//
// ********************************************************************
// * 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.          *
// ********************************************************************
//
//
// $Id: G4HelixExplicitEuler.hh,v 1.9 2007-08-21 08:52:00 tnikitin Exp $
// GEANT4 tag $Name: not supported by cvs2svn $
//
//
// class G4HelixExplicitEuler
//
// Class description:
//
// Helix Explicit Euler: x_1 = x_0 + helix(h)
// with helix(h) being a helix piece of length h.
// A simple approach for solving linear differential equations.
// Take the current derivative and add it to the current position.

// History:
// - Created. W.Wander <wwc@mit.edu>, 12/09/97
// -------------------------------------------------------------------

#ifndef G4HELIXEXPLICITEULER_HH
#define G4HELIXEXPLICITEULER_HH

#include "G4MagHelicalStepper.hh"

class G4HelixExplicitEuler : public G4MagHelicalStepper
{
  public:  // with description

    G4HelixExplicitEuler(G4Mag_EqRhs *EqRhs)
      : G4MagHelicalStepper(EqRhs) {}
 
    ~G4HelixExplicitEuler() {}
   void Stepper( const G4double y[],
                  const G4double*,
                        G4double h,
                        G4double yout[],
                        G4double yerr[]  ); 

   void DumbStepper( const G4double y[],
                           G4ThreeVector  Bfld,
                           G4double       h,
                           G4double       yout[]);
   
  G4double DistChord() const;
  public:  // without description

    // DELETED  RightHandSide( ) !!!!  
    // Replaced by MagFieldEvaluate( const G4double y[], G4double B[] )   
    // in G4HelicalStepper
  
    G4int IntegratorOrder() const { return 1; }
};

#endif /* G4EXPLICITEULER_HH */