d2/deb/MTwistEngine_8h_source.html

// -*- C++ -*-

//

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

//                             HEP Random

//                        --- MTwistEngine ---

//                          class header file

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

// A "fast, compact, huge-period generator" based on M. Matsumoto and

// T. Nishimura, "Mersenne Twister: A 623-dimensionally equidistributed

// uniform pseudorandom number generator", to appear in ACM Trans. on

// Modeling and Computer Simulation.  It is a twisted GFSR generator

// with a Mersenne-prime period of 2^19937-1, uniform on open interval (0,1)

// For further information, see http://www.math.keio.ac.jp/~matumoto/emt.html

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

// Ken Smith      - Started initial draft: 14th Jul 1998

//                - Optimized to get pow() out of flat() method: 21st Jul

//                - Added conversion operators:  6th Aug 1998

// M Fischler   - Changes in way powers of two are kept: 16-Sep-1998

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

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

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


#ifndef MTwistEngine_h

#define MTwistEngine_h


#include "CLHEP/Random/RandomEngine.h"


namespace CLHEP {


class MTwistEngine : public HepRandomEngine {


public:


  MTwistEngine();

  MTwistEngine( long seed );

  MTwistEngine( int rowIndex, int colIndex );

  MTwistEngine( std::istream & is );

  virtual ~MTwistEngine();

  // Constructors 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 an array "vect" of specified size with flat random values.


  void setSeed(long seed, int);

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


  void setSeeds(const long * seeds, int);

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

  // array of seeds. It is allowed to ignore one or many seeds in this array.


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

  // Saves the current engine status in the named file


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

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


  void showStatus() const;

  // Dumps the current engine status on the screen.


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

  operator float();        // returns flat, without worrying about filling bits

  operator unsigned int(); // 32-bit flat, quickest of all


  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 "MTwistEngine";}


  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 = 626;


private:


  unsigned int mt[624];

  int count624;


  enum{ NminusM = 227, M = 397, N = 624};


}; // MTwistEngine


}  // namespace CLHEP


#endif // MTwistEngine_h