DualRand

Exclusive or of a feedback shift register and integer congruence random number generator. The feedback shift register uses offsets 127 and 97. The integer congruence generator uses a different multiplier for each stream. The multipliers are chosen to give full period and maximum "potency" for modulo 2^32. The period of the combined random number generator is 2^159 - 2^32, and the sequences are different for each stream (not just started in a different place).

Author

See also

Engines: HepRandomEngine, DRand48Engine , 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/DualRand.h"

class DualRand: public HepRandomEngine

Public Member Functions

Constructors

DualRand()

DualRand(long seed)

DualRand(HepInt rowIndex, HepInt colIndex)

DualRand(std::istream& is)

Copy constructor

DualRand(const DualRand & p)

Destructor

virtual ~DualRand()

Conversion operators

operator HepFloat()

Flat value, without worrying about filling bits

operator unsigned int()

32-bit flat value, quickest of all

=

DualRand & operator=(const DualRand & p)

Assignment

flat

HepDouble flat()

Returns a pseudo random number between 0 and 1 (excluding the end points)

flatArray

void flatArray(const HepInt size, HepDouble* vect)

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

restoreStatus

void restoreStatus(const char filename[] = "DualRand.conf")

Reads from named file the last saved engine status and restores it.

saveStatus

void saveStatus(const char filename[] = "DualRand.conf") const

Saves on named file the current engine status.

setSeed

void setSeed(long seed, HepInt)

Sets the state of the algorithm according to seed.

setSeeds

void setSeeds(const long * seeds, HepInt)

Sets the state of the algorithm according to the zero-terminated array of seeds.

showStatus

void showStatus() const

Dumps the current engine status on the screen.

Non-Member Functions

<<

std::ostream & operator<< (std::ostream & os, const DualRand & e)

Output to a stream.

>>

std::istream & operator>> (std::istream & is, DualRand & e)

Input from a stream.

Example