RKF45 Class Reference

4/5th Order Runge-Kutta-Fehlberg ODE solver More...

Inheritance diagram for RKF45:

Collaboration diagram for RKF45:

Public Member Functions
	TypeName ("RKF45")
	RKF45 (const ODESystem &ode, const dictionary &dict)
virtual	~RKF45 ()=default
virtual bool	resize ()
virtual scalar	solve (const scalar x0, const scalarField &y0, const scalarField &dydx0, const scalar dx, scalarField &y) const
virtual void	solve (scalar &x, scalarField &y, scalar &dxTry) const
virtual void	solve (scalar &x, scalarField &y, scalar &dxTry) const
virtual void	solve (scalar &x, scalarField &y, stepState &step) const
virtual void	solve (const scalar xStart, const scalar xEnd, scalarField &y, scalar &dxEst) const
Public Member Functions inherited from ODESolver
	TypeName ("ODESolver")
	declareRunTimeSelectionTable (autoPtr, ODESolver, dictionary,(const ODESystem &ode, const dictionary &dict),(ode, dict))
	ODESolver (const ODESystem &ode, const dictionary &dict)
	ODESolver (const ODESystem &ode, const scalarField &absTol, const scalarField &relTol)
virtual	~ODESolver ()=default
label	nEqns () const
scalarField &	absTol ()
scalarField &	relTol ()
template<class Type >
void	resizeField (UList< Type > &f) const
void	resizeMatrix (scalarSquareMatrix &m) const
virtual void	solve (scalar &x, scalarField &y, stepState &step) const
virtual void	solve (const scalar xStart, const scalar xEnd, scalarField &y, scalar &dxEst) const
Public Member Functions inherited from adaptiveSolver
	adaptiveSolver (const ODESystem &ode, const dictionary &dict)
virtual	~adaptiveSolver ()=default
bool	resize (const label n)
void	solve (const ODESystem &ode, scalar &x, scalarField &y, scalar &dxTry) const

Additional Inherited Members
Static Public Member Functions inherited from ODESolver
static autoPtr< ODESolver >	New (const ODESystem &ode, const dictionary &dict)
template<class Type >
static void	resizeField (UList< Type > &f, const label n)
Protected Member Functions inherited from ODESolver
scalar	normalizeError (const scalarField &y0, const scalarField &y, const scalarField &err) const
	ODESolver (const ODESolver &)=delete
void	operator= (const ODESolver &)=delete
Protected Attributes inherited from ODESolver
const ODESystem &	odes_
const label	maxN_
label	n_
scalarField	absTol_
scalarField	relTol_
label	maxSteps_

Detailed Description

4/5th Order Runge-Kutta-Fehlberg ODE solver

References:

    Fehlberg, E. (1969).
    Low-order classical Runge-Kutta formulas with stepsize control
    and their application to some heat transfer problems.
    NASA Technical Report 315.

    Hairer, E., Nørsett, S. P., & Wanner, G. (1993).
    Solving Ordinary Differential Equations I: Nonstiff Problems,
    second edition.
    Springer-Verlag, Berlin.

This method embeds the 4-th order integration step into the 5-th order step and allows to perform an adaptive step-size control using these two order without the need of re-evaluation.

Source files

• RKF45.H
• RKF45.C

Definition at line 68 of file RKF45.H.

Constructor & Destructor Documentation

RKF45()

RKF45	(	const ODESystem &	ode,
		const dictionary &	dict
	)

Definition at line 71 of file RKF45.C.

~RKF45()

virtual ~RKF45 ( )

virtualdefault

Member Function Documentation

TypeName()

TypeName

(

"RKF45"

)

resize()

bool resize ( )

virtual

Implements ODESolver.

Definition at line 87 of file RKF45.C.

References adaptiveSolver::resize(), and ODESolver::resize().

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solve() [1/5]

Foam::scalar solve ( const scalar  x0, const scalarField &  y0, const scalarField &  dydx0, const scalar  dx, scalarField &  y  ) const

virtual

Implements adaptiveSolver.

Definition at line 109 of file RKF45.C.

References Foam::constant::physicoChemical::c2, forAll, y, and Foam::y0().

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solve() [2/5]

void solve ( scalar &  x, scalarField &  y, scalar &  dxTry  ) const

virtual

Reimplemented from ODESolver.

Definition at line 177 of file RKF45.C.

References adaptiveSolver::solve(), x, and y.

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solve() [3/5]

void solve

Definition at line 110 of file ODESolver.C.

solve() [4/5]

void solve

Definition at line 123 of file ODESolver.C.

solve() [5/5]

void solve

Definition at line 136 of file ODESolver.C.

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

• src/ODE/ODESolvers/RKF45/RKF45.H
• src/ODE/ODESolvers/RKF45/RKF45.C