BDSIntegratorMultipoleThin.hh

/* 
Beam Delivery Simulation (BDSIM) Copyright (C) BDSIM Collaboration, 2001 - 2026.
 
This file is part of BDSIM.
 
BDSIM is free software: you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published 
by the Free Software Foundation version 3 of the License.
 
BDSIM is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with BDSIM.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef BDSINTEGRATORMULTIPOLETHIN_H
#define BDSINTEGRATORMULTIPOLETHIN_H
 
#include "BDSIntegratorMag.hh"
 
#include "globals.hh"
#include <list>
#include <vector>
 
class G4Mag_EqRhs;
class BDSMagnetStrength;
 
class BDSIntegratorMultipoleThin: public BDSIntegratorMag
{
public:
  BDSIntegratorMultipoleThin(BDSMagnetStrength const* strength,
                             G4double                 brhoIn,
                             G4Mag_EqRhs*             eqOfMIn);
  
  virtual ~BDSIntegratorMultipoleThin(){;}
 
  virtual void Stepper(const G4double yIn[],
                       const G4double dydx[],
                       const G4double h,
                       G4double       yOut[],
                       G4double       yErr[]);
 
  void OneStep(const G4ThreeVector& posIn,
               const G4ThreeVector& momUIn, // assumed unit momentum of momIn
               const G4double       momIn,
               G4ThreeVector&       posOut,
               G4ThreeVector&       momOut,
               G4double             h) const;
 
private:
  BDSIntegratorMultipoleThin() = delete;
 
  G4int Factorial(G4int n);
 
  G4double brho;
 
  G4double b0l;
  std::list<double>  bnl;
  std::list<double>  bsl;
  std::vector<G4int> nfact;
};
 
#endif