d2/d36/JamesRandom_8h_source.html

// -*- C++ -*-

//

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

//                             HEP Random

//                        --- HepJamesRandom ---

//                          class header file

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

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

//

// HepJamesRandom implements the algorithm by Marsaglia-Zaman RANMAR

// described in "F.James, Comp. Phys. Comm. 60 (1990) 329" and implemented

// in FORTRAN77 as part of the MATHLIB HEP library for pseudo-random

// numbers generation.

// This is the default random engine invoked by each distribution unless

// the user sets a different one.


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

// Gabriele Cosmo - Created: 5th September 1995

//                - Minor corrections: 31st October 1996

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

//                - setSeed(), setSeeds() now have default dummy argument

//                  set to zero: 11th July 1997

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

//                  Added automatic seed selection from seed table and

//                  engine counter: 16th Feb 1998

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

// V. Innocente   - changed pointers to indices     3 may 2000

// Mark Fischler  - Methods for distrib. instance save/restore 12/8/04

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

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


#ifndef HepJamesRandom_h

#define HepJamesRandom_h 1


#include "CLHEP/Random/RandomEngine.h"


namespace CLHEP {


class HepJamesRandom: public HepRandomEngine {


public:


  HepJamesRandom(std::istream& is);

  HepJamesRandom();

  HepJamesRandom(long seed);

  HepJamesRandom(int rowIndex, int colIndex);

  virtual ~HepJamesRandom();

  // Constructor and destructor.


  double flat();

  // 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 dum=0);

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


  void setSeeds(const long * seeds, int dum=0);

  // 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[] = "JamesRand.conf" ) const;

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


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

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

  // and restores it.


  void showStatus() const;

  // Dumps the engine status on the screen.


  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 "HepJamesRandom";}


  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 = 202;


private:


  // Members defining the current status of the generator.

  double u[97];

  double c, cd, cm;

  int i97, j97;

};


}  // namespace CLHEP


#endif