RandomGenerator is an interface to the CLHEP::RandomEngine classes. More...

#include <RandomGenerator.h>

Inheritance diagram for ThePEG::RandomGenerator:

[legend]

Public Types
typedef vector< double >	RndVector
	A vector of doubles. More...

typedef RndVector::size_type	size_type
	The size_type of RndVector. More...

Public Types inherited from ThePEG::InterfacedBase
enum	InitState { initializing = -1, uninitialized = 0, initialized = 1, runready = 2 }
	Enumeration reflecting the state of an InterfacedBase object. More...

Public Types inherited from ThePEG::Pointer::ReferenceCounted
typedef unsigned int	CounterType
	The integer type used for counting.

Public Member Functions
virtual void	setSeed (long seed)=0
	Reset the underlying random engine with the given seed. More...

gsl_rng *	getGslInterface ()
	Return a gsl_rng interface to this random generator.

Standard constructors and destructors.
	RandomGenerator ()
	Default constructor.

	RandomGenerator (const RandomGenerator &)
	Copy-constructor.

virtual	~RandomGenerator ()
	Destructor.

Functions to return random numbers.
double	rnd ()
	Return a (possibly cached) flat random number in the interval .

template<typename Unit >
Unit	rnd (Unit b)
	Return a flat random number in the interval .

template<typename Unit >
Unit	rnd (Unit a, Unit b)
	Return a flat random number in the interval .

RndVector	rndvec (int n)
	Return n flat random number in the interval .

double	operator() ()
	Return a (possibly cached) flat random number in the interval .

double	operator() (double N)
	Return a (possibly cached) flat integer random number in the interval . More...

long	operator() (long N)
	Return a (possibly cached) flat integer random number in the interval .

bool	rndbool (double p=0.5)
	Return a true with probability p. More...

bool	prndbool (double p=0.5)
	Return a true with probability p. More...

bool	rndbool (double p1, double p2)
	Return a true with probability p1/(p1+p2). More...

bool	prndbool (double p1, double p2)
	Return a true with probability p1/(p1+p2). More...

int	rndsign (double p1, double p2, double p3)
	Return -1, 0, or 1 with relative probabilities p1, p2, p3. More...

int	prndsign (double p1, double p2, double p3)
	Return -1, 0, or 1 with relative probabilities p1, p2, p3. More...

int	rnd2 (double p0, double p1)
	Return an integer with probability p /(p0+p1). More...

int	rnd3 (double p0, double p1, double p2)
	Return an integer with probability p /(p0+p1+p2). More...

int	rnd4 (double p0, double p1, double p2, double p3)
	Return an integer/ with probability p (p0+p1+p2+p3). More...

int	rnd5 (double p0, double p1, double p2, double p3, double p4)
	Return an integer/ with probability p (p0+p1+p2+p3+p4). More...

double	rndExp ()
	Return a number between zero and infinity, distributed according to .

template<typename Unit >
Unit	rndExp (Unit mean)
	Return a number between zero and infinity, distributed according to $e^-{x/\mu}$ where $\mu$ is the mean value.

void	rndGaussTwoNumbers (double &randomNumberOne, double &randomNumberTwo)
	Return two numbers distributed according to a Gaussian distribution with zero mean and unit variance. More...

double	rndGauss ()
	Return a number distributed according to a Gaussian distribution with zero mean and unit variance. More...

template<typename Unit >
Unit	rndGauss (Unit sigma, Unit mean=Unit())
	Return a number distributed according to a Gaussian distribution with a given standard deviation, sigma, and a given mean.

template<typename Unit >
void	rndGaussTwoNumbers (Unit &randomNumberOne, Unit &randomNumberTwo, Unit sigma, Unit mean=Unit())
	Return two numbers distributed according to a Gaussian distribution with a given standard deviation, sigma, and a given mean.

template<typename Unit >
Unit	rndBW (Unit mean, Unit gamma)
	Return a positive number distributed according to a non-relativistic Breit-Wigner with a given width, gamma, and a given mean.

template<typename Unit >
Unit	rndBW (Unit mean, Unit gamma, Unit cut)
	Return a positive number distributed according to a non-relativistic Breit-Wigner with a given width, gamma, and a given mean. More...

template<typename Unit >
Unit	rndRelBW (Unit mean, Unit gamma)
	Return a positive number distributed according to a relativistic Breit-Wigner with a given width, gamma, and a given mean.

template<typename Unit >
Unit	rndRelBW (Unit mean, Unit gamma, Unit cut)
	Return a positive number distributed according to a relativistic Breit-Wigner with a given width, gamma, and a given mean. More...

long	rndPoisson (double mean)
	Return a non-negative number generated according to a Poissonian distribution with a given mean. More...

Access the cached random numbers from the underlying engine.
void	push_back (double r)
	Give back a partly unused random number. More...

void	pop_back ()
	Discard the next random number in the cache.

void	flush ()
	Discard all random numbers in the cache. More...

template<typename OutputIterator >
void	rnd (OutputIterator o, size_type n)
	Generate n random numbers between 0 and 1 and put them in the output iterator.

Functions used by the persistent I/O system.
void	persistentOutput (PersistentOStream &os) const
	Function used to write out object persistently. More...

void	persistentInput (PersistentIStream &is, int version)
	Function used to read in object persistently. More...

Public Member Functions inherited from ThePEG::Interfaced
virtual	~Interfaced ()
	Empty virtual destructor.

virtual bool	defaultInit ()
	Functions which are to be used during the actual event generation, after the setup is complete. More...

PPtr	getParticle (PID) const
	Create a new Particle instance given a id number.

PDPtr	getParticleData (PID) const
	Return a pointer to the ParticleData object corresponding to the given id number.

bool	used () const
	Returns true if this object has actally been used.

void	useMe () const
	Should be called to indicate that this object has actually been used.

tEGPtr	generator () const
	Return a pointer to the EventGenerator controlling the run. More...

void	persistentOutput (PersistentOStream &os) const
	Function used to write out object persistently. More...

void	persistentInput (PersistentIStream &is, int version)
	Function used to read in object persistently. More...

Public Member Functions inherited from ThePEG::InterfacedBase
virtual	~InterfacedBase ()
	The virtual (empty) destructor;.

string	fullName () const
	Returns the full name of this object including its path, e.g. More...

string	name () const
	Returns the name of this object, without the path.

string	path () const
	Returns the path to this object including the trailing '/'. More...

string	comment () const
	Returns a comment assigned to this object.

void	setup (istream &is)
	Read setup info from a standard istream is. More...

virtual IBPtr	fullclone () const
	Return a full clone of this object possibly doing things to the clone to make it sane.

virtual void	debugme () const
	Print out debugging information for this object on std::cerr. More...

void	update ()
	Calls the doupdate() function with recursion prevention.

void	init ()
	Calls the doinit() function with recursion prevention.

virtual bool	preInitialize () const
	Return true if this object needs to be initialized before all other objects (except those for which this function also returns true). More...

void	initrun ()
	Calls the doinitrun() function with recursion prevention.

void	finish ()
	Calls the dofinish() function with recursion prevention.

void	touch ()
	This function should be called every time something in this object has changed in a way that a sanity check with update() is needed.

void	reset ()
	Set the state of this object to uninitialized.

void	clear ()
	Calls reset() and unTouch().

InitState	state () const
	Return the state of initialization of this object.

bool	locked () const
	Return true if the BaseRepository is not allowed to change the state of this object.

bool	touched () const
	Return true if the state of this object has been changed since the last call to update().

void	persistentOutput (PersistentOStream &os) const
	Function used to write out object persistently. More...

void	persistentInput (PersistentIStream &is, int version)
	Function used to read in object persistently. More...

Public Member Functions inherited from ThePEG::Base
virtual	~Base ()
	The virtual destructor.

void	debug () const
	Print out debugging information for this object on std::cerr. More...

Public Member Functions inherited from ThePEG::Pointer::ReferenceCounted
CounterType	referenceCount () const
	Return the reference count.

Public Member Functions inherited from ThePEG::Named
	Named (const string &newName=string())
	Constructor with name.

	Named (const Named &)=default
	Explicit default copy-constructor (too avoid compiler warnings)

const string &	name () const
	Return name.

bool	operator== (const Named &other) const
	Test for equality.

bool	operator< (const Named &other) const
	Lexicographical comparison.

Static Public Member Functions
static void	Init ()
	Standard Init function used to initialize the interface.

Static Public Member Functions inherited from ThePEG::Interfaced
static void	Init ()
	Standard Init function.

Static Public Member Functions inherited from ThePEG::InterfacedBase
static void	Init ()
	Standard Init function.

Static Public Member Functions inherited from ThePEG::Base
static void	Init ()
	The standard Init function used to initialize the interfaces. More...

Protected Member Functions
virtual void	doinit ()
	Initializes this random generator. More...

void	setSize (size_type newSize)
	Utility function for the interface.

virtual void	fill ()=0
	Fill the cache with random numbers.

Protected Member Functions inherited from ThePEG::Interfaced
void	reporeg (IBPtr object, string name) const
	Register the given object in the Repository with the given name in a subdirectory with the same name as this object. More...

template<typename PtrT >
bool	setDefaultReference (PtrT &ptr, string classname, string objectname)
	If the pointer, ptr, to an object is not set, create an object of class classname and register it with the Repository with the given objectname in a sib-directory with the same name as this object.

	Interfaced ()
	Protected default constructor.

	Interfaced (const string &newName)
	Protected constructor taking a name as argument.

	Interfaced (const Interfaced &i)
	Protected copy-constructor.

void	setGenerator (tEGPtr generator)
	Protected function to reset the generator pointer, required for automatic decayer generation in Herwig++ BSM models.

Protected Member Functions inherited from ThePEG::InterfacedBase
virtual IBPtr	clone () const =0
	Return a simple clone of this object. More...

	InterfacedBase ()
	Protected default constructor.

	InterfacedBase (string newName)
	Protected constructor with the name given as argument.

	InterfacedBase (const InterfacedBase &i)
	Protected copy-constructor.

virtual void	readSetup (istream &is)
	Read setup info from a standard istream is. More...

virtual void	doupdate ()
	Check sanity of the object during the setup phase. More...

virtual void	doinitrun ()
	Initialize this object. More...

virtual void	dofinish ()
	Finalize this object. More...

virtual IVector	getReferences ()
	Return a vector of all pointers to Interfaced objects used in this object. More...

virtual void	rebind (const TranslationMap &)
	Rebind pointer to other Interfaced objects. More...

Protected Member Functions inherited from ThePEG::Pointer::ReferenceCounted
	ReferenceCounted ()
	Default constructor.

	ReferenceCounted (const ReferenceCounted &)
	Copy-constructor.

ReferenceCounted &	operator= (const ReferenceCounted &)
	Assignment.

Protected Member Functions inherited from ThePEG::Named
const Named &	operator= (const Named &other)
	Assignment.

const string &	name (const string &newName)
	Set new name.

Protected Attributes
RndVector	theNumbers
	A vector of cached numbers.

RndVector::iterator	nextNumber
	Iterator pointing to the next number to be extracted.

size_type	theSize
	The size of the cache.

long	theSeed
	The seed to initialize the random generator with.

double	savedGauss
	A saved Gaussian random number.

bool	gaussSaved
	Indicate the precense of a saved Gaussian random number.

gsl_rng *	gsl
	A pinter to a gsl_rng interface to this generator.

Private Member Functions
RandomGenerator &	operator= (const RandomGenerator &)=delete
	Private and non-existent assignment operator.

Static Private Attributes
static ClassDescription< RandomGenerator >	initRandomGenerator
	Describe a concrete class with persistent data. More...

Additional Inherited Members
Public Attributes inherited from ThePEG::Pointer::ReferenceCounted
const unsigned long	uniqueId
	The unique ID. More...

Static Protected Member Functions inherited from ThePEG::Interfaced
static void	registerRepository (IBPtr)
	Register an Interfaced object with the Repository.

static void	registerRepository (IBPtr, string newName)
	Register an Interfaced object with the Repository, giving it a name.

Detailed Description

RandomGenerator is an interface to the CLHEP::RandomEngine classes.

To avoid excessive virtual function calls, the RandomGenerator caches random numbers generated by the engine which are then retrieved by the non-virtual inlined rnd() method.

Sub-classes of RandomGenerator should be used to implement a particular random engine.

RandomGenerator only provides a flat distribution between 0 and

Any other distribution can be achieved using the CLHEP random classes using the engine returned from the randomGenerator() method.

See also: The interfaces defined for RandomGenerator.; UseRandom

Definition at line 37 of file RandomGenerator.h.

Member Typedef Documentation

◆ RndVector

typedef vector<double> ThePEG::RandomGenerator::RndVector

A vector of doubles.

Definition at line 42 of file RandomGenerator.h.

◆ size_type

typedef RndVector::size_type ThePEG::RandomGenerator::size_type

The size_type of RndVector.

Definition at line 45 of file RandomGenerator.h.

Member Function Documentation

◆ doinit()

virtual void ThePEG::RandomGenerator::doinit ( )

protectedvirtual

Initializes this random generator.

This should be done first of all before the initialization of any other object associated with an event generator.

Reimplemented from ThePEG::InterfacedBase.

Referenced by rnd().

◆ flush()

void ThePEG::RandomGenerator::flush ( )

inline

Discard all random numbers in the cache.

Typically used after the internal random engine has been reinitialized for some reason.

Definition at line 352 of file RandomGenerator.h.

References gaussSaved, nextNumber, and theNumbers.

◆ operator()()

double ThePEG::RandomGenerator::operator() ( double N )

inline

Return a (possibly cached) flat integer random number in the interval $[0,N[$ .

Function was introduced since otherwise operator()() is used if a double is given resulting in a $]0,1[$ distribution.

Definition at line 119 of file RandomGenerator.h.

References rnd().

◆ persistentInput()

void ThePEG::RandomGenerator::persistentInput	(	PersistentIStream &	is,
		int	version
	)

Function used to read in object persistently.

Parameters

is	the persistent input stream read from.
version	the version number of the object when written.

Referenced by rnd().

◆ persistentOutput()

void ThePEG::RandomGenerator::persistentOutput ( PersistentOStream & os ) const

Function used to write out object persistently.

Parameters

os	the persistent output stream written to.

Referenced by rnd().

◆ prndbool() [1/2]

bool ThePEG::RandomGenerator::prndbool ( double p = 0.5 )

Return a true with probability p.

Uses rnd(). Also uses push_back(double).

Referenced by rndbool().

◆ prndbool() [2/2]

bool ThePEG::RandomGenerator::prndbool	(	double	p1,
		double	p2
	)

inline

Return a true with probability p1/(p1+p2).

Uses rnd(). Also uses push_back(double).

Definition at line 150 of file RandomGenerator.h.

References prndbool(), prndsign(), and rndsign().

Referenced by prndbool().

◆ prndsign()

int ThePEG::RandomGenerator::prndsign	(	double	p1,
		double	p2,
		double	p3
	)

Return -1, 0, or 1 with relative probabilities p1, p2, p3.

Uses rnd(). Also uses push_back(double).

Referenced by prndbool().

◆ push_back()

void ThePEG::RandomGenerator::push_back ( double r )

inline

Give back a partly unused random number.

This is typically used when generating integral random numbers. In eg. rndbool(double p) a random number r is drawn and if it is less than p true is returned, but r is still a good random number in the interval ]0,p[. Hence r/p is still a good random number in the interval ]0,1[ and this is then pushed back into the cache and is used by the next call to rnd(). Note that the resulting random number is of lesser quality, and successive calls to push_back() should be avoided. To ensure a highest quality random number random number in the next call to rnd(), pop_back() should be used.

Definition at line 336 of file RandomGenerator.h.

References nextNumber, and theNumbers.

◆ rnd2()

int ThePEG::RandomGenerator::rnd2	(	double	p0,
		double	p1
	)

inline

Return an integer $i$ with probability p $i$ /(p0+p1).

Uses rnd().

Definition at line 168 of file RandomGenerator.h.

References rndbool().

Referenced by ThePEG::UseRandom::rnd2().

◆ rnd3()

int ThePEG::RandomGenerator::rnd3	(	double	p0,
		double	p1,
		double	p2
	)

inline

Return an integer $i$ with probability p $i$ /(p0+p1+p2).

Uses rnd().

Definition at line 176 of file RandomGenerator.h.

References rnd4(), rnd5(), and rndsign().

Referenced by ThePEG::UseRandom::rnd3().

◆ rnd4()

int ThePEG::RandomGenerator::rnd4	(	double	p0,
		double	p1,
		double	p2,
		double	p3
	)

Return an integer/ $i$ with probability p $i$ (p0+p1+p2+p3).

Uses rnd().

Referenced by rnd3(), and ThePEG::UseRandom::rnd4().

◆ rnd5()

int ThePEG::RandomGenerator::rnd5	(	double	p0,
		double	p1,
		double	p2,
		double	p3,
		double	p4
	)

Return an integer/ $i$ with probability p $i$ (p0+p1+p2+p3+p4).

Uses rnd().

Referenced by rnd3(), and ThePEG::UseRandom::rnd5().

◆ rndbool() [1/2]

bool ThePEG::RandomGenerator::rndbool ( double p = 0.5 )

inline

Return a true with probability p.

Uses rnd().

Definition at line 130 of file RandomGenerator.h.

References prndbool(), and rnd().

Referenced by ThePEG::UseRandom::prndbool(), rnd2(), and ThePEG::UseRandom::rndbool().

◆ rndbool() [2/2]

bool ThePEG::RandomGenerator::rndbool	(	double	p1,
		double	p2
	)

inline

Return a true with probability p1/(p1+p2).

Uses rnd().

Definition at line 144 of file RandomGenerator.h.

References rndbool().

Referenced by rndbool().

◆ rndBW()

template<typename Unit >

Unit ThePEG::RandomGenerator::rndBW	(	Unit	mean,
		Unit	gamma,
		Unit	cut
	)

inline

Return a positive number distributed according to a non-relativistic Breit-Wigner with a given width, gamma, and a given mean.

The distribution is cut-off so that the number is between mean - cut and mean + cut

Definition at line 278 of file RandomGenerator.h.

References rnd().

◆ rndGauss()

double ThePEG::RandomGenerator::rndGauss ( )

inline

Return a number distributed according to a Gaussian distribution with zero mean and unit variance.

A second number is cached and returned the next time. This function calls the rndGaussTwoNumbers function which returns two numbers at once.

Definition at line 227 of file RandomGenerator.h.

References gaussSaved, rndGaussTwoNumbers(), and savedGauss.

Referenced by ThePEG::UseRandom::rndGauss(), and rndGauss().

◆ rndGaussTwoNumbers()

void ThePEG::RandomGenerator::rndGaussTwoNumbers	(	double &	randomNumberOne,
		double &	randomNumberTwo
	)

inline

Return two numbers distributed according to a Gaussian distribution with zero mean and unit variance.

Parameters

[out]	First	random number
[out]	Second	random number

Definition at line 214 of file RandomGenerator.h.

References ThePEG::Constants::pi, and rnd().

Referenced by rndGauss(), and rndGaussTwoNumbers().

◆ rndPoisson()

long ThePEG::RandomGenerator::rndPoisson ( double mean )

Return a non-negative number generated according to a Poissonian distribution with a given mean.

Warning: the method implemented is very slow for large mean and large return values. For this reason the maximum return value is given by nmax.

Referenced by ThePEG::UseRandom::rndPoisson(), and rndRelBW().

◆ rndRelBW()

template<typename Unit >

Unit ThePEG::RandomGenerator::rndRelBW	(	Unit	mean,
		Unit	gamma,
		Unit	cut
	)

inline

Return a positive number distributed according to a relativistic Breit-Wigner with a given width, gamma, and a given mean.

The distribution is cut-off so that the number is between mean - cut and mean + cut

Definition at line 302 of file RandomGenerator.h.

References rnd(), rndPoisson(), and ThePEG::sqr().

◆ rndsign()

int ThePEG::RandomGenerator::rndsign	(	double	p1,
		double	p2,
		double	p3
	)

Return -1, 0, or 1 with relative probabilities p1, p2, p3.

Uses rnd().

Referenced by prndbool(), ThePEG::UseRandom::prndsign(), rnd3(), and ThePEG::UseRandom::rndsign().

◆ setSeed()

virtual void ThePEG::RandomGenerator::setSeed ( long seed )

pure virtual

Reset the underlying random engine with the given seed.

If the seed is set to -1 a standard seed will be used.

Implemented in ThePEG::StandardRandom.

Member Data Documentation

◆ initRandomGenerator

ClassDescription<RandomGenerator> ThePEG::RandomGenerator::initRandomGenerator

staticprivate

Describe a concrete class with persistent data.

Note that the class should in principle be abstract.

Definition at line 458 of file RandomGenerator.h.

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

RandomGenerator.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Static Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ RndVector

◆ size_type

Member Function Documentation

◆ doinit()

◆ flush()

◆ operator()()

◆ persistentInput()

◆ persistentOutput()

◆ prndbool() [1/2]

◆ prndbool() [2/2]

◆ prndsign()

◆ push_back()

◆ rnd2()

◆ rnd3()

◆ rnd4()

◆ rnd5()

◆ rndbool() [1/2]

◆ rndbool() [2/2]

◆ rndBW()

◆ rndGauss()

◆ rndGaussTwoNumbers()

◆ rndPoisson()

◆ rndRelBW()

◆ rndsign()

◆ setSeed()

Member Data Documentation

◆ initRandomGenerator