G4ImplicitEuler.hh

Go to the documentation of this file.

//
// ********************************************************************
// * 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.          *
// ********************************************************************
//
// G4ImplicitEuler
//
// Class description:
//
// Implicit Euler stepper for magnetic field:
//      x_1 = x_0 + h/2 * ( dx(t_0,x_0) + dx(t_0+h,x_0+h*dx(t_0,x_0) ) )
//
// Second order solver.
// Takes the current derivative and add it to the current position.
// Takes the output and its derivative. Adds the mean of both
// derivatives to form the final output.
 
// Author: W. Wander <[email protected]>, 12.09.1997
// -------------------------------------------------------------------
#ifndef G4IMPLICITEULER_HH
#define G4IMPLICITEULER_HH
 
#include "G4MagErrorStepper.hh"
 
class G4ImplicitEuler : public G4MagErrorStepper
{
  public:
 
    G4ImplicitEuler(G4EquationOfMotion* EqRhs, G4int numberOfVariables = 6);
   ~G4ImplicitEuler() override;
 
    void  DumbStepper( const G4double y[] ,
                       const G4double dydx[] ,
                             G4double h ,
                             G4double yout[] ) override;
 
    inline G4int IntegratorOrder() const override { return 2; }
 
  private:
 
    G4double* dydxTemp = nullptr;
    G4double* yTemp = nullptr;    
      // Temporaries, created to avoid new/delete on every call
};
 
#endif