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

Inheritance diagram for RKF45:

Collaboration diagram for RKF45:

Public Member Functions
	TypeName ("RKF45")
	Runtime type information. More...

	RKF45 (const ODESystem &ode, const dictionary &dict)
	Construct from ODESystem. More...

virtual	~RKF45 ()
	Destructor. More...

virtual bool	resize ()
	Resize the ODE solver. More...

virtual scalar	solve (const scalar x0, const scalarField &y0, const label li, const scalarField &dydx0, const scalar dx, scalarField &y) const
	Solve a single step dx and return the error. More...

virtual void	solve (scalar &x, scalarField &y, const label li, scalar &dxTry) const
	Solve the ODE system and the update the state. More...

virtual void	solve (scalar &x, scalarField &y, const label li, scalar &dxTry) const
	Inherit solve from ODESolver. More...

virtual void	solve (scalar &x, scalarField &y, const label li, stepState &step) const
	Inherit solve from ODESolver. More...

virtual void	solve (const scalar xStart, const scalar xEnd, scalarField &y, const label li, scalar &dxEst) const
	Inherit solve from ODESolver. More...

Public Member Functions inherited from ODESolver
	TypeName ("ODESolver")
	Runtime type information. More...

	declareRunTimeSelectionTable (autoPtr, ODESolver, dictionary,(const ODESystem &ode, const dictionary &dict),(ode, dict))

	ODESolver (const ODESystem &ode, const dictionary &dict)
	Construct for given ODESystem. More...

	ODESolver (const ODESystem &ode, const scalarField &absTol, const scalarField &relTol)
	Construct for given ODESystem specifying tolerances. More...

	ODESolver (const ODESolver &)=delete
	Disallow default bitwise copy construction. More...

virtual	~ODESolver ()
	Destructor. More...

label	nEqns () const
	Return the number of equations to solve. More...

scalarField &	absTol ()
	Return access to the absolute tolerance field. More...

scalarField &	relTol ()
	Return access to the relative tolerance field. More...

template<class Type >
void	resizeField (UList< Type > &f) const

void	resizeMatrix (scalarSquareMatrix &m) const

virtual void	solve (scalar &x, scalarField &y, const label li, stepState &step) const
	Solve the ODE system from the current state xStart, y. More...

virtual void	solve (const scalar xStart, const scalar xEnd, scalarField &y, const label li, scalar &dxEst) const
	Solve the ODE system from the current state xStart, y. More...

void	operator= (const ODESolver &)=delete
	Disallow default bitwise assignment. More...

Public Member Functions inherited from adaptiveSolver
	adaptiveSolver (const ODESystem &ode, const dictionary &dict)
	Construct from ODESystem. More...

virtual	~adaptiveSolver ()
	Destructor. More...

bool	resize (const label n)
	Resize the ODE solver. More...

void	solve (const ODESystem &ode, scalar &x, scalarField &y, const label li, scalar &dxTry) const
	Solve the ODE system and the update the state. More...

Additional Inherited Members
Static Public Member Functions inherited from ODESolver
static autoPtr< ODESolver >	New (const ODESystem &ode, const dictionary &dict)
	Select null constructed. More...

template<class Type >
static void	resizeField (UList< Type > &f, const label n)

Protected Member Functions inherited from ODESolver
scalar	normaliseError (const scalarField &y0, const scalarField &y, const scalarField &err) const
	Return the normalised scalar error. More...

Protected Attributes inherited from ODESolver
const ODESystem &	odes_
	Reference to ODESystem. More...

const label	maxN_
	Maximum size of the ODESystem. More...

label	n_
	Size of the ODESystem (adjustable) More...

scalarField	absTol_
	Absolute convergence tolerance per step. More...

scalarField	relTol_
	Relative convergence tolerance per step. More...

label	maxSteps_
	The maximum number of sub-steps allowed for the integration step. More...

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

Definition at line 66 of file RKF45.H.

Constructor & Destructor Documentation

◆ RKF45()

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

Construct from ODESystem.

Definition at line 75 of file RKF45.C.

◆ ~RKF45()

virtual ~RKF45 ( )

inlinevirtual

Destructor.

Definition at line 107 of file RKF45.H.

Member Function Documentation

◆ TypeName()

TypeName ( "RKF45" )

Runtime type information.

◆ resize()

bool resize ( )

virtual

Resize the ODE solver.

Implements ODESolver.

Definition at line 91 of file RKF45.C.

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

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◆ solve() [1/5]

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

virtual

Solve a single step dx and return the error.

Implements adaptiveSolver.

Definition at line 114 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,
		const label	li,
		scalar &	dxTry
	)		const

virtual

Solve the ODE system and the update the state.

Reimplemented from ODESolver.

Definition at line 183 of file RKF45.C.

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

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◆ solve() [3/5]

void solve

Inherit solve from ODESolver.

Definition at line 190 of file ODESolver.C.

◆ solve() [4/5]

void solve

Inherit solve from ODESolver.

Definition at line 204 of file ODESolver.C.

◆ solve() [5/5]

void solve

Inherit solve from ODESolver.

Definition at line 215 of file ODESolver.C.

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

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

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ RKF45()

◆ ~RKF45()

Member Function Documentation

◆ TypeName()

◆ resize()

◆ solve() [1/5]

◆ solve() [2/5]

◆ solve() [3/5]

◆ solve() [4/5]

◆ solve() [5/5]