| Geant4 Cross Reference |
1 // -*- C++ -*- 1
2 //
3 // -------------------------------------------
4 // HEP Random
5 // --- MTwistEngine ---
6 // class header file
7 // -------------------------------------------
8 // A "fast, compact, huge-period generator" ba
9 // T. Nishimura, "Mersenne Twister: A 623-dime
10 // uniform pseudorandom number generator", to
11 // Modeling and Computer Simulation. It is a
12 // with a Mersenne-prime period of 2^19937-1,
13 // For further information, see http://www.mat
14 // ===========================================
15 // Ken Smith - Started initial draft: 14t
16 // - Optimized to get pow() out
17 // - Added conversion operators
18 // M Fischler - Changes in way powers of two
19 // Mark Fischler - Methods for distrib. insta
20 // Mark Fischler methods for anonymous save
21 // ===========================================
22
23 #ifndef MTwistEngine_h
24 #define MTwistEngine_h
25
26 #include "CLHEP/Random/RandomEngine.h"
27
28 namespace CLHEP {
29
30 /**
31 * @author
32 * @ingroup random
33 */
34 class MTwistEngine : public HepRandomEngine {
35
36 public:
37
38 MTwistEngine();
39 MTwistEngine( long seed );
40 MTwistEngine( int rowIndex, int colIndex );
41 MTwistEngine( std::istream & is );
42 virtual ~MTwistEngine();
43 // Constructors and destructor.
44
45 double flat();
46 // Returns a pseudo random number between 0
47
48 void flatArray(const int size, double* vect)
49 // Fills an array "vect" of specified size w
50
51 void setSeed(long seed, int);
52 // Sets the state of the algorithm according
53
54 void setSeeds(const long * seeds, int);
55 // Sets the state of the algorithm according
56 // array of seeds. It is allowed to ignore o
57
58 void saveStatus( const char filename[] = "MT
59 // Saves the current engine status in the na
60
61 void restoreStatus( const char filename[] =
62 // Reads from named file the the last saved
63
64 void showStatus() const;
65 // Dumps the current engine status on the sc
66
67 operator double(); // Returns same as
68 operator float(); // returns flat, wi
69 operator unsigned int(); // 32-bit flat, qui
70
71 virtual std::ostream & put (std::ostream & o
72 virtual std::istream & get (std::istream & i
73 static std::string beginTag ( );
74 virtual std::istream & getState ( std::istre
75
76 std::string name() const;
77 static std::string engineName() {return "MTw
78
79 std::vector<unsigned long> put () const;
80 bool get (const std::vector<unsigned long> &
81 bool getState (const std::vector<unsigned lo
82
83 static const unsigned int VECTOR_STATE_SIZE
84
85 private:
86
87 unsigned int mt[624];
88 int count624;
89
90 enum{ NminusM = 227, M = 397, N = 624};
91
92 }; // MTwistEngine
93
94 } // namespace CLHEP
95
96 #endif // MTwistEngine_h
97