| Geant4 Cross Reference |
1 // -*- C++ -*-
2 //
3 // -----------------------------------------------------------------------
4 // HEP Random
5 // --- RanecuEngine ---
6 // class header file
7 // -----------------------------------------------------------------------
8 // This file is part of Geant4 (simulation toolkit for HEP).
9 //
10 // RANECU Random Engine - algorithm originally written in FORTRAN77
11 // as part of the MATHLIB HEP library.
12 // The initialisation is carried out using a Multiplicative Congruential
13 // generator using formula constants of L'Ecuyer as described in "F.James,
14 // Comp. Phys. Comm. 60 (1990) 329-344".
15 // Seeds are taken from a seed table given an index, the getSeed() method
16 // returns the current index in the seed table, the getSeeds() method
17 // returns a pointer to the couple of seeds stored in the local table of
18 // seeds at the current index.
19
20 // =======================================================================
21 // Gabriele Cosmo - Created: 2nd February 1996
22 // - Minor corrections: 31st October 1996
23 // - Added methods for engine status: 19th November 1996
24 // - setSeed() now has default dummy argument
25 // set to zero: 11th July 1997
26 // - Added default index to setSeeds(): 16th Oct 1997
27 // J.Marraffino - Added stream operators and related constructor.
28 // Added automatic seed selection from seed table and
29 // engine counter: 16th Feb 1998
30 // Ken Smith - Added conversion operators: 6th Aug 1998
31 // Mark Fischler Methods for distrib. instance save/restore 12/8/04
32 // Mark Fischler methods for anonymous save/restore 12/27/04
33 // =======================================================================
34
35 #ifndef RanecuEngine_h
36 #define RanecuEngine_h 1
37
38 #include "CLHEP/Random/RandomEngine.h"
39
40 namespace CLHEP {
41
42 /**
43 * @author <Gabriele.Cosmo@cern.ch>
44 * @ingroup random
45 */
46 class RanecuEngine : public HepRandomEngine {
47
48 public:
49
50 RanecuEngine(std::istream& is);
51 RanecuEngine();
52 RanecuEngine(int index);
53 virtual ~RanecuEngine();
54 // Constructors 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 an array "vect" of specified size with flat random values.
62
63 void setIndex (long index);
64 // Sets the state of the algorithm according to "index", the position
65 // in the local table of seeds.
66
67 void setSeed (long index, int dum=0);
68 // Resets the state of the algorithm according to "index", the position
69 // in the static table of seeds stored in HepRandom.
70
71 void setSeeds (const long* seeds, int index=-1);
72 // Sets the state of the algorithm according to the array of seeds
73 // "seeds" containing two seed values to be stored in the local table at
74 // "index" position.
75
76 void saveStatus( const char filename[] = "Ranecu.conf" ) const;
77 // Saves on file Ranecu.conf the current engine status.
78
79 void restoreStatus( const char filename[] = "Ranecu.conf" );
80 // Reads from file Ranecu.conf the last saved engine status
81 // and restores it.
82
83 void showStatus() const;
84 // Dumps the engine status on the screen.
85
86 operator double();
87 // Returns same as flat()
88 operator float();
89 // less precise flat, faster if possible
90 operator unsigned int();
91 // 32-bit int flat, faster in this case
92
93 virtual std::ostream & put (std::ostream & os) const;
94 virtual std::istream & get (std::istream & is);
95 static std::string beginTag ( );
96 virtual std::istream & getState ( std::istream & is );
97
98 std::string name() const;
99 static std::string engineName() {return "RanecuEngine";}
100
101 std::vector<unsigned long> put () const;
102 bool get (const std::vector<unsigned long> & v);
103 bool getState (const std::vector<unsigned long> & v);
104
105 protected:
106
107 // Suggested L'ecuyer coefficients for portable 32 bits generators.
108
109 static const int ecuyer_a = 40014;
110 static const int ecuyer_b = 53668;
111 static const int ecuyer_c = 12211;
112 static const int ecuyer_d = 40692;
113 static const int ecuyer_e = 52774;
114 static const int ecuyer_f = 3791;
115 static const int shift1 = 2147483563;
116 static const int shift2 = 2147483399;
117
118 static const unsigned int VECTOR_STATE_SIZE = 4;
119
120 private:
121
122 // private method used to mitigate the effects of using a lookup table
123 void further_randomize (int seq, int col, int index, int modulus);
124
125 // Members defining the current state of the generator.
126
127 static const int maxSeq = 215;
128 long table[215][2];
129 int seq;
130
131 };
132
133 } // namespace CLHEP
134
135 #endif
136