include/Geant4/G4BulirschStoerDriver.hh

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0024 //
0025 // G4BulirschStoer driver
0026 //
0027 // Class description:
0028 //
0029 // G4IntegrationDriver<G4BulirschStoer> is a driver class using
0030 // Bulirsch-Stoer method to integrate the equation of motion.
0031
0032 // Author: Dmitry Sorokin, Google Summer of Code 2016
0033 // Supervision: John Apostolakis, CERN
0034 // --------------------------------------------------------------------
0035 #ifndef G4BULIRSCH_STOER_DRIVER_HH
0036 #define G4BULIRSCH_STOER_DRIVER_HH
0037
0038 #include "G4IntegrationDriver.hh"
0039 #include "G4BulirschStoer.hh"
0040 #include "G4ChordFinderDelegate.hh"
0041
0042 template <>
0043 class G4IntegrationDriver<G4BulirschStoer>:
0044     public G4VIntegrationDriver,
0045     public G4ChordFinderDelegate<G4IntegrationDriver<G4BulirschStoer>>
0046 {
0047   public:
0048
0049     G4IntegrationDriver( G4double hminimum,
0050                          G4BulirschStoer* stepper,
0051                          G4int numberOfComponents = 6,
0052                          G4int statisticsVerbosity = 1);
0053
0054     ~G4IntegrationDriver() = default;
0055
0056     G4IntegrationDriver(const G4IntegrationDriver&) = delete;
0057     G4IntegrationDriver& operator=(const G4IntegrationDriver&) = delete;
0058
0059     virtual G4double AdvanceChordLimited(G4FieldTrack& track,
0060                                          G4double hstep,
0061                                          G4double eps,
0062                                          G4double chordDistance) override
0063     {
0064       return ChordFinderDelegate::
0065              AdvanceChordLimitedImpl(track, hstep, eps, chordDistance);
0066     }
0067
0068     virtual void OnStartTracking() override
0069     {
0070       ChordFinderDelegate::ResetStepEstimate();
0071     }
0072
0073     virtual void OnComputeStep(const G4FieldTrack* /*track*/ = nullptr) override {};
0074
0075     virtual G4bool DoesReIntegrate() const override { return false; }  /// ????
0076
0077     virtual G4bool AccurateAdvance( G4FieldTrack& track,
0078                                     G4double stepLen,
0079                                     G4double eps,
0080                                     G4double beginStep = 0) override;
0081
0082     virtual G4bool QuickAdvance( G4FieldTrack& y_val,
0083                                  const G4double dydx[],
0084                                  G4double hstep,
0085                                  G4double& missDist,
0086                                  G4double& dyerr) override;
0087
0088     void OneGoodStep( G4double y[],
0089                       const G4double dydx[],
0090                       G4double& curveLength,
0091                       G4double htry,
0092                       G4double eps,
0093                       G4double& hdid,
0094                       G4double& hnext);
0095
0096     virtual void GetDerivatives( const G4FieldTrack& track,
0097                                  G4double dydx[]) const override;
0098
0099     virtual void GetDerivatives( const G4FieldTrack& track,
0100                                  G4double dydx[],
0101                                  G4double field[]) const override;
0102
0103     virtual void SetVerboseLevel(G4int level) override;
0104     virtual G4int GetVerboseLevel() const override;
0105
0106     virtual G4double ComputeNewStepSize(
0107                           G4double  errMaxNorm,    // normalised error
0108                           G4double  hstepCurrent) override; // current step size
0109
0110     virtual G4EquationOfMotion* GetEquationOfMotion() override;
0111     const G4EquationOfMotion* GetEquationOfMotion() const;
0112     virtual void SetEquationOfMotion(G4EquationOfMotion* equation) override;
0113
0114     virtual const G4MagIntegratorStepper* GetStepper() const override;
0115     virtual G4MagIntegratorStepper* GetStepper() override;
0116
0117     virtual void  StreamInfo( std::ostream& os ) const override;
0118      // Write out the parameters / state of the driver
0119
0120   private:
0121
0122     G4int GetNumberOfVarialbles() const;
0123
0124     G4double fMinimumStep;
0125     G4double fVerbosity;
0126
0127     G4ModifiedMidpoint fMidpointMethod;
0128     G4BulirschStoer* bulirschStoer;
0129
0130     G4double yIn[G4FieldTrack::ncompSVEC],
0131              yMid[G4FieldTrack::ncompSVEC],
0132              yMid2[G4FieldTrack::ncompSVEC],
0133              yOut[G4FieldTrack::ncompSVEC],
0134              yOut2[G4FieldTrack::ncompSVEC],
0135              yError[G4FieldTrack::ncompSVEC];
0136
0137
0138     G4double dydxCurrent[G4FieldTrack::ncompSVEC];
0139     G4double yCurrent[G4FieldTrack::ncompSVEC];
0140
0141     G4double derivs[2][6][G4FieldTrack::ncompSVEC];
0142
0143     const G4int interval_sequence[2];
0144
0145     using ChordFinderDelegate =
0146           G4ChordFinderDelegate<G4IntegrationDriver<G4BulirschStoer>>;
0147 };
0148
0149 #include "G4BulirschStoerDriver.icc"
0150
0151 #endif