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//
// G4HelixHeum
//
// Class description:
//
// Simple Heum stepper for magnetic field:
//     x_1 = x_0 +
//           h * 1/4 * dx(t0,x0)  +
//               3/4 * dx(t0+2/3*h, x0+2/3*h*(dx(t0+h/3,x0+h/3*dx(t0,x0)))) 
// Third order solver.

// Author: W.Wander <wwc@mit.edu>, 03/11/1998
// -------------------------------------------------------------------
#ifndef G4HELIXHEUM_HH
#define G4HELIXHEUM_HH

#include "G4MagHelicalStepper.hh"

class G4HelixHeum : public G4MagHelicalStepper
{

  public: // with description

    G4HelixHeum(G4Mag_EqRhs *EqRhs);
    ~G4HelixHeum();
  
    void DumbStepper( const G4double y[],
                            G4ThreeVector Bfld,
                            G4double      h,
                            G4double      yout[] );

  public: // without description
  
    inline G4int IntegratorOrder() const { return 2; }
};

#endif
