include/Geant4/G4FSALDormandPrince745.hh

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0025 //
0026 // G4FSALDormandPrince745
0027 //
0028 // Class description:
0029 //
0030 // DormandPrince7 - 5(4) FSAL stepper
0031
0032 // Created: Somnath Banerjee, Google Summer of Code 2015, 25 May 2015
0033 // Supervision: John Apostolakis, CERN
0034 // --------------------------------------------------------------------
0035 #ifndef G4FSALDORMANDPRINCE745_HH
0036 #define G4FSALDORMANDPRINCE745_HH
0037
0038 #include "G4VFSALIntegrationStepper.hh"
0039
0040 class G4FSALDormandPrince745 : public G4VFSALIntegrationStepper
0041 {
0042   public:
0043
0044     G4FSALDormandPrince745(G4EquationOfMotion* EqRhs,
0045                            G4int numberOfVariables = 6,
0046                            G4bool primary = true);
0047    ~G4FSALDormandPrince745() override;
0048
0049     G4FSALDormandPrince745(const G4FSALDormandPrince745&) = delete;
0050     G4FSALDormandPrince745& operator=(const G4FSALDormandPrince745&) = delete;
0051
0052     void Stepper( const G4double y[],
0053                   const G4double dydx[],
0054                         G4double h,
0055                         G4double yout[],
0056                         G4double yerr[],
0057                         G4double nextDydx[]) override ;
0058     void interpolate( const G4double yInput[],
0059                       const G4double dydx[],
0060                             G4double yOut[],
0061                             G4double Step,
0062                             G4double tau ) ;
0063
0064     void SetupInterpolate( const G4double yInput[],
0065                            const G4double dydx[],
0066                            const G4double Step );
0067       // For higher order Interpolant
0068
0069     void Interpolate( const G4double yInput[],
0070                       const G4double dydx[],
0071                       const G4double Step,
0072                             G4double yOut[],
0073                             G4double tau );
0074       // For calculating the output at the tau fraction of Step
0075
0076
0077     G4double  DistChord()   const override;
0078     inline G4int IntegratorOrder() const override { return 4; }
0079     inline G4bool isFSAL() const { return true; }
0080
0081   private:
0082
0083     G4double *ak2, *ak3, *ak4, *ak5, *ak6, *ak7,
0084              *ak8, *ak9,         // For additional stages in the interpolant
0085              *yTemp, *yIn;
0086
0087     G4double* pseudoDydx_for_DistChord;
0088       // Only for use with DistChord()
0089
0090     G4double fLastStepLength = -1.0;
0091     G4double *fLastInitialVector, *fLastFinalVector,
0092              *fInitialDyDx, *fLastDyDx, *fMidVector, *fMidError;
0093       // For DistChord() calculations
0094
0095     G4FSALDormandPrince745* fAuxStepper = nullptr;
0096 };
0097
0098 #endif