Gabriele Cosmo
104 lines
4.0 KiB
C++
104 lines
4.0 KiB
C++
//
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// ********************************************************************
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// * License and Disclaimer *
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// * *
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// * The Geant4 software is copyright of the Copyright Holders of *
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// * the Geant4 Collaboration. It is provided under the terms and *
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// * conditions of the Geant4 Software License, included in the file *
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// * LICENSE and available at http://cern.ch/geant4/license . These *
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// * include a list of copyright holders. *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. Please see the license in the file LICENSE and URL above *
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// * for the full disclaimer and the limitation of liability. *
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// * *
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// * This code implementation is the result of the scientific and *
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// * technical work of the GEANT4 collaboration. *
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// * By using, copying, modifying or distributing the software (or *
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// * any work based on the software) you agree to acknowledge its *
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// * use in resulting scientific publications, and indicate your *
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// * acceptance of all terms of the Geant4 Software license. *
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// ********************************************************************
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//
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// G4ClassicalRK4
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//
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// Class description:
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//
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// Integrate the equations of the motion of a particle in a magnetic field
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// using the classical 4th Runge-Kutta method.
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// Authors: J.Apostolakis, V.Grichine (CERN), 30.01.1997
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// -------------------------------------------------------------------
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#ifndef G4CLASSICALRK4_HH
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#define G4CLASSICALRK4_HH
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#include "G4MagErrorStepper.hh"
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/**
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* @brief G4ClassicalRK4 integrates the equations of the motion of a particle
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* in a magnetic field using the classical 4th Runge-Kutta method.
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*/
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class G4ClassicalRK4 : public G4MagErrorStepper
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{
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public:
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/**
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* Constructor for G4ClassicalRK4.
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* @param[in] EquationMotion Pointer to the provided equation of motion.
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* @param[in] numberOfVariables The number of integration variables.
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*/
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G4ClassicalRK4(G4EquationOfMotion* EquationMotion,
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G4int numberOfVariables = 6) ;
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/**
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* Destructor.
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*/
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~G4ClassicalRK4() override ;
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/**
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* Copy constructor and assignment operator not allowed.
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*/
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G4ClassicalRK4(const G4ClassicalRK4&) = delete;
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G4ClassicalRK4& operator=(const G4ClassicalRK4&) = delete;
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// A stepper that does not know about errors.
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// It is used by the MagErrorStepper stepper.
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/**
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* Given values for the variables y[0,..,n-1] and their derivatives
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* dydx[0,...,n-1] known at x, uses the classical 4th Runge-Kutta
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* method to advance the solution over an interval h and returns the
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* incremented variables as yout[0,...,n-1]. The user supplies the
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* function RightHandSide(x,y,dydx), which returns derivatives dydx at x.
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* The source is routine rk4 from NRC p.712-713.
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* @param[in] yIn Starting values array of integration variables.
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* @param[in] dydx Derivatives array.
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* @param[in] h The given step size.
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* @param[out] yOut Integration output.
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*/
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void DumbStepper( const G4double yIn[],
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const G4double dydx[],
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G4double h,
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G4double yOut[] ) override ;
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/**
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* Returns the order, 4, of integration.
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*/
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G4int IntegratorOrder() const override { return 4; }
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/**
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* Returns the stepper type-ID, "kClassicalRK4".
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*/
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G4StepperType StepperType() const override { return kClassicalRK4; }
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private:
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G4double *dydxm, *dydxt, *yt; // scratch space - not state
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};
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#endif
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