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RandBreitWigner.h
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1 // -*- C++ -*-
2 //
3 // -----------------------------------------------------------------------
4 // HEP Random
5 // --- RandBreitWigner ---
6 // class header file
7 // -----------------------------------------------------------------------
8 // This file is part of Geant4 (simulation toolkit for HEP).
9 //
10 // Class defining methods for shooting numbers according to the
11 // Breit-Wigner distribution algorithms (plain or mean^2).
12 // Default values are set: mean=1, gamma=.2, cut=1.
13 // Plain algorithm is used for shootArray() and fireArray().
14 // Plain algorithm with default values is used for operator()().
15 
16 // =======================================================================
17 // Gabriele Cosmo - Created: 5th September 1995
18 // - Added methods to shoot arrays: 28th July 1997
19 // J.Marraffino - Added default arguments as attributes and
20 // operator() with arguments: 16th Feb 1998
21 // M Fischler - put and get to/from streams 12/10/04
22 // =======================================================================
23 
24 #ifndef RandBreitWigner_h
25 #define RandBreitWigner_h 1
26 
27 #include "CLHEP/Random/RandFlat.h"
28 #include "CLHEP/Utility/memory.h"
29 
30 namespace CLHEP {
31 
36 class RandBreitWigner : public HepRandom {
37 
38 public:
39 
40  inline RandBreitWigner ( HepRandomEngine& anEngine, double a=1.0,
41  double b=0.2 );
42  inline RandBreitWigner ( HepRandomEngine* anEngine, double a=1.0,
43  double b=0.2 );
44  // These constructors should be used to instantiate a RandBreitWigner
45  // distribution object defining a local engine for it.
46  // The static generator will be skipped using the non-static methods
47  // defined below.
48  // If the engine is passed by pointer the corresponding engine object
49  // will be deleted by the RandBreitWigner destructor.
50  // If the engine is passed by reference the corresponding engine object
51  // will not be deleted by the RandBreitWigner destructor.
52 
53  virtual ~RandBreitWigner();
54  // Destructor
55 
56  // Static methods to shoot random values using the static generator
57 
58  static double shoot( double a=1.0, double b=0.2 );
59 
60  static double shoot( double a, double b, double c );
61 
62  static double shootM2( double a=1.0, double b=0.2 );
63 
64  static double shootM2( double a, double b, double c );
65 
66  static void shootArray ( const int size, double* vect);
67 
68  static void shootArray ( const int size, double* vect,
69  double a, double b );
70 
71  static void shootArray ( const int size, double* vect,
72  double a, double b, double c );
73 
74  // Static methods to shoot random values using a given engine
75  // by-passing the static generator.
76 
77  static double shoot( HepRandomEngine* anEngine, double a=1.0,
78  double b=0.2 );
79  static double shoot( HepRandomEngine* anEngine, double a,
80  double b, double c );
81  static double shootM2( HepRandomEngine* anEngine, double a=1.0,
82  double b=0.2 );
83  static double shootM2( HepRandomEngine* anEngine, double a,
84  double b, double c );
85  static void shootArray ( HepRandomEngine* anEngine,
86  const int size, double* vect );
87  static void shootArray ( HepRandomEngine* anEngine,
88  const int size, double* vect,
89  double a, double b );
90  static void shootArray ( HepRandomEngine* anEngine,
91  const int size, double* vect,
92  double a, double b, double c );
93 
94  // Methods using the localEngine to shoot random values, by-passing
95  // the static generator. These methods respect distribution parameters
96  // passed by the user at instantiation unless superseded by actual
97  // arguments in the call.
98 
99  double fire();
100 
101  double fire( double a, double b );
102 
103  double fire( double a, double b, double c );
104 
105  double fireM2();
106 
107  double fireM2( double a, double b );
108 
109  double fireM2( double a, double b, double c );
110 
111  void fireArray ( const int size, double* vect);
112 
113  void fireArray ( const int size, double* vect,
114  double a, double b );
115 
116  void fireArray ( const int size, double* vect,
117  double a, double b, double c );
118  double operator()();
119  double operator()( double a, double b );
120  double operator()( double a, double b, double c );
121 
122  // Save and restore to/from streams
123 
124  std::ostream & put ( std::ostream & os ) const;
125  std::istream & get ( std::istream & is );
126 
127  std::string name() const;
128  HepRandomEngine & engine();
129 
130  static std::string distributionName() {return "RandBreitWigner";}
131  // Provides the name of this distribution class
132 
133 private:
134 
135  std::shared_ptr<HepRandomEngine> localEngine;
136  double defaultA;
137  double defaultB;
138 
139 };
140 
141 } // namespace CLHEP
142 
143 #include "CLHEP/Random/RandBreitWigner.icc"
144 
145 #endif