Files
geant4/source/geometry/magneticfield/include/G4BogackiShampine23.hh
T

93 lines
3.8 KiB
C++

//
// ********************************************************************
// * 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. *
// ********************************************************************
//
// G4BogackiShampine23
//
// Class description:
//
// Bogacki-Shampine - 4 - 3(2) non-FSAL implementation
//
// An implementation of the embedded RK method from the paper
// [1] P. Bogacki and L. F. Shampine,
// "A 3(2) pair of Runge - Kutta formulas"
// Appl. Math. Lett., vol. 2, no. 4, pp. 321-325, Jan. 1989.
//
// This version does not utilise the FSAL property of the method,
// which would allow the reuse of the last derivative in the next step.
// (Alternative FSAL implementation created with revised interface)
// Created: Somnath Banerjee, Google Summer of Code 2015, 20 May 2015
// Supervision: John Apostolakis, CERN
// --------------------------------------------------------------------
#ifndef G4BOGACKI_SHAMPINE23_HH
#define G4BOGACKI_SHAMPINE23_HH
#include "G4MagIntegratorStepper.hh"
#include "G4FieldTrack.hh"
class G4BogackiShampine23 : public G4MagIntegratorStepper
{
public:
G4BogackiShampine23(G4EquationOfMotion* EqRhs,
G4int numberOfVariables = 6);
virtual void Stepper(const G4double yInput[],
const G4double dydx[],
G4double hstep,
G4double yOutput[],
G4double yError[]) override;
void Stepper(const G4double yInput[],
const G4double dydx[],
G4double hstep,
G4double yOutput[],
G4double yError[],
G4double dydxOutput[]);
G4BogackiShampine23(const G4BogackiShampine23&) = delete;
G4BogackiShampine23& operator = (const G4BogackiShampine23&) = delete;
virtual G4double DistChord() const override;
virtual G4int IntegratorOrder() const override { return 3; }
private:
void makeStep(const G4double yInput[],
const G4double dydx[],
const G4double hstep,
G4double yOutput[],
G4double* dydxOutput = nullptr,
G4double* yError = nullptr) const;
G4double fyIn[G4FieldTrack::ncompSVEC],
fdydx[G4FieldTrack::ncompSVEC],
fyOut[G4FieldTrack::ncompSVEC],
fdydxOut[G4FieldTrack::ncompSVEC];
G4double fhstep = -1.0;
};
#endif