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DualRand.h
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1 // -*- C++ -*-
2 //
3 // -----------------------------------------------------------------------
4 // Hep Random
5 // --- DualRand ---
6 // class header file
7 // -----------------------------------------------------------------------
8 //
9 // Canopy random number generator DualRand
10 // Re-written as C++ routine for 32-bit ints MF 1/26/98
11 //
12 // Exclusive or of a feedback shift register and integer congruence
13 // random number generator. The feedback shift register uses offsets
14 // 127 and 97. The integer congruence generator uses a different
15 // multiplier for each stream. The multipliers are chosen to give
16 // full period and maximum "potency" for modulo 2^32. The period of
17 // the combined random number generator is 2^159 - 2^32, and the
18 // sequences are different for each stream (not just started in a
19 // different place).
20 //
21 // =======================================================================
22 // Canopy random number generator DualRand.
23 // Doug Toussaint 5/25/88
24 // Optimized by GMH 7/26/88
25 // Optimized by GMH 7/26/88
26 // Repaired by GMH 12/1/88 to update modular congruence state
27 // Put into ranlib by GMH 6/23/89
28 // Re-written as C++ routine for 32-bit ints MF 1/26/98
29 // Re-written for CLHEP package KLS 6/04/98
30 // Removed pow() from flat method for speed KLS 7/21/98
31 // Ken Smith - Added conversion operators: 6th Aug 1998
32 // Mark Fischler methods for distrib. instance save/restore 12/8/04
33 // Mark Fischler methods for anonymous save/restore 12/27/04
34 // Mark Fischler - methods for vector save/restore 3/7/05
35 // =======================================================================
36 
37 
38 #ifndef DualRand_h
39 #define DualRand_h
40 
41 #include "CLHEP/Random/RandomEngine.h"
42 
43 namespace CLHEP {
44 
49 class DualRand: public HepRandomEngine {
50 
51 public:
52 
53  DualRand();
54  DualRand(long seed);
55  DualRand(std::istream & is);
56  DualRand(int rowIndex, int colIndex);
57  virtual ~DualRand();
58 
59  // let the compiler generate the copy constructors
60  //DualRand(const DualRand & p);
61  //DualRand & operator=(const DualRand & p);
62 
63  double flat();
64  // Returns a pseudo random number between 0 and 1
65  // (excluding the end points)
66 
67  void flatArray(const int size, double * vect);
68  // Fills an array "vect" of specified size with flat random values.
69 
70  void setSeed(long seed, int);
71  // Sets the state of the algorithm according to seed.
72 
73  void setSeeds(const long * seeds, int);
74  // Sets the state of the algorithm according to the zero-terminated
75  // array of seeds.
76 
77  void saveStatus( const char filename[] = "DualRand.conf") const;
78  // Saves on named file the current engine status.
79 
80  void restoreStatus( const char filename[] = "DualRand.conf" );
81  // Reads from named file the last saved engine status and restores it.
82 
83  void showStatus() const;
84  // Dumps the current engine status on the screen.
85 
86  operator double(); // Returns same as flat()
87  operator float(); // flat value, without worrying about filling bits
88  operator unsigned int(); // 32-bit flat value, quickest of all
89 
90  virtual std::ostream & put (std::ostream & os) const;
91  virtual std::istream & get (std::istream & is);
92  static std::string beginTag ( );
93  virtual std::istream & getState ( std::istream & is );
94 
95  std::string name() const;
96  static std::string engineName() {return "DualRand";}
97 
98  std::vector<unsigned long> put () const;
99  bool get (const std::vector<unsigned long> & v);
100  bool getState (const std::vector<unsigned long> & v);
101 
102  static const unsigned int VECTOR_STATE_SIZE = 9;
103 
104 private:
105 
106  // This generator is composed of two others combined:
107 
108  class Tausworthe {
109  public:
110  Tausworthe();
111  Tausworthe(unsigned int seed);
112  operator unsigned int();
113  void put(std::ostream & os) const;
114  void put(std::vector<unsigned long> & v) const;
115  void get(std::istream & is);
116  bool get(std::vector<unsigned long>::const_iterator & iv);
117  private:
118  int wordIndex;
119  unsigned int words[4];
120  }; // Tausworthe
121 
122  class IntegerCong {
123  public:
124  IntegerCong();
125  IntegerCong(unsigned int seed, int streamNumber);
126  operator unsigned int();
127  void put(std::ostream & os) const;
128  void put(std::vector<unsigned long> & v) const;
129  void get(std::istream & is);
130  bool get(std::vector<unsigned long>::const_iterator & iv);
131  private:
132  unsigned int state, multiplier, addend;
133  }; // IntegerCong
134 
135  int numEngines;
136  Tausworthe tausworthe;
137  IntegerCong integerCong;
138 
139 }; // DualRand
140 
141 } // namespace CLHEP
142 
143 #endif // DualRand_h