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//
//  Bogacki-Shampine - 8 - 5(4) FSAL implementation by Somnath Banerjee
//  Supervision / code review: John Apostolakis
//
// Sponsored by Google in Google Summer of Code 2015.
// 
// First version: 26 May 2015
//
//  History
// -----------------------------
//  Created by Somnath on 26 May 2015
//
//
///////////////////////////////////////////////////////////////////////////////

#ifndef G4FSAL_Bogacki_Shampine_45_hh
#define G4FSAL_Bogacki_Shampine_45_hh

#include "G4VFSALIntegrationStepper.hh"

class G4FSALBogackiShampine45 : public G4VFSALIntegrationStepper
{
public:
    G4FSALBogackiShampine45(G4EquationOfMotion *EqRhs,
                     G4int numberOfVariables = 6,
                     G4bool primary =  true);
    ~G4FSALBogackiShampine45();
    
    void Stepper( const G4double y[],
                  const G4double dydx[],
              	   		G4double h,
                	 	G4double yout[],
                 		G4double yerr[],
                 		G4double nextDydx[]) ;
    
    void interpolate( const G4double yInput[],
                      const G4double dydx[],
                            G4double yOut[],
                            G4double Step,
                            G4double tau ) ;
    
    
    G4double  DistChord()   const;
    G4int IntegratorOrder() const { return 4; }
    
    private :
    
    G4FSALBogackiShampine45(const G4FSALBogackiShampine45&);
    G4FSALBogackiShampine45& operator=(const G4FSALBogackiShampine45&);
    
    G4double *ak2, *ak3, *ak4, *ak5, *ak6, *ak7, *ak8,
    *ak9, *ak10, *ak11,
    *yTemp, *yIn;
    
    G4double *pseudoDydx_for_DistChord;
    G4double fLastStepLength;
    G4double *fLastInitialVector, *fLastFinalVector,
    *fLastDyDx, *fMidVector, *fMidError;
    // for DistChord calculations
    
    G4FSALBogackiShampine45* fAuxStepper;
};

#endif /* defined( G4FSAL_Bogacki_Shampine_45_hh ) */