| Geant4 Cross Reference |
1 // -*- C++ -*- 1 // -*- C++ -*-
2 // 2 //
3 // ------------------------------------------- 3 // -----------------------------------------------------------------------
4 // HEP Random 4 // HEP Random
5 // --- MTwistEngine --- 5 // --- MTwistEngine ---
6 // class header file 6 // class header file
7 // ------------------------------------------- 7 // -----------------------------------------------------------------------
8 // A "fast, compact, huge-period generator" ba 8 // A "fast, compact, huge-period generator" based on M. Matsumoto and
9 // T. Nishimura, "Mersenne Twister: A 623-dime 9 // T. Nishimura, "Mersenne Twister: A 623-dimensionally equidistributed
10 // uniform pseudorandom number generator", to 10 // uniform pseudorandom number generator", to appear in ACM Trans. on
11 // Modeling and Computer Simulation. It is a 11 // Modeling and Computer Simulation. It is a twisted GFSR generator
12 // with a Mersenne-prime period of 2^19937-1, 12 // with a Mersenne-prime period of 2^19937-1, uniform on open interval (0,1)
13 // For further information, see http://www.mat 13 // For further information, see http://www.math.keio.ac.jp/~matumoto/emt.html
14 // =========================================== 14 // =======================================================================
15 // Ken Smith - Started initial draft: 14t 15 // Ken Smith - Started initial draft: 14th Jul 1998
16 // - Optimized to get pow() out 16 // - Optimized to get pow() out of flat() method: 21st Jul
17 // - Added conversion operators 17 // - Added conversion operators: 6th Aug 1998
18 // M Fischler - Changes in way powers of two 18 // M Fischler - Changes in way powers of two are kept: 16-Sep-1998
19 // Mark Fischler - Methods for distrib. insta 19 // Mark Fischler - Methods for distrib. instance save/restore 12/8/04
20 // Mark Fischler methods for anonymous save 20 // Mark Fischler methods for anonymous save/restore 12/27/04
21 // =========================================== 21 // =======================================================================
22 22
23 #ifndef MTwistEngine_h 23 #ifndef MTwistEngine_h
24 #define MTwistEngine_h 24 #define MTwistEngine_h
25 25
26 #include "CLHEP/Random/RandomEngine.h" 26 #include "CLHEP/Random/RandomEngine.h"
27 27
28 namespace CLHEP { 28 namespace CLHEP {
29 29
30 /** 30 /**
31 * @author 31 * @author
32 * @ingroup random 32 * @ingroup random
33 */ 33 */
34 class MTwistEngine : public HepRandomEngine { 34 class MTwistEngine : public HepRandomEngine {
35 35
36 public: 36 public:
37 37
38 MTwistEngine(); 38 MTwistEngine();
39 MTwistEngine( long seed ); 39 MTwistEngine( long seed );
40 MTwistEngine( int rowIndex, int colIndex ); 40 MTwistEngine( int rowIndex, int colIndex );
41 MTwistEngine( std::istream & is ); 41 MTwistEngine( std::istream & is );
42 virtual ~MTwistEngine(); 42 virtual ~MTwistEngine();
43 // Constructors and destructor. 43 // Constructors and destructor.
44 44
45 double flat(); 45 double flat();
46 // Returns a pseudo random number between 0 46 // Returns a pseudo random number between 0 and 1 (excluding the end points).
47 47
48 void flatArray(const int size, double* vect) 48 void flatArray(const int size, double* vect);
49 // Fills an array "vect" of specified size w 49 // Fills an array "vect" of specified size with flat random values.
50 50
51 void setSeed(long seed, int); 51 void setSeed(long seed, int);
52 // Sets the state of the algorithm according 52 // Sets the state of the algorithm according to seed.
53 53
54 void setSeeds(const long * seeds, int); 54 void setSeeds(const long * seeds, int);
55 // Sets the state of the algorithm according 55 // Sets the state of the algorithm according to the zero terminated
56 // array of seeds. It is allowed to ignore o 56 // array of seeds. It is allowed to ignore one or many seeds in this array.
57 57
58 void saveStatus( const char filename[] = "MT 58 void saveStatus( const char filename[] = "MTwist.conf") const;
59 // Saves the current engine status in the na 59 // Saves the current engine status in the named file
60 60
61 void restoreStatus( const char filename[] = 61 void restoreStatus( const char filename[] = "MTwist.conf" );
62 // Reads from named file the the last saved 62 // Reads from named file the the last saved engine status and restores it.
63 63
64 void showStatus() const; 64 void showStatus() const;
65 // Dumps the current engine status on the sc 65 // Dumps the current engine status on the screen.
66 66
67 operator double(); // Returns same as 67 operator double(); // Returns same as flat()
68 operator float(); // returns flat, wi 68 operator float(); // returns flat, without worrying about filling bits
69 operator unsigned int(); // 32-bit flat, qui 69 operator unsigned int(); // 32-bit flat, quickest of all
70 70
71 virtual std::ostream & put (std::ostream & o 71 virtual std::ostream & put (std::ostream & os) const;
72 virtual std::istream & get (std::istream & i 72 virtual std::istream & get (std::istream & is);
73 static std::string beginTag ( ); 73 static std::string beginTag ( );
74 virtual std::istream & getState ( std::istre 74 virtual std::istream & getState ( std::istream & is );
75 75
76 std::string name() const; 76 std::string name() const;
77 static std::string engineName() {return "MTw 77 static std::string engineName() {return "MTwistEngine";}
78 78
79 std::vector<unsigned long> put () const; 79 std::vector<unsigned long> put () const;
80 bool get (const std::vector<unsigned long> & 80 bool get (const std::vector<unsigned long> & v);
81 bool getState (const std::vector<unsigned lo 81 bool getState (const std::vector<unsigned long> & v);
82 82
83 static const unsigned int VECTOR_STATE_SIZE 83 static const unsigned int VECTOR_STATE_SIZE = 626;
84 84
85 private: 85 private:
86 86
87 unsigned int mt[624]; 87 unsigned int mt[624];
88 int count624; 88 int count624;
89 89
90 enum{ NminusM = 227, M = 397, N = 624}; 90 enum{ NminusM = 227, M = 397, N = 624};
91 91
92 }; // MTwistEngine 92 }; // MTwistEngine
93 93
94 } // namespace CLHEP 94 } // namespace CLHEP
95 95
96 #endif // MTwistEngine_h 96 #endif // MTwistEngine_h
97 97