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25 //
26 // G4DormandPrinceRK56
27 //
28 // Class description:
29 //
30 // Dormand-Prince RK 6(5) non-FSAL method
31
32 // Created: Somnath Banerjee, Google Summer of Code 2015, 26 June 2015
33 // Supervision: John Apostolakis, CERN
34 // --------------------------------------------------------------------
35 #ifndef G4DORMAND_PRINCE_RK56_HH
36 #define G4DORMAND_PRINCE_RK56_HH
37
38 #include "G4MagIntegratorStepper.hh"
39
40 class G4DormandPrinceRK56 : public G4MagIntegratorStepper
41 {
42 public:
43
44 G4DormandPrinceRK56( G4EquationOfMotion* EqRhs,
45 G4int numberOfVariables = 6,
46 G4bool primary = true ) ;
47
48 ~G4DormandPrinceRK56() override ;
49
50 G4DormandPrinceRK56(const G4DormandPrinceRK56&) = delete;
51 G4DormandPrinceRK56& operator=(const G4DormandPrinceRK56&) = delete;
52
53 void Stepper( const G4double y[],
54 const G4double dydx[],
55 G4double h,
56 G4double yout[],
57 G4double yerr[] ) override ;
58
59 G4double DistChord() const override;
60 G4int IntegratorOrder() const override { return 5; }
61
62 void SetupInterpolate_low( const G4double yInput[],
63 const G4double dydx[],
64 const G4double Step );
65 // For preparing the Interpolant and calculating the extra stages
66
67 void Interpolate_low( const G4double yInput[],
68 const G4double dydx[],
69 const G4double Step,
70 G4double yOut[],
71 G4double tau );
72 // For calculating the output at the tau fraction of Step
73
74 inline void SetupInterpolation()
75 {
76 SetupInterpolate( fLastInitialVector, fLastDyDx, fLastStepLength);
77 }
78
79 inline void SetupInterpolate( const G4double yInput[],
80 const G4double dydx[],
81 const G4double Step )
82 {
83 SetupInterpolate_low( yInput, dydx, Step);
84 }
85
86 inline void Interpolate( const G4double yInput[],
87 const G4double dydx[],
88 const G4double Step,
89 G4double yOut[],
90 G4double tau )
91 {
92 Interpolate_low( yInput, dydx, Step, yOut, tau);
93 }
94 // For calculating the output at the tau fraction of Step
95
96 inline void Interpolate( G4double tau, G4double yOut[])
97 {
98 Interpolate( fLastInitialVector, fLastDyDx, fLastStepLength, yOut, tau );
99 }
100
101 void SetupInterpolate_high( const G4double yInput[],
102 const G4double dydx[],
103 const G4double Step );
104
105 void Interpolate_high( const G4double yInput[],
106 const G4double dydx[],
107 const G4double Step,
108 G4double yOut[],
109 G4double tau );
110 // For calculating the output at the tau fraction of Step
111
112 private:
113
114 G4double *ak2, *ak3, *ak4, *ak5, *ak6, *ak7, *ak8, *ak9;
115 // For storing intermediate 'k' values in stepper
116 G4double *ak10_low, *ak10, *ak11, * ak12;
117 // For the additional stages of Interpolant
118 G4double *yTemp, *yIn;
119
120 G4double fLastStepLength = -1.0;
121 G4double *fLastInitialVector, *fLastFinalVector,
122 *fLastDyDx, *fMidVector, *fMidError;
123 // For DistChord calculations
124
125 G4DormandPrinceRK56* fAuxStepper = nullptr;
126 };
127
128 #endif /* G4DormandPrinceRK56 */
129