d4/d5f/RanluxEngine_8h_source.html

// -*- C++ -*-

//

// -----------------------------------------------------------------------

//                             HEP Random

//                        --- RanluxEngine ---

//                          class header file

// -----------------------------------------------------------------------

// This file is part of Geant4 (simulation toolkit for HEP).

//

// The algorithm for this random engine has been taken from the original

// implementation in FORTRAN by Fred James as part of the MATHLIB HEP

// library.

// The initialisation is carried out using a Multiplicative Congruential

// generator using formula constants of L'Ecuyer as described in "F.James,

// Comp. Phys. Comm. 60 (1990) 329-344".


// =======================================================================

// Adeyemi Adesanya - Created: 6th November 1995

// Gabriele Cosmo - Adapted & Revised: 22nd November 1995

// Adeyemi Adesanya - Added setSeeds() method: 2nd February 1996

// Gabriele Cosmo - Added flatArray() method: 8th February 1996

//                - Added methods for engine status: 19th November 1996

//                - Added default luxury value for setSeed()

//                  and setSeeds(): 21st July 1997

// J.Marraffino   - Added stream operators and related constructor.

//                  Added automatic seed selection from seed table and

//                  engine counter: 14th Feb 1998

// Ken Smith      - Added conversion operators:  6th Aug 1998

// Mark Fischler    Methods put, get for instance save/restore 12/8/04

// Mark Fischler    methods for anonymous save/restore 12/27/04

// =======================================================================


#ifndef RanluxEngine_h

#define RanluxEngine_h 1


#include "CLHEP/Random/RandomEngine.h"


namespace CLHEP {


class RanluxEngine : public HepRandomEngine {


public:


  RanluxEngine( std::istream& is );

  RanluxEngine();

  RanluxEngine( long seed, int lux = 3 );

  RanluxEngine( int rowIndex, int colIndex, int lux );

  virtual ~RanluxEngine();

  // Constructors and destructor


// Luxury level is set in the same way as the original FORTRAN routine.

//  level 0  (p=24): equivalent to the original RCARRY of Marsaglia

//           and Zaman, very long period, but fails many tests.

//  level 1  (p=48): considerable improvement in quality over level 0,

//           now passes the gap test, but still fails spectral test.

//  level 2  (p=97): passes all known tests, but theoretically still

//           defective.

//  level 3  (p=223): DEFAULT VALUE.  Any theoretically possible

//           correlations have very small chance of being observed.

//  level 4  (p=389): highest possible luxury, all 24 bits chaotic.


  double flat();

  // It returns a pseudo random number between 0 and 1,

  // excluding the end points.


  void flatArray (const int size, double* vect);

  // Fills the array "vect" of specified size with flat random values.


  void setSeed(long seed, int lux=3);

  // Sets the state of the algorithm according to seed.


  void setSeeds(const long * seeds, int lux=3);

  // Sets the state of the algorithm according to the zero terminated

  // array of seeds. Only the first seed is used.


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

  // Saves on file Ranlux.conf the current engine status.


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

  // Reads from file Ranlux.conf the last saved engine status

  // and restores it.


  void showStatus() const;

  // Dumps the engine status on the screen.


  int getLuxury() const { return luxury; }

  // Gets the luxury level.


  operator double();       // Returns same as flat()

  operator float();        // less precise flat, faster if possible

  operator unsigned int(); // 32-bit flat, but slower than double or float


  virtual std::ostream & put (std::ostream & os) const;

  virtual std::istream & get (std::istream & is);

  static  std::string beginTag ( );

  virtual std::istream & getState ( std::istream & is );


  std::string name() const;

  static std::string engineName() {return "RanluxEngine";}


  std::vector<unsigned long> put () const;

  bool get (const std::vector<unsigned long> & v);

  bool getState (const std::vector<unsigned long> & v);


  static const unsigned int VECTOR_STATE_SIZE = 31;


private:


  int nskip, luxury;

  float float_seed_table[24];

  int i_lag,j_lag;

  float carry;

  int count24;

  static const int int_modulus = 0x1000000;

};


}  // namespace CLHEP


#endif