HepRandomEngine

HepRandomEngine is an abstract class defining the interface for each random engine. It implements the getSeed() and getSeeds() methods which return the initial seed value and the initial array of seeds respectively. It defines seven pure virtual functions: flat(), flatArray(), setSeed(), setSeeds(), saveStatus(), restoreStatus() and showStatus(), which are implemented by the concrete random engines each one inheriting from this abstract class.

Many concrete random engines can be defined and added to the structure, simply making them inheriting from HepRandomEngine and definingf the six functions flat(), flatArray(), setSeed(), setSeeds(), saveStatus(), restoreStatus() and showStatus() in such a way that flat() and flatArray() return double random values ranging between ]0,1[.

All the random engines have a default seed value already set but they can be instantiated with a different seed value set up by the user.

Author

See also

Engines: DRand48Engine , DualRand HepJamesRandom Hurd160Engine Hurd288Engine MTwistEngine RandEngine RanecuEngine RanluxEngine Ranlux64Engine RanshiEngine TripleRand

Distributions: HepRandom, RandBinomial RandBreitWigner RandChiSquare RandExponential RandFlat RandGamma RandGauss RandGeneral RandPoisson RandStudentT

Declaration

#include "CLHEP/Random/RandomEngine.h"

class HepRandomEngine

Public Member Functions

Constructor

HepRandomEngine()

Destructor

virtual ~HepRandomEngine()

Conversion operators

virtual operator HepDouble()

Returns same as flat()

virtual operator HepFloat()

Less precise flat, faster if possible

virtual operator unsigned int()

32-bit int flat, faster if possible

==

inline HepBoolean operator==(const HepRandomEngine& engine)

Overloaded equality operator.

!=

inline HepBoolean operator!=(const HepRandomEngine& engine)

Overloaded inequality operator.

flat

virtual HepDouble flat() = 0

Should return a pseudo random number between 0 and 1, excluding the end points.

flatArray

virtual void flatArray(const HepInt size, HepDouble* vect) = 0

Fills an array vect of specified size with flat random values.

getSeed

long getSeed() const

Gets the current seed.

getSeeds

const long* getSeeds() const

Gets the current array of seeds.

restoreStatus

virtual void restoreStatus(const char filename[] = "Config.conf") = 0

Should read from a file (specific to the instantiated engine in use) and restore the last saved engine configuration.

saveStatus

virtual void saveStatus(const char filename[] = "Config.conf") const = 0

Should save on a file specific to the instantiated engine in use the current status.

setSeed

virtual void setSeed(long seed, HepInt) = 0

Should initialise the status of the algorithm according to seed.

setSeeds

virtual void setSeeds(const long * seeds, HepInt) = 0

Should initialise the status of the algorithm according to the zero terminated array of seeds. It is allowed to ignore one or many seeds in this array.

showStatus

virtual void showStatus() const = 0

Should dump the current engine status on the screen.