| Geant4 Cross Reference |
1 //
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25 //
26 // G4VelocityTable
27 //
28 // Class description:
29 //
30 // This class keeps a table of velocity as a function of the ratio
31 // kinetic erngy and mass. G4VelocityTable is used by
32 // G4Track::CalculateVelocity().
33
34 // Author: Hisaya Kurashige, 17 August 2011
35 // --------------------------------------------------------------------
36 #ifndef G4VelocityTable_hh
37 #define G4VelocityTable_hh 1
38
39 #include <vector>
40 #include <iostream>
41
42 #include "globals.hh"
43 #include "G4ios.hh"
44 #include "G4ThreadLocalSingleton.hh"
45
46 class G4VelocityTable
47 {
48 friend class G4ThreadLocalSingleton<G4VelocityTable>;
49
50 using G4VTDataVector = std::vector<G4double>;
51
52 public:
53
54 G4double Value(G4double theEnergy);
55 // Get the cross-section/energy-loss value corresponding to the
56 // given energy. An appropriate interpolation is used to calculate
57 // the value
58
59 static G4VelocityTable* GetVelocityTable();
60
61 static void SetVelocityTableProperties(G4double t_max, G4double t_min,
62 G4int nbin);
63 static G4double GetMaxTOfVelocityTable();
64 static G4double GetMinTOfVelocityTable();
65 static G4int GetNbinOfVelocityTable();
66
67 private:
68
69 G4VelocityTable();
70 ~G4VelocityTable();
71
72 void PrepareVelocityTable();
73
74 std::size_t FindBinLocation(G4double theEnergy) const;
75 // Find the bin# in which theEnergy belongs - pure virtual function
76
77 inline G4double Interpolation() const;
78
79 // --------------------------------------------------------------------
80
81 G4double edgeMin = 0.0; // Energy of first point
82 G4double edgeMax = 0.0; // Energy of the last point
83
84 std::size_t numberOfNodes = 0;
85
86 G4VTDataVector dataVector; // Vector to keep the crossection/energyloss
87 G4VTDataVector binVector; // Vector to keep energy
88 G4VTDataVector secDerivative; // Vector to keep second derivatives
89
90 G4double dBin = 0.0; // Bin width - useful only for fixed binning
91 G4double baseBin = 0.0; // Set this in constructor for performance
92
93 G4double lastEnergy = -DBL_MAX; // Cache the last input value
94 G4double lastValue = 0.0; // Cache the last output value
95 std::size_t lastBin = 0; // Cache the last bin location
96
97 static G4ThreadLocal G4VelocityTable* theInstance;
98
99 G4double maxT = 1000.0;
100 G4double minT = 0.0001;
101 G4int NbinT = 500;
102 };
103
104 // ----------------------
105 // Inline methods
106 // ----------------------
107
108 inline G4double G4VelocityTable::Interpolation() const
109 {
110 // Linear interpolation is used to get the value. If the give energy
111 // is in the highest bin, no interpolation will be Done. Because
112 // there is an extra bin hidden from a user at locBin=numberOfBin,
113 // the following interpolation is valid even the current locBin=
114 // numberOfBin-1.
115
116 G4double intplFactor =
117 (lastEnergy - binVector[lastBin]) /
118 (binVector[lastBin + 1] - binVector[lastBin]); // Interpol. factor
119
120 return dataVector[lastBin] +
121 (dataVector[lastBin + 1] - dataVector[lastBin]) * intplFactor;
122 }
123
124 #endif
125