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//
// G4VFSALIntegrationStepper inline methods implementation
//
// Author: Somnath Banerjee (CERN, Google Summer of Code 2015), 26.05.2016
// Supervision: John Apostolakis (CERN)
// --------------------------------------------------------------------

inline
G4EquationOfMotion* G4VFSALIntegrationStepper::GetEquationOfMotion()
{
  return fEquation_Rhs;
} 

inline void
 G4VFSALIntegrationStepper::SetEquationOfMotion(G4EquationOfMotion* newEquation)
{
  if( newEquation != nullptr )
  {
    fEquation_Rhs = newEquation;
  }
} 

inline
G4int G4VFSALIntegrationStepper::GetNumberOfVariables() const
{
  return fNoIntegrationVariables;
}

inline
G4int G4VFSALIntegrationStepper::GetNumberOfStateVariables() const
{
  return fNoStateVariables;
}

inline
void G4VFSALIntegrationStepper::NormaliseTangentVector( G4double vec[6] )
{
  G4double drds2 = vec[3]*vec[3]+vec[4]*vec[4]+vec[5]*vec[5];

  if( std::fabs(drds2 - 1.0) > 1.e-14 )
  {
    G4double normx = 1.0 / std::sqrt(drds2);
    for(auto i=3; i<6; ++i) { vec[i] *= normx; }
  }
}

inline
void G4VFSALIntegrationStepper::NormalisePolarizationVector( G4double vec[12] )
{
  G4double drds2 = vec[9]*vec[9]+vec[10]*vec[10]+vec[11]*vec[11];

  if( drds2 > 0. )
  {
    if( std::fabs(drds2 - 1.0) > 1.e-14 )
    {
      G4double normx = 1.0 / std::sqrt(drds2);
      for(auto i=9; i<12; ++i)  { vec[i] *= normx; }
    }
  }
}