include/Geant4/G4FSALBogackiShampine45.hh

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0025 //
0026 // G4FSALBogackiShampine45
0027 //
0028 // Class description:
0029 //
0030 // Bogacki-Shampine - 8 - 5(4) FSAL stepper
0031
0032 // Created: Somnath Banerjee, Google Summer of Code 2015, 26 May 2015
0033 // Supervision: John Apostolakis, CERN
0034 // --------------------------------------------------------------------
0035 #ifndef G4FSAL_BOGACKI_SHAMPINE_45_HH
0036 #define G4FSAL_BOGACKI_SHAMPINE_45_HH
0037
0038 #include "G4VFSALIntegrationStepper.hh"
0039
0040 class G4FSALBogackiShampine45 : public G4VFSALIntegrationStepper
0041 {
0042   public:
0043
0044     G4FSALBogackiShampine45(G4EquationOfMotion* EqRhs,
0045                             G4int numberOfVariables = 6,
0046                             G4bool primary = true);
0047    ~G4FSALBogackiShampine45() override;
0048
0049     G4FSALBogackiShampine45(const G4FSALBogackiShampine45&) = delete;
0050     G4FSALBogackiShampine45& operator=(const G4FSALBogackiShampine45&) = 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
0059     void interpolate( const G4double yInput[],
0060                       const G4double dydx[],
0061                             G4double yOut[],
0062                             G4double Step,
0063                             G4double tau ) ;
0064
0065     G4double DistChord() const override;
0066     inline G4int IntegratorOrder() const override { return 4; }
0067
0068   private:
0069
0070     void PrepareConstants();
0071
0072     // Working arrays -- used during stepping
0073     //
0074     G4double *ak2, *ak3, *ak4, *ak5, *ak6, *ak7, *ak8, *ak9, *ak10, *ak11,
0075              *DyDx, *yTemp, *yIn;
0076     G4double *pseudoDydx_for_DistChord;
0077
0078     G4double fLastStepLength = -1.0;
0079     G4double *fLastInitialVector, *fLastFinalVector,
0080              *fLastDyDx, *fMidVector, *fMidError;
0081     // for DistChord calculations
0082
0083     G4double b[12];     // Working array for interpolation
0084
0085     G4FSALBogackiShampine45* fAuxStepper = nullptr;
0086
0087     static G4bool fPreparedConstants;
0088     static G4double bi[12][7];
0089 };
0090
0091 #endif