ThePEG::UseRandom Class Reference

This UseRandom class keeps a static stack of RandomGenerator objects which can be used anywhere by any class. More...

#include <UseRandom.h>

List of all members.

Public Member Functions
	UseRandom ()
	Default constructor does nothing.
	UseRandom (const UseRandom &)
	Copy-constructor does nothing.
	UseRandom (const RanGenPtr &r)
	Construct a new object specifying a new RandomGenerator, r, to be used during this objects lifetime.
	~UseRandom ()
	The destructor removing the RandomGenerator specified in the constructor from the stack.
Static Public Member Functions
static RandomGenerator &	current ()
	Return a reference to the currently chosen RandomGenerator object.
static double	rnd ()
	Return a pointer to the currently chosen RandomGenerator object.
static RandomGenerator::RndVector	rndvec (int n)
	Return n simple flat random number (from the current RandomGenerator object) in the range ]0,1[.
template<typename Unit>
static Unit	rnd (Unit xu)
	Return a simple flat random number (from the current RandomGenerator object) in the range ]0,xu[.
template<typename Unit>
static Unit	rnd (Unit xl, Unit xu)
	Return a simple flat random number (from the current RandomGenerator object) in the range ]xl,xu[.
static bool	rndbool (double p=0.5)
	Return a true with probability p (default 0.5).
static bool	rndbool (double p1, double p2)
	Return a true with probability p1/(p1+p2).
static int	rndsign (double p1, double p2, double p3)
	Return -1, 0, or 1 with relative probabilities p1, p2, p3.
static int	rnd2 (double p0, double p1)
	Return an integer with probability p/(p0+p1).
static int	rnd3 (double p0, double p1, double p2)
	Return an integer with probability p/(p0+p1+p2).
static int	rnd4 (double p0, double p1, double p2, double p3)
	Return an integer/ with probability p(p0+p1+p2+p3).
static long	irnd (long xu=2)
	Return a simple flat random integrer number in the range [0,xu[.
static long	irnd (long xl, long xu)
	Return a simple flat random integrer number in the range [xl,xu[.
static double	rndExp ()
	Return a number between zero and infinity, distributed according to .
template<typename Unit>
static Unit	rndExp (Unit mean)
	Return a number between zero and infinity, distributed according to where is the mean value.
static double	rndGauss ()
	Return a number distributed according to a Gaussian distribution with zero mean and unit variance.
template<typename Unit>
static 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>
static 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>
static 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.
template<typename Unit>
static 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>
static 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.
static long	rndPoisson (double mean)
	Return a non-negative number generated according to a Poissonian distribution with a given mean.
Private Member Functions
UseRandom &	operator= (const UseRandom &)
	Private and non-existent assignment operator.
Private Attributes
bool	randomPushed
	True if this object is responsible for pushing a RandomGenerator onto the stack.
Static Private Attributes
static vector< RanGenPtr >	theRandomStack
	The stack of RandomGenerators requested.

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Detailed Description

This UseRandom class keeps a static stack of RandomGenerator objects which can be used anywhere by any class.

When an EventGenerator is initialized or run it adds a RandomGenerator object to the stack which can be used by any other object being initialized or run through the static functions of the UseRandom class. If someone needs to use an alternative RandomGenerator object a new UseRandom object can be constructed with a pointer to the desired RandomGenerator object as argument and that object will the be used by the static UseRandom functions until the UseRandom object is destructed.

See also:

RandomGenerator

EventGenerator

Definition at line 33 of file UseRandom.h.

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Member Function Documentation

static double ThePEG::UseRandom::rnd

(

)

[inline, static]

Return a pointer to the currently chosen RandomGenerator object.

Return a simple flat random number (from the current RandomGenerator object) in the range ]0,1[.

Definition at line 82 of file UseRandom.h.

References current(), and ThePEG::RandomGenerator::rnd().

Referenced by irnd().

template<typename Unit>

static Unit ThePEG::UseRandom::rndBW	(	Unit	mean,
		Unit	gamma,
		Unit	cut
	)			[inline, static]

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 209 of file UseRandom.h.

References current(), and ThePEG::RandomGenerator::rndBW().

template<typename Unit>

static Unit ThePEG::UseRandom::rndRelBW	(	Unit	mean,
		Unit	gamma,
		Unit	cut
	)			[inline, static]

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 229 of file UseRandom.h.

References current(), and ThePEG::RandomGenerator::rndRelBW().

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

• UseRandom.h