1 // $Id: JamesRandom.h,v 1.5 2010/06/16 17:24:53 garren Exp $ 2 // -*- C++ -*- 3 // 4 // ----------------------------------------------------------------------- 5 // HEP Random 6 // --- HepJamesRandom --- 7 // class header file 8 // ----------------------------------------------------------------------- 9 // This file is part of Geant4 (simulation toolkit for HEP). 10 // 11 // HepJamesRandom implements the algorithm by Marsaglia-Zaman RANMAR 12 // described in "F.James, Comp. Phys. Comm. 60 (1990) 329" and implemented 13 // in FORTRAN77 as part of the MATHLIB HEP library for pseudo-random 14 // numbers generation. 15 // This is the default random engine invoked by each distribution unless 16 // the user sets a different one. 17 18 // ======================================================================= 19 // Gabriele Cosmo - Created: 5th September 1995 20 // - Minor corrections: 31st October 1996 21 // - Added methods for engine status: 19th November 1996 22 // - setSeed(), setSeeds() now have default dummy argument 23 // set to zero: 11th July 1997 24 // J.Marraffino - Added stream operators and related constructor. 25 // Added automatic seed selection from seed table and 26 // engine counter: 16th Feb 1998 27 // Ken Smith - Added conversion operators: 6th Aug 1998 28 // V. Innocente - changed pointers to indices 3 may 2000 29 // Mark Fischler - Methods for distrib. instance save/restore 12/8/04 30 // Mark Fischler methods for anonymous save/restore 12/27/04 31 // ======================================================================= 32 33 #ifndef HepJamesRandom_h 34 #define HepJamesRandom_h 1 35 36 #include "CLHEP/Random/defs.h" 37 #include "CLHEP/Random/RandomEngine.h" 38 39 namespace CLHEP { 40 41 /** 42 * @author 43 * @ingroup random 44 */ 45 class HepJamesRandom: public HepRandomEngine { 46 47 public: 48 49 HepJamesRandom(std::istream& is); 50 HepJamesRandom(); 51 HepJamesRandom(long seed); 52 HepJamesRandom(int rowIndex, int colIndex); 53 virtual ~HepJamesRandom(); 54 // Constructor and destructor. 55 56 double flat(); 57 // Returns a pseudo random number between 0 and 1 58 // (excluding the end points) 59 60 void flatArray (const int size, double* vect); 61 // Fills the array "vect" of specified size with flat random values. 62 63 void setSeed(long seed, int dum=0); 64 // Sets the state of the algorithm according to seed. 65 66 void setSeeds(const long * seeds, int dum=0); 67 // Sets the state of the algorithm according to the zero terminated 68 // array of seeds. Only the first seed is used. 69 70 void saveStatus( const char filename[] = "JamesRand.conf" ) const; 71 // Saves on file JamesRand.conf the current engine status. 72 73 void restoreStatus( const char filename[] = "JamesRand.conf" ); 74 // Reads from file JamesRand.conf the last saved engine status 75 // and restores it. 76 77 void showStatus() const; 78 // Dumps the engine status on the screen. 79 80 operator double(); 81 // Returns same as flat() 82 operator float(); 83 // less precise flat, faster if possible 84 operator unsigned int(); 85 // 32-bit flat, but slower than double or float. 86 87 virtual std::ostream & put (std::ostream & os) const; 88 virtual std::istream & get (std::istream & is); 89 static std::string beginTag ( ); 90 virtual std::istream & getState ( std::istream & is ); 91 92 std::string name() const; engineName()93 static std::string engineName() {return "HepJamesRandom";} 94 95 std::vector<unsigned long> put () const; 96 bool get (const std::vector<unsigned long> & v); 97 bool getState (const std::vector<unsigned long> & v); 98 99 static const unsigned int VECTOR_STATE_SIZE = 202; 100 101 private: 102 103 // Members defining the current status of the generator. 104 double u[97]; 105 double c, cd, cm; 106 int i97, j97; 107 }; 108 109 } // namespace CLHEP 110 111 #ifdef ENABLE_BACKWARDS_COMPATIBILITY 112 // backwards compatibility will be enabled ONLY in CLHEP 1.9 113 using namespace CLHEP; 114 #endif 115 116 #endif 117