

void CLHEP::RandGeneral::shootArray ( const int  size, double *  vect  )

inline

shootArray() [2/2]

void CLHEP::RandGeneral::shootArray	(	HepRandomEngine *	anEngine,
		const int	size,
		double *	vect
	)

Definition at line 228 of file RandGeneral.cc.

{
   int i;

   for (i=0; i<size; ++i) {
     vect[i] = shoot(anEngine);
   }
}

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useFlatDistribution()

void CLHEP::RandGeneral::useFlatDistribution ( )

private

Definition at line 155 of file RandGeneral.cc.

                                      {
//
// Private method called only by prepareTables in case of user error. 
//
    nBins = 1;
    theIntegralPdf.resize(2);
    theIntegralPdf[0] = 0;
    theIntegralPdf[1] = 1;
    oneOverNbins = 1.0;
    return;

} // UseFlatDistribution()

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Member Data Documentation

InterpolationType

int CLHEP::RandGeneral::InterpolationType

private

Definition at line 135 of file RandGeneral.h.

localEngine

std::shared_ptr<HepRandomEngine> CLHEP::RandGeneral::localEngine

private

Definition at line 131 of file RandGeneral.h.

nBins

int CLHEP::RandGeneral::nBins

private

Definition at line 133 of file RandGeneral.h.

oneOverNbins

double CLHEP::RandGeneral::oneOverNbins

private

Definition at line 134 of file RandGeneral.h.

theIntegralPdf

std::vector<double> CLHEP::RandGeneral::theIntegralPdf

private

Definition at line 132 of file RandGeneral.h.

---

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

• RandGeneral.h
• RandGeneral.cc