| Geant4 Cross Reference |
>> 1 // $Id:$
1 // -*- C++ -*- 2 // -*- C++ -*-
2 // 3 //
3 // ------------------------------------------- 4 // -----------------------------------------------------------------------
4 // HEP Random 5 // HEP Random
5 // --- RandLandau --- 6 // --- RandLandau ---
6 // class header file 7 // class header file
7 // ------------------------------------------- 8 // -----------------------------------------------------------------------
8 // This file is part of Geant4 (simulation too 9 // This file is part of Geant4 (simulation toolkit for HEP).
9 10
10 // Class defining methods for shooting or firi 11 // Class defining methods for shooting or firing Landau distributed
11 // random values. 12 // random values.
12 // 13 //
13 // The Landau distribution is parameterless an 14 // The Landau distribution is parameterless and describes the fluctuations
14 // in energy loss of a particle, making certai 15 // in energy loss of a particle, making certain assumptions. For
15 // definitions and algorithms, the following p 16 // definitions and algorithms, the following papers could be read:
16 // 17 //
17 // Landau, Jour Phys VIII, No. 4, p. 201 (1944 18 // Landau, Jour Phys VIII, No. 4, p. 201 (1944)
18 // Borsh-Supan, Jour Res. of NBS 65B NO. 4 p. 19 // Borsh-Supan, Jour Res. of NBS 65B NO. 4 p. 245 (1961)
19 // Kolbig & Schorr Comp Phys Comm 31 p. 97 (19 20 // Kolbig & Schorr Comp Phys Comm 31 p. 97 (1984)
20 // 21 //
21 // The algorithm implemented comes form RANLAN 22 // The algorithm implemented comes form RANLAN in CERNLIB.
22 23
23 // =========================================== 24 // =======================================================================
24 // M. Fischler - Created: 5th January 2000 25 // M. Fischler - Created: 5th January 2000
25 // M Fischler - put and get to/from strea 26 // M Fischler - put and get to/from streams 12/10/04
26 // 27 //
27 // =========================================== 28 // =======================================================================
28 29
29 #ifndef RandLandau_h 30 #ifndef RandLandau_h
30 #define RandLandau_h 1 31 #define RandLandau_h 1
31 32
32 #include "CLHEP/Random/Random.h" 33 #include "CLHEP/Random/Random.h"
33 #include "CLHEP/Utility/memory.h" 34 #include "CLHEP/Utility/memory.h"
34 35
35 namespace CLHEP { 36 namespace CLHEP {
36 37
37 /** 38 /**
38 * @author 39 * @author
39 * @ingroup random 40 * @ingroup random
40 */ 41 */
41 class RandLandau : public HepRandom { 42 class RandLandau : public HepRandom {
42 43
43 public: 44 public:
44 45
45 inline RandLandau ( HepRandomEngine& anEngin 46 inline RandLandau ( HepRandomEngine& anEngine );
46 inline RandLandau ( HepRandomEngine* anEngin 47 inline RandLandau ( HepRandomEngine* anEngine );
47 48
48 // These constructors should be used to inst 49 // These constructors should be used to instantiate a RandLandau
49 // distribution object defining a local engi 50 // distribution object defining a local engine for it.
50 // The static generator will be skipped usin 51 // The static generator will be skipped using the non-static methods
51 // defined below. 52 // defined below.
52 // If the engine is passed by pointer the co 53 // If the engine is passed by pointer the corresponding engine object
53 // will be deleted by the RandLandau destruc 54 // will be deleted by the RandLandau destructor.
54 // If the engine is passed by reference the 55 // If the engine is passed by reference the corresponding engine object
55 // will not be deleted by the RandLandau des 56 // will not be deleted by the RandLandau destructor.
56 57
57 virtual ~RandLandau(); 58 virtual ~RandLandau();
58 // Destructor 59 // Destructor
59 60
60 // Save and restore to/from streams 61 // Save and restore to/from streams
61 62
62 std::ostream & put ( std::ostream & os ) con 63 std::ostream & put ( std::ostream & os ) const;
63 std::istream & get ( std::istream & is ); 64 std::istream & get ( std::istream & is );
64 65
65 // 66 //
66 // Methods to generate Landau-distributed ra 67 // Methods to generate Landau-distributed random deviates.
67 // 68 //
68 // These deviates are accurate to the actual 69 // These deviates are accurate to the actual Landau distribution to
69 // one part in 10**5 or better. 70 // one part in 10**5 or better.
70 71
71 // Static methods to shoot random values usi 72 // Static methods to shoot random values using the static generator
72 73
73 static inline double shoot(); 74 static inline double shoot();
74 75
75 static void shootArray ( const int size, do 76 static void shootArray ( const int size, double* vect );
76 77
77 // Static methods to shoot random values us 78 // Static methods to shoot random values using a given engine
78 // by-passing the static generator. 79 // by-passing the static generator.
79 80
80 static inline double shoot( HepRandomEngine 81 static inline double shoot( HepRandomEngine* anotherEngine );
81 82
82 static void shootArray ( HepRandomEngine* a 83 static void shootArray ( HepRandomEngine* anotherEngine,
83 const int size, 84 const int size,
84 double* vect ); 85 double* vect );
85 86
86 // Instance methods using the localEngine t 87 // Instance methods using the localEngine to instead of the static
87 // generator, and the default mean and stdD 88 // generator, and the default mean and stdDev established at construction
88 89
89 inline double fire(); 90 inline double fire();
90 91
91 void fireArray ( const int size, double* ve 92 void fireArray ( const int size, double* vect);
92 93
93 inline double operator()(); 94 inline double operator()();
94 95
95 std::string name() const; 96 std::string name() const;
96 HepRandomEngine & engine(); 97 HepRandomEngine & engine();
97 98
98 static std::string distributionName() {retur 99 static std::string distributionName() {return "RandLandau";}
99 // Provides the name of this distribution cl 100 // Provides the name of this distribution class
100 101
101 102
102 protected: 103 protected:
103 104
104 static double transform (double r); 105 static double transform (double r);
105 static double transformSmall (double r); 106 static double transformSmall (double r);
106 107
107 private: 108 private:
108 109
109 std::shared_ptr<HepRandomEngine> localEngine 110 std::shared_ptr<HepRandomEngine> localEngine;
110 111
111 }; 112 };
112 113
113 } // namespace CLHEP 114 } // namespace CLHEP
114 115
115 #include "CLHEP/Random/RandLandau.icc" 116 #include "CLHEP/Random/RandLandau.icc"
116 117
117 #endif 118 #endif
118 119