// ******************************************************************** // * License and Disclaimer * // * * // * The Geant4 software is copyright of the Copyright Holders of * // * the Geant4 Collaboration. It is provided under the terms and * // * conditions of the Geant4 Software License, included in the file * // * LICENSE and available at http://cern.ch/geant4/license . These * // * include a list of copyright holders. * // * * // * Neither the authors of this software system, nor their employing * // * institutes,nor the agencies providing financial support for this * // * work make any representation or warranty, express or implied, * // * regarding this software system or assume any liability for its * // * use. Please see the license in the file LICENSE and URL above * // * for the full disclaimer and the limitation of liability. * // * * // * This code implementation is the result of the scientific and * // * technical work of the GEANT4 collaboration. * // * By using, copying, modifying or distributing the software (or * // * any work based on the software) you agree to acknowledge its * // * use in resulting scientific publications, and indicate your * // * acceptance of all terms of the Geant4 Software license. * // ******************************************************************** // // G4BulirschStoer driver // // Class description: // // G4IntegrationDriver is a concrete driver class using // Bulirsch-Stoer method to integrate the equation of motion. // Author: Dmitry Sorokin (CERN, Google Summer of Code 2016), 13.02.2018 // Supervision: John Apostolakis (CERN) // -------------------------------------------------------------------- #ifndef G4BULIRSCH_STOER_DRIVER_HH #define G4BULIRSCH_STOER_DRIVER_HH #include "G4IntegrationDriver.hh" #include "G4BulirschStoer.hh" #include "G4ChordFinderDelegate.hh" /** * @brief G4IntegrationDriver is a concrete driver class * using the Bulirsch-Stoer method to integrate the equation of motion. */ template <> class G4IntegrationDriver: public G4VIntegrationDriver, public G4ChordFinderDelegate> { public: /** * Constructor for the concrete G4IntegrationDriver. * @param[in] hminimum The minumum allowed step.. * @param[in] Boris Pointer to the Bulirsch-Stoer motion algorithm. * @param[in] numberOfComponents The number of integration variables. * @param[in] verbosity Flag for verbosity. */ G4IntegrationDriver( G4double hminimum, G4BulirschStoer* stepper, G4int numberOfComponents = 6, G4int statisticsVerbosity = 1); /** * Default Destructor. */ ~G4IntegrationDriver() = default; /** * Copy constructor and assignment operator not allowed. */ G4IntegrationDriver(const G4IntegrationDriver&) = delete; G4IntegrationDriver& operator=(const G4IntegrationDriver&) = delete; /** * Computes the step to take, based on chord limits. * @param[in,out] track The current track in field. * @param[in] hstep Proposed step length. * @param[in] eps Requested accuracy, y_err/hstep. * @param[in] chordDistance Maximum sagitta distance. * @returns The length of step taken. */ G4double AdvanceChordLimited(G4FieldTrack& track, G4double hstep, G4double eps, G4double chordDistance) override; /** * Dispatch interface method for initialisation/reset of driver. */ void OnStartTracking() override; /** * Dispatch interface method for computing step. Does nothing here. */ void OnComputeStep(const G4FieldTrack* track = nullptr) override; /** * The driver does not implement re-integration. Returns false. */ G4bool DoesReIntegrate() const override; /** * Advances integration accurately by relative accuracy better than 'eps'. * @param[in,out] track The current track in field. * @param[in] stepLen Proposed step length. * @param[in] eps Requested accuracy, y_err/hstep. * @param[in] beginStep Initial minimum integration step. * @returns true if integration succeeds. */ G4bool AccurateAdvance( G4FieldTrack& track, G4double stepLen, G4double eps, G4double beginStep = 0) override; /** * Attempts one integration step, and returns estimated error 'dyerr'. * It does not ensure accuracy. * @param[in,out] y_val The current track in field. * @param[in] dydx dydx array. * @param[in] hstep Proposed step length. * @param[out] missDist Estimated sagitta distance. * @param[out] dyerr Estimated error. * @returns true if integration succeeds. */ G4bool QuickAdvance( G4FieldTrack& y_val, const G4double dydx[], G4double hstep, G4double& missDist, G4double& dyerr) override; /** * Takes one Step that is as large as possible while satisfying the * accuracy criterion. * @param[in,out] y The current track state, y. * @param[in] dydx dydx array. * @param[in,out] curveLength Step start, x. * @param[in] htry Step to attempt. * @param[in] eps The relative accuracy. * @param[out] hdid Step achieved. * @param[out] hnext Proposed next step. */ void OneGoodStep( G4double y[], const G4double dydx[], G4double& curveLength, G4double htry, G4double eps, G4double& hdid, G4double& hnext); /** * Getters for derivatives. */ void GetDerivatives( const G4FieldTrack& track, G4double dydx[]) const override; void GetDerivatives( const G4FieldTrack& track, G4double dydx[], G4double field[]) const override; /** * Setter and getter for verbosity. */ void SetVerboseLevel(G4int level) override; G4int GetVerboseLevel() const override; /** * Computes the new step size . * @param[in] errMaxNorm The normalised error. * @param[in] hstepCurrent The current step size. * @returns The new step size. */ G4double ComputeNewStepSize(G4double errMaxNorm, G4double hstepCurrent) override; /** * Getters and setter for the equation of motion. */ G4EquationOfMotion* GetEquationOfMotion() override; const G4EquationOfMotion* GetEquationOfMotion() const; void SetEquationOfMotion(G4EquationOfMotion* equation) override; /** * Getters for the stepper. */ const G4MagIntegratorStepper* GetStepper() const override; G4MagIntegratorStepper* GetStepper() override; /** * Writes out to stream the parameters/state of the driver. */ void StreamInfo( std::ostream& os ) const override; private: G4int GetNumberOfVarialbles() const; G4double fMinimumStep; G4double fVerbosity; G4ModifiedMidpoint fMidpointMethod; G4BulirschStoer* bulirschStoer; G4double yIn[G4FieldTrack::ncompSVEC], yMid[G4FieldTrack::ncompSVEC], yMid2[G4FieldTrack::ncompSVEC], yOut[G4FieldTrack::ncompSVEC], yOut2[G4FieldTrack::ncompSVEC], yError[G4FieldTrack::ncompSVEC]; G4double dydxCurrent[G4FieldTrack::ncompSVEC]; G4double yCurrent[G4FieldTrack::ncompSVEC]; G4double derivs[2][6][G4FieldTrack::ncompSVEC]; const G4int interval_sequence[2]; using ChordFinderDelegate = G4ChordFinderDelegate>; }; #include "G4BulirschStoerDriver.icc" #endif