| Geant4 Cross Reference |
1 // -*- C++ -*- 1 // -*- C++ -*-
2 // 2 //
3 // ------------------------------------------- 3 // -----------------------------------------------------------------------
4 // HEP Random 4 // HEP Random
5 // --- RandLandau --- 5 // --- RandLandau ---
6 // class header file 6 // class header file
7 // ------------------------------------------- 7 // -----------------------------------------------------------------------
8 // This file is part of Geant4 (simulation too 8 // This file is part of Geant4 (simulation toolkit for HEP).
9 9
10 // Class defining methods for shooting or firi 10 // Class defining methods for shooting or firing Landau distributed
11 // random values. 11 // random values.
12 // 12 //
13 // The Landau distribution is parameterless an 13 // The Landau distribution is parameterless and describes the fluctuations
14 // in energy loss of a particle, making certai 14 // in energy loss of a particle, making certain assumptions. For
15 // definitions and algorithms, the following p 15 // definitions and algorithms, the following papers could be read:
16 // 16 //
17 // Landau, Jour Phys VIII, No. 4, p. 201 (1944 17 // Landau, Jour Phys VIII, No. 4, p. 201 (1944)
18 // Borsh-Supan, Jour Res. of NBS 65B NO. 4 p. 18 // Borsh-Supan, Jour Res. of NBS 65B NO. 4 p. 245 (1961)
19 // Kolbig & Schorr Comp Phys Comm 31 p. 97 (19 19 // Kolbig & Schorr Comp Phys Comm 31 p. 97 (1984)
20 // 20 //
21 // The algorithm implemented comes form RANLAN 21 // The algorithm implemented comes form RANLAN in CERNLIB.
22 22
23 // =========================================== 23 // =======================================================================
24 // M. Fischler - Created: 5th January 2000 24 // M. Fischler - Created: 5th January 2000
25 // M Fischler - put and get to/from strea 25 // M Fischler - put and get to/from streams 12/10/04
26 // 26 //
27 // =========================================== 27 // =======================================================================
28 28
29 #ifndef RandLandau_h 29 #ifndef RandLandau_h
30 #define RandLandau_h 1 30 #define RandLandau_h 1
31 31
32 #include "CLHEP/Random/Random.h" 32 #include "CLHEP/Random/Random.h"
33 #include "CLHEP/Utility/memory.h" 33 #include "CLHEP/Utility/memory.h"
34 34
35 namespace CLHEP { 35 namespace CLHEP {
36 36
37 /** 37 /**
38 * @author 38 * @author
39 * @ingroup random 39 * @ingroup random
40 */ 40 */
41 class RandLandau : public HepRandom { 41 class RandLandau : public HepRandom {
42 42
43 public: 43 public:
44 44
45 inline RandLandau ( HepRandomEngine& anEngin 45 inline RandLandau ( HepRandomEngine& anEngine );
46 inline RandLandau ( HepRandomEngine* anEngin 46 inline RandLandau ( HepRandomEngine* anEngine );
47 47
48 // These constructors should be used to inst 48 // These constructors should be used to instantiate a RandLandau
49 // distribution object defining a local engi 49 // distribution object defining a local engine for it.
50 // The static generator will be skipped usin 50 // The static generator will be skipped using the non-static methods
51 // defined below. 51 // defined below.
52 // If the engine is passed by pointer the co 52 // If the engine is passed by pointer the corresponding engine object
53 // will be deleted by the RandLandau destruc 53 // will be deleted by the RandLandau destructor.
54 // If the engine is passed by reference the 54 // If the engine is passed by reference the corresponding engine object
55 // will not be deleted by the RandLandau des 55 // will not be deleted by the RandLandau destructor.
56 56
57 virtual ~RandLandau(); 57 virtual ~RandLandau();
58 // Destructor 58 // Destructor
59 59
60 // Save and restore to/from streams 60 // Save and restore to/from streams
61 61
62 std::ostream & put ( std::ostream & os ) con 62 std::ostream & put ( std::ostream & os ) const;
63 std::istream & get ( std::istream & is ); 63 std::istream & get ( std::istream & is );
64 64
65 // 65 //
66 // Methods to generate Landau-distributed ra 66 // Methods to generate Landau-distributed random deviates.
67 // 67 //
68 // These deviates are accurate to the actual 68 // These deviates are accurate to the actual Landau distribution to
69 // one part in 10**5 or better. 69 // one part in 10**5 or better.
70 70
71 // Static methods to shoot random values usi 71 // Static methods to shoot random values using the static generator
72 72
73 static inline double shoot(); 73 static inline double shoot();
74 74
75 static void shootArray ( const int size, do 75 static void shootArray ( const int size, double* vect );
76 76
77 // Static methods to shoot random values us 77 // Static methods to shoot random values using a given engine
78 // by-passing the static generator. 78 // by-passing the static generator.
79 79
80 static inline double shoot( HepRandomEngine 80 static inline double shoot( HepRandomEngine* anotherEngine );
81 81
82 static void shootArray ( HepRandomEngine* a 82 static void shootArray ( HepRandomEngine* anotherEngine,
83 const int size, 83 const int size,
84 double* vect ); 84 double* vect );
85 85
86 // Instance methods using the localEngine t 86 // Instance methods using the localEngine to instead of the static
87 // generator, and the default mean and stdD 87 // generator, and the default mean and stdDev established at construction
88 88
89 inline double fire(); 89 inline double fire();
90 90
91 void fireArray ( const int size, double* ve 91 void fireArray ( const int size, double* vect);
92 92
93 inline double operator()(); 93 inline double operator()();
94 94
95 std::string name() const; 95 std::string name() const;
96 HepRandomEngine & engine(); 96 HepRandomEngine & engine();
97 97
98 static std::string distributionName() {retur 98 static std::string distributionName() {return "RandLandau";}
99 // Provides the name of this distribution cl 99 // Provides the name of this distribution class
100 100
101 101
102 protected: 102 protected:
103 103
104 static double transform (double r); 104 static double transform (double r);
105 static double transformSmall (double r); 105 static double transformSmall (double r);
106 106
107 private: 107 private:
108 108
109 std::shared_ptr<HepRandomEngine> localEngine 109 std::shared_ptr<HepRandomEngine> localEngine;
110 110
111 }; 111 };
112 112
113 } // namespace CLHEP 113 } // namespace CLHEP
114 114
115 #include "CLHEP/Random/RandLandau.icc" 115 #include "CLHEP/Random/RandLandau.icc"
116 116
117 #endif 117 #endif
118 118