G4ClassicalRK4 Class Reference

#include <G4ClassicalRK4.hh>

Inheritance diagram for G4ClassicalRK4:

Public Member Functions
	G4ClassicalRK4 (G4EquationOfMotion *EquationMotion, G4int numberOfVariables=6)
	~G4ClassicalRK4 ()
void	DumbStepper (const G4double yIn[], const G4double dydx[], G4double h, G4double yOut[])
G4int	IntegratorOrder () const
Public Member Functions inherited from G4MagErrorStepper
	G4MagErrorStepper (G4EquationOfMotion *EqRhs, G4int numberOfVariables, G4int numStateVariables=12)
virtual	~G4MagErrorStepper ()
void	Stepper (const G4double y[], const G4double dydx[], G4double h, G4double yout[], G4double yerr[])
G4double	DistChord () const
Public Member Functions inherited from G4MagIntegratorStepper
	G4MagIntegratorStepper (G4EquationOfMotion *Equation, G4int numIntegrationVariables, G4int numStateVariables=12)
virtual	~G4MagIntegratorStepper ()
virtual void	ComputeRightHandSide (const G4double y[], G4double dydx[])
void	NormaliseTangentVector (G4double vec[6])
void	NormalisePolarizationVector (G4double vec[12])
void	RightHandSide (const double y[], double dydx[])
G4int	GetNumberOfVariables () const
G4int	GetNumberOfStateVariables () const
G4EquationOfMotion *	GetEquationOfMotion ()
void	SetEquationOfMotion (G4EquationOfMotion *newEquation)

Detailed Description

Definition at line 44 of file G4ClassicalRK4.hh.

Constructor & Destructor Documentation

G4ClassicalRK4::G4ClassicalRK4	(	G4EquationOfMotion *	EquationMotion,
		G4int	numberOfVariables = 6
	)

Definition at line 39 of file G4ClassicalRK4.cc.

References G4INCL::Math::max().

  : G4MagErrorStepper(EqRhs, numberOfVariables)
{
   unsigned int noVariables= std::max(numberOfVariables,8); // For Time .. 7+1
 
   dydxm = new G4double[noVariables];
   dydxt = new G4double[noVariables]; 
   yt    = new G4double[noVariables]; 
}

G4ClassicalRK4::~G4ClassicalRK4

(

)

Definition at line 53 of file G4ClassicalRK4.cc.

{
  delete[] dydxm;
  delete[] dydxt;
  delete[] yt;
}

Member Function Documentation

void G4ClassicalRK4::DumbStepper ( const G4double  yIn[], const G4double  dydx[], G4double  h, G4double  yOut[]  )

virtual

Implements G4MagErrorStepper.

Definition at line 71 of file G4ClassicalRK4.cc.

References G4MagIntegratorStepper::GetNumberOfVariables(), G4MagIntegratorStepper::NormalisePolarizationVector(), and G4MagIntegratorStepper::RightHandSide().

{
  const G4int nvar = this->GetNumberOfVariables();   //  fNumberOfVariables(); 
  G4int i;
  G4double  hh = h*0.5 , h6 = h/6.0  ;

  // Initialise time to t0, needed when it is not updated by the integration.
  //        [ Note: Only for time dependent fields (usually electric) 
  //                  is it neccessary to integrate the time.] 
  yt[7]   = yIn[7]; 
  yOut[7] = yIn[7];

  for(i=0;i<nvar;i++)
  {
    yt[i] = yIn[i] + hh*dydx[i] ;             // 1st Step K1=h*dydx
  }
  RightHandSide(yt,dydxt) ;                   // 2nd Step K2=h*dydxt

  for(i=0;i<nvar;i++)
  { 
    yt[i] = yIn[i] + hh*dydxt[i] ;
  }
  RightHandSide(yt,dydxm) ;                   // 3rd Step K3=h*dydxm

  for(i=0;i<nvar;i++)
  {
    yt[i]   = yIn[i] + h*dydxm[i] ;
    dydxm[i] += dydxt[i] ;                    // now dydxm=(K2+K3)/h
  }
  RightHandSide(yt,dydxt) ;                   // 4th Step K4=h*dydxt
 
  for(i=0;i<nvar;i++)    // Final RK4 output
  {
    yOut[i] = yIn[i]+h6*(dydx[i]+dydxt[i]+2.0*dydxm[i]); //+K1/6+K4/6+(K2+K3)/3
  }
  if ( nvar == 12 )  { NormalisePolarizationVector ( yOut ); }
  
}  // end of DumbStepper ....................................................

G4int G4ClassicalRK4::IntegratorOrder ( ) const

inlinevirtual

Implements G4MagIntegratorStepper.

Definition at line 69 of file G4ClassicalRK4.hh.

{ return 4; }

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The documentation for this class was generated from the following files:

• G4ClassicalRK4.hh
• G4ClassicalRK4.cc