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Random.h
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1 // -*- C++ -*-
2 //
3 // -----------------------------------------------------------------------
4 // HEP Random
5 // --- HepRandom ---
6 // class header file
7 // -----------------------------------------------------------------------
8 // This file is part of Geant4 (simulation toolkit for HEP).
9 //
10 // It's a singleton instantiated by default within the HEP Random module.
11 // It uses an instantiated HepJamesRandom engine as default algorithm
12 // for pseudo-random number generation. HepRandom defines a static private
13 // data member theGenerator and a set of static inlined methods to manipulate
14 // it. By means of theGenerator the user can change the underlying engine
15 // algorithm, get and set the seeds and use any kind of defined random
16 // distribution.
17 // Distribution classes inherit from HepRandom and define both static and
18 // not-static interfaces.
19 // A static table of uncorrelated seeds is available in this class.
20 // A static method "getTheTableSeeds()" is defined to access a couple of
21 // seeds at a given index in the table.
22 
23 // =======================================================================
24 // Gabriele Cosmo - Created: 5th Sep 1995
25 // - Minor update: 17th May 1996
26 // - Poisson now operates on doubles : 31st Oct 1996
27 // - Added methods for engine status: 19th Nov 1996
28 // - Fixed default values to setTheSeed() and
29 // setTheSeeds() static methods: 16th Oct 1997
30 // - Modified HepRandom to act as a singleton, constructors
31 // are kept public for backward compatibility. Added table
32 // of seeds from HepRandomEngine: 19th Mar 1998
33 // - Relocated Poisson and Gauss data and simplified
34 // initialisation of static generator: 5th Jan 1999
35 // =======================================================================
36 
37 #ifndef HepRandom_h
38 #define HepRandom_h 1
39 
40 #include "CLHEP/Random/RandomEngine.h"
41 
42 namespace CLHEP {
43 
48 class HepRandom {
49 
50 public:
51 
52  HepRandom();
53  HepRandom(long seed);
54  // Contructors with and without a seed using the default engine
55  // (MixMax).
56 
57  HepRandom(HepRandomEngine & algorithm);
58  HepRandom(HepRandomEngine * algorithm);
59  // Constructor taking an alternative engine as argument. If a pointer is
60  // given the corresponding object will be deleted by the HepRandom
61  // destructor.
62 
63  virtual ~HepRandom();
64  // Destructor
65 
66  // implicitly allow compiler-generated copy functions
67 
68  double flat();
69  // Returns the flat value ( interval ]0...1[ ).
70 
71  void flatArray(const int size, double* vect);
72  // Fills "vect" array of flat random values, given the size.
73 
74  inline double flat (HepRandomEngine* theNewEngine);
75  // Returns a flat value, given a defined Random Engine.
76 
77  inline void flatArray(HepRandomEngine* theNewEngine,
78  const int size, double* vect);
79  // Fills "vect" array of flat random values, given the size
80  // and a defined Random Engine.
81 
82  virtual double operator()();
83  // To get a flat random number using the operator ().
84 
85  virtual std::string name() const;
86  virtual HepRandomEngine & engine();
87 
88 
89  virtual std::ostream & put ( std::ostream & os ) const;
90  virtual std::istream & get ( std::istream & is );
91  // Save and restore to/from streams
92 
93  // --------------------------------------------------
94  // Static member functions using the static generator
95  // --------------------------------------------------
96 
97  static void setTheSeed(long seed, int lux=3);
98  // (Re)Initializes the generator with a seed.
99 
100  static long getTheSeed();
101  // Gets the current seed of the current generator.
102 
103  static void setTheSeeds(const long* seeds, int aux=-1);
104  // (Re)Initializes the generator with a zero terminated list of seeds.
105 
106  static const long* getTheSeeds();
107  // Gets the current array of seeds of the current generator.
108 
109  static void getTheTableSeeds (long* seeds, int index);
110  // Gets the array of seeds in the static seedTable at "index" position.
111 
112  static HepRandom * getTheGenerator();
113  // Return the current static generator.
114 
115  static void setTheEngine (HepRandomEngine* theNewEngine);
116  // To set the underlying algorithm object.
117 
118  static HepRandomEngine * getTheEngine();
119  // Returns a pointer to the underlying algorithm object.
120 
121  static void saveEngineStatus( const char filename[] = "Config.conf" );
122  // Saves to file the current status of the current engine.
123 
124  static void restoreEngineStatus( const char filename[] = "Config.conf" );
125  // Restores a saved status (if any) for the current engine.
126 
127  static std::ostream& saveFullState ( std::ostream & os );
128  // Saves to stream the state of the engine and cached data.
129 
130  static std::istream& restoreFullState ( std::istream & is );
131  // Restores from stream the state of the engine and cached data.
132 
133  static std::ostream& saveDistState ( std::ostream & os ) {return os;}
134  // Saves to stream the state of the cached data.
135 
136  static std::istream& restoreDistState ( std::istream & is ) {return is;}
137  // Restores from stream the state of the cached data.
138 
139  static std::ostream& saveStaticRandomStates ( std::ostream & os );
140  // Saves to stream the engine and cached data for all distributions.
141 
142  static std::istream& restoreStaticRandomStates ( std::istream & is );
143  // Restores from stream the engine and cached data for all distributions.
144 
145  static void showEngineStatus();
146  // Dumps the current engine status on screen.
147 
148  static int createInstance();
149  // used to initialise the default engine
150 
151  static std::string distributionName() {return "HepRandomEngine";}
152  // Provides the name of this distribution class
153 
154 protected: // -------- Data members ---------
155 
156  static const long seedTable[215][2];
157  // Table of seeds
158 
159 };
160 
161 std::ostream & operator<< (std::ostream & os, const HepRandom & dist);
162 std::istream & operator>> (std::istream & is, HepRandom & dist);
163 
164 } // namespace CLHEP
165 
166 #include "CLHEP/Random/Random.icc"
167 
168 #endif