Explicit Runge-Kutta time stepper. More...

#include <Tempus_StepperExplicitRK_decl.hpp>

Inheritance diagram for Tempus::StepperExplicitRK< Scalar >:

Public Member Functions
Teuchos::RCP< const Teuchos::ParameterList >	getValidParameters () const

virtual bool	isValidSetup (Teuchos::FancyOStream &out) const

Basic stepper methods
virtual void	setObserver (Teuchos::RCP< StepperObserver< Scalar > > obs=Teuchos::null)
	Set Observer. More...

virtual Teuchos::RCP < StepperObserver< Scalar > >	getObserver () const
	Get Observer. More...

virtual void	initialize ()
	Initialize during construction and after changing input parameters. More...

virtual void	setInitialConditions (const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory)
	Set the initial conditions and make them consistent. More...

virtual void	takeStep (const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory)
	Take the specified timestep, dt, and return true if successful. More...

virtual Teuchos::RCP < Tempus::StepperState< Scalar > >	getDefaultStepperState ()
	Get a default (initial) StepperState. More...

virtual Scalar	getInitTimeStep (const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory) const

virtual bool	isExplicit () const

virtual bool	isImplicit () const

virtual bool	isExplicitImplicit () const

virtual bool	isOneStepMethod () const

virtual bool	isMultiStepMethod () const

virtual OrderODE	getOrderODE () const

void	getValidParametersBasicERK (Teuchos::RCP< Teuchos::ParameterList > pl) const

virtual std::string	getDescription () const =0

Overridden from Teuchos::Describable
virtual void	describe (Teuchos::FancyOStream &out, const Teuchos::EVerbosityLevel verbLevel) const

Accessors methods
virtual void	setUseEmbedded (bool a)
	Use embedded if avialable. More...

virtual bool	getUseEmbedded () const

virtual bool	getUseEmbeddedDefault () const

Public Member Functions inherited from Tempus::StepperExplicit< Scalar >
virtual void	setModel (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &appModel)

virtual Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > >	getModel ()

virtual void	setSolver (Teuchos::RCP< Thyra::NonlinearSolverBase< Scalar > > solver)
	Set solver. More...

virtual Teuchos::RCP < Thyra::NonlinearSolverBase < Scalar > >	getSolver () const
	Get solver. More...

virtual void	setInitialGuess (Teuchos::RCP< const Thyra::VectorBase< Scalar > >)
	Pass initial guess to Newton solver (only relevant for implicit solvers) More...

virtual void	evaluateExplicitODE (Teuchos::RCP< Thyra::VectorBase< Scalar > > xDot, Teuchos::RCP< const Thyra::VectorBase< Scalar > > x, const Scalar time, const Teuchos::RCP< ExplicitODEParameters< Scalar > > &p)
	Evaluate xDot = f(x,t). More...

virtual void	evaluateExplicitODE (Teuchos::RCP< Thyra::VectorBase< Scalar > > xDotDot, Teuchos::RCP< const Thyra::VectorBase< Scalar > > x, Teuchos::RCP< const Thyra::VectorBase< Scalar > > xDot, const Scalar time, const Teuchos::RCP< ExplicitODEParameters< Scalar > > &p)
	Evaluate xDotDot = f(x, xDot, t). More...

Public Member Functions inherited from Tempus::Stepper< Scalar >
virtual void	setNonConstModel (const Teuchos::RCP< Thyra::ModelEvaluator< Scalar > > &)

virtual bool	isInitialized ()
	True if stepper's member data is initialized. More...

virtual void	checkInitialized ()
	Check initialization, and error out on failure. More...

void	setStepperType (std::string s)

std::string	getStepperType () const

void	setUseFSAL (bool a)

bool	getUseFSAL () const

virtual bool	getUseFSALDefault () const

void	setICConsistency (std::string s)

std::string	getICConsistency () const

virtual std::string	getICConsistencyDefault () const

void	setICConsistencyCheck (bool c)

bool	getICConsistencyCheck () const

virtual bool	getICConsistencyCheckDefault () const

virtual Teuchos::RCP < Thyra::VectorBase< Scalar > >	getStepperX (Teuchos::RCP< SolutionState< Scalar > > state)
	Get x from SolutionState or Stepper storage. More...

virtual Teuchos::RCP < Thyra::VectorBase< Scalar > >	getStepperXDot (Teuchos::RCP< SolutionState< Scalar > > state)
	Get xDot from SolutionState or Stepper storage. More...

virtual Teuchos::RCP < Thyra::VectorBase< Scalar > >	getStepperXDotDot (Teuchos::RCP< SolutionState< Scalar > > state)
	Get xDotDot from SolutionState or Stepper storage. More...

virtual std::string	description () const

virtual void	createSubSteppers (std::vector< Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > >)

Public Member Functions inherited from Tempus::StepperRKBase< Scalar >
virtual Teuchos::RCP< const RKButcherTableau< Scalar > >	getTableau () const

virtual Scalar	getOrder () const

virtual Scalar	getOrderMin () const

virtual Scalar	getOrderMax () const

virtual int	getNumberOfStages () const

virtual int	getStageNumber () const

virtual void	setStageNumber (int s)

virtual Teuchos::RCP < Thyra::VectorBase< Scalar > >	getStageX ()

virtual Teuchos::RCP< const Thyra::VectorBase< Scalar > >	getStageX () const

virtual void	setAppAction (Teuchos::RCP< StepperRKAppAction< Scalar > > appAction)

virtual Teuchos::RCP < StepperRKAppAction< Scalar > >	getAppAction () const

Protected Member Functions
virtual void	setupDefault ()
	Default setup for constructor. More...

virtual void	setup (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &appModel, const Teuchos::RCP< StepperRKObserverComposite< Scalar > > &obs, bool useFSAL, std::string ICConsistency, bool ICConsistencyCheck, bool useEmbedded)
	Setup for constructor. More...

virtual void	setup (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &appModel, bool useFSAL, std::string ICConsistency, bool ICConsistencyCheck, bool useEmbedded, const Teuchos::RCP< StepperRKAppAction< Scalar > > &stepperRKAppAction)

virtual void	setupTableau ()=0

Protected Member Functions inherited from Tempus::Stepper< Scalar >
virtual void	setStepperX (Teuchos::RCP< Thyra::VectorBase< Scalar > > x)
	Set x for Stepper storage. More...

virtual void	setStepperXDot (Teuchos::RCP< Thyra::VectorBase< Scalar > > xDot)
	Set xDot for Stepper storage. More...

virtual void	setStepperXDotDot (Teuchos::RCP< Thyra::VectorBase< Scalar > > xDotDot)
	Set x for Stepper storage. More...

Protected Attributes
std::vector< Teuchos::RCP < Thyra::VectorBase< Scalar > > >	stageXDot_

Teuchos::RCP < StepperRKObserverComposite < Scalar > >	stepperObserver_

bool	useEmbedded_

Teuchos::RCP < Thyra::VectorBase< Scalar > >	ee_

Teuchos::RCP < Thyra::VectorBase< Scalar > >	abs_u0

Teuchos::RCP < Thyra::VectorBase< Scalar > >	abs_u

Teuchos::RCP < Thyra::VectorBase< Scalar > >	sc

Protected Attributes inherited from Tempus::StepperExplicit< Scalar >
Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > >	appModel_
	Explicit ODE ModelEvaluator. More...

Thyra::ModelEvaluatorBase::InArgs < Scalar >	inArgs_

Thyra::ModelEvaluatorBase::OutArgs < Scalar >	outArgs_

Teuchos::RCP< StepperObserver < Scalar > >	stepperObserver_

Protected Attributes inherited from Tempus::Stepper< Scalar >
bool	isInitialized_ = false
	True if stepper's member data is initialized. More...

Protected Attributes inherited from Tempus::StepperRKBase< Scalar >
Teuchos::RCP< RKButcherTableau < Scalar > >	tableau_

int	stageNumber_
	The current Runge-Kutta stage number, {0,...,s-1}. -1 indicates outside stage loop. More...

Teuchos::RCP < Thyra::VectorBase< Scalar > >	stageX_

Teuchos::RCP < StepperRKAppAction< Scalar > >	stepperRKAppAction_

Detailed Description

template<class Scalar>
class Tempus::StepperExplicitRK< Scalar >

Explicit Runge-Kutta time stepper.

For the explicit ODE system,

$\dot{x} = \bar{f}(x,t),$

the general explicit Runge-Kutta method for $s$ -stages can be written as

$X_{i} = x_{n-1} + \Delta t\,\sum_{j=1}^{i-1} a_{ij}\,\bar{f}(X_{j},t_{n-1}+c_{j}\Delta t)$

$x_{n} = x_{n-1} + \Delta t\,\sum_{i=1}^{s}b_{i}\,\bar{f}(X_{i},t_{n-1}+c_{i}\Delta t)$

where $X_{i}$ are intermediate approximations to the solution at times, $t_{n-1}+c_{i}\Delta t$ , (stage solutions) which may be correct to a lower order of accuracy than the solution, $x_{n}$ . We should note that these lower-order approximations are combined through $b_{i}$ so that error terms cancel out and produce a more accurate solution. Note for explicit RK that $a_{ij}=0$ for $j \leq i$ and does not require any solves. Note that the stage time derivatives are

$\dot{X}_{i} = \bar{f}(X_{i},t_{n-1}+c_{i}\Delta t),$

and the time derivative by definition is

$\dot{x}_{n} = \bar{f}(x_{n},t_{n}),$

Algorithm The single-timestep algorithm for Explicit RK is

$\begin{algorithm} \renewcommand{\thealgorithm}{} \caption{Explicit RK with the application-action locations indicated.} \begin{algorithmic}[1] \State {\it appAction.execute(solutionHistory, stepper, BEGIN\_STEP)} \State $X \leftarrow x_{n-1}$ \Comment Set initial guess to last timestep. \For {$i = 0 \ldots s-1$} \State {\it appAction.execute(solutionHistory, stepper, BEGIN\_STAGE)} \State {\it appAction.execute(solutionHistory, stepper, BEFORE\_SOLVE)} \If { i==0 and useFSAL and (previous step not failed) } \State tmp = $\dot{X}_0$ \State $\dot{X}_0 = \dot{X}_s$ \State $\dot{X}_s$ = tmp \State {\bf continue} \Else \State $X \leftarrow x_{n-1} + \Delta t\,\sum_{j=1}^{i-1} a_{ij}\,\dot{X}_j$ \State {\it appAction.execute(solutionHistory, stepper, AFTER\_SOLVE)} \State {\it appAction.execute(solutionHistory, stepper, BEFORE\_EXPLICIT\_EVAL)} \State $\dot{X}_i \leftarrow \bar{f}(X_i,t_{n-1}+c_i\Delta t)$ \EndIf \State {\it appAction.execute(solutionHistory, stepper, END\_STAGE)} \EndFor \State $x_n \leftarrow x_{n-1} + \Delta t\,\sum_{i=1}^{s}b_i\,\dot{X}_i$ \State {\it appAction.execute(solutionHistory, stepper, END\_STEP)} \end{algorithmic} \end{algorithm}$

For Explicit RK, FSAL requires $c_1 = 0$ , $c_s = 1$ , and be stiffly accurate ( $a_{sj} = b_j$ ). An example of this is the Bogacki-Shampine 3(2) method.

$\begin{array}{c|cccc} 0 & 0 & & & \\ 1/3 & 1/2 & 0 & & \\ 2/3 & 0 & 3/4 & 0 & \\ 1 & 2/9 & 1/3 & 4/9 & 0 \\ \hline & 2/9 & 1/3 & 4/9 & 0 \\ & 7/24 & 1/4 & 1/3 & 1/8 \end{array}$

Definition at line 98 of file Tempus_StepperExplicitRK_decl.hpp.

Member Function Documentation

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::describe	(	Teuchos::FancyOStream &	out,
		const Teuchos::EVerbosityLevel	verbLevel
	)		const

virtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 446 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

Teuchos::RCP< Tempus::StepperState< Scalar > > Tempus::StepperExplicitRK< Scalar >::getDefaultStepperState ( )

virtual

Get a default (initial) StepperState.

Provide a StepperState to the SolutionState. This Stepper does not have any special state data, so just provide the base class StepperState with the Stepper description. This can be checked to ensure that the input StepperState can be used by this Stepper.

Implements Tempus::Stepper< Scalar >.

Definition at line 437 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

virtual std::string Tempus::StepperExplicitRK< Scalar >::getDescription ( ) const

pure virtual

template<class Scalar >

Scalar Tempus::StepperExplicitRK< Scalar >::getInitTimeStep ( const Teuchos::RCP< SolutionHistory< Scalar > > & solutionHistory ) const

virtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 95 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

virtual Teuchos::RCP<StepperObserver<Scalar> > Tempus::StepperExplicitRK< Scalar >::getObserver ( ) const

inlinevirtual

Get Observer.

Reimplemented from Tempus::Stepper< Scalar >.

Definition at line 110 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

virtual OrderODE Tempus::StepperExplicitRK< Scalar >::getOrderODE ( ) const

inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 136 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

virtual bool Tempus::StepperExplicitRK< Scalar >::getUseEmbedded ( ) const

inlinevirtual

Definition at line 156 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

virtual bool Tempus::StepperExplicitRK< Scalar >::getUseEmbeddedDefault ( ) const

inlinevirtual

Definition at line 157 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

Teuchos::RCP< const Teuchos::ParameterList > Tempus::StepperExplicitRK< Scalar >::getValidParameters ( ) const

virtual

Implements Tempus::Stepper< Scalar >.

Reimplemented in Tempus::StepperERK_General< Scalar >.

Definition at line 506 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::getValidParametersBasicERK ( Teuchos::RCP< Teuchos::ParameterList > pl ) const

Definition at line 178 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::initialize ( )

virtual

Initialize during construction and after changing input parameters.

Reimplemented from Tempus::Stepper< Scalar >.

Definition at line 223 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

virtual bool Tempus::StepperExplicitRK< Scalar >::isExplicit ( ) const

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 129 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

virtual bool Tempus::StepperExplicitRK< Scalar >::isExplicitImplicit ( ) const

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 131 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

virtual bool Tempus::StepperExplicitRK< Scalar >::isImplicit ( ) const

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 130 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

virtual bool Tempus::StepperExplicitRK< Scalar >::isMultiStepMethod ( ) const

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 134 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

virtual bool Tempus::StepperExplicitRK< Scalar >::isOneStepMethod ( ) const

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 133 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

bool Tempus::StepperExplicitRK< Scalar >::isValidSetup ( Teuchos::FancyOStream & out ) const

virtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 477 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::setInitialConditions ( const Teuchos::RCP< SolutionHistory< Scalar > > & solutionHistory )

virtual

Set the initial conditions and make them consistent.

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 253 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::setObserver ( Teuchos::RCP< StepperObserver< Scalar > > obs = Teuchos::null )

virtual

Set Observer.

Reimplemented from Tempus::Stepper< Scalar >.

Definition at line 192 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::setup	(	const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &	appModel,
		const Teuchos::RCP< StepperRKObserverComposite< Scalar > > &	obs,
		bool	useFSAL,
		std::string	ICConsistency,
		bool	ICConsistencyCheck,
		bool	useEmbedded
	)

protectedvirtual

Setup for constructor.

Definition at line 40 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::setup	(	const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &	appModel,
		bool	useFSAL,
		std::string	ICConsistency,
		bool	ICConsistencyCheck,
		bool	useEmbedded,
		const Teuchos::RCP< StepperRKAppAction< Scalar > > &	stepperRKAppAction
	)

protectedvirtual

Definition at line 67 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::setupDefault ( )

protectedvirtual

Default setup for constructor.

Definition at line 22 of file Tempus_StepperExplicitRK_impl.hpp.

template<class Scalar >

virtual void Tempus::StepperExplicitRK< Scalar >::setupTableau ( )

protectedpure virtual

template<class Scalar >

virtual void Tempus::StepperExplicitRK< Scalar >::setUseEmbedded ( bool a )

inlinevirtual

Use embedded if avialable.

Definition at line 155 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

void Tempus::StepperExplicitRK< Scalar >::takeStep ( const Teuchos::RCP< SolutionHistory< Scalar > > & solutionHistory )

virtual

Take the specified timestep, dt, and return true if successful.

Implements Tempus::Stepper< Scalar >.

Definition at line 269 of file Tempus_StepperExplicitRK_impl.hpp.

Member Data Documentation

template<class Scalar >

Teuchos::RCP<Thyra::VectorBase<Scalar> > Tempus::StepperExplicitRK< Scalar >::abs_u

protected

Definition at line 197 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

Teuchos::RCP<Thyra::VectorBase<Scalar> > Tempus::StepperExplicitRK< Scalar >::abs_u0

protected

Definition at line 196 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

Teuchos::RCP<Thyra::VectorBase<Scalar> > Tempus::StepperExplicitRK< Scalar >::ee_

protected

Definition at line 195 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

Teuchos::RCP<Thyra::VectorBase<Scalar> > Tempus::StepperExplicitRK< Scalar >::sc

protected

Definition at line 198 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

std::vector<Teuchos::RCP<Thyra::VectorBase<Scalar> > > Tempus::StepperExplicitRK< Scalar >::stageXDot_

protected

Definition at line 187 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

Teuchos::RCP<StepperRKObserverComposite<Scalar> > Tempus::StepperExplicitRK< Scalar >::stepperObserver_

protected

Definition at line 190 of file Tempus_StepperExplicitRK_decl.hpp.

template<class Scalar >

bool Tempus::StepperExplicitRK< Scalar >::useEmbedded_

protected

Definition at line 194 of file Tempus_StepperExplicitRK_decl.hpp.

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

http://docs.trilinos.org/r13.0/packages/tempus/src/Tempus_StepperExplicitRK_decl.hpp
http://docs.trilinos.org/r13.0/packages/tempus/src/Tempus_StepperExplicitRK_impl.hpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

template<class Scalar> class Tempus::StepperExplicitRK< Scalar >

Member Function Documentation

Member Data Documentation

template<class Scalar>
class Tempus::StepperExplicitRK< Scalar >