Leapfrog time stepper. More...

#include <Tempus_StepperLeapfrog_decl.hpp>

Inheritance diagram for Tempus::StepperLeapfrog< Scalar >:

Public Member Functions
	StepperLeapfrog ()
	Default constructor. More...

	StepperLeapfrog (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &appModel, Teuchos::RCP< Teuchos::ParameterList > pList=Teuchos::null)
	Constructor. More...

Basic stepper methods
virtual void	setObserver (Teuchos::RCP< StepperObserver< Scalar > > obs=Teuchos::null)
	Set 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 std::string	getStepperType () const

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

virtual Scalar	getOrder () const

virtual Scalar	getOrderMin () const

virtual Scalar	getOrderMax () const

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

ParameterList methods
void	setParameterList (const Teuchos::RCP< Teuchos::ParameterList > &pl)

Teuchos::RCP < Teuchos::ParameterList >	getNonconstParameterList ()

Teuchos::RCP < Teuchos::ParameterList >	unsetParameterList ()

Teuchos::RCP< const Teuchos::ParameterList >	getValidParameters () const

Teuchos::RCP < Teuchos::ParameterList >	getDefaultParameters () const

Overridden from Teuchos::Describable
virtual std::string	description () const

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

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

virtual void	setNonConstModel (const Teuchos::RCP< Thyra::ModelEvaluator< Scalar > > &appModel)

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

virtual void	setSolver (std::string solverName)
	Set solver via ParameterList solver name. More...

virtual void	setSolver (Teuchos::RCP< Teuchos::ParameterList > solverPL=Teuchos::null)
	Set solver via solver ParameterList. More...

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 bool	getEmbedded () const

virtual void	setUseFSAL (bool a)

virtual bool	getUseFSAL () const

virtual void	setICConsistency (std::string s)

virtual std::string	getICConsistency () const

virtual void	setICConsistencyCheck (bool c)

virtual bool	getICConsistencyCheck () const

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...

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

Public Member Functions inherited from Tempus::Stepper< Scalar >
virtual void	modelWarning () const

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

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

void	validExplicitODE (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &model) const
	Validate that the model supports explicit ODE evaluation, f(x,t) [=xdot]. More...

void	validSecondOrderExplicitODE (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &model) const
	Validate that the model supports explicit second order ODE evaluation, f(x,xdot,t) [=xdotdot]. More...

void	validImplicitODE_DAE (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &model) const
	Validate ME supports implicit ODE/DAE evaluation, f(xdot,x,t) [= 0]. More...

void	validSecondOrderODE_DAE (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &model) const
	Validate ME supports 2nd order implicit ODE/DAE evaluation, f(xdotdot,xdot,x,t) [= 0]. More...

Teuchos::RCP < Teuchos::ParameterList >	defaultSolverParameters () const

Protected Attributes
Teuchos::RCP < StepperLeapfrogObserver < Scalar > >	stepperLFObserver_

Protected Attributes inherited from Tempus::StepperExplicit< Scalar >
Teuchos::RCP < Teuchos::ParameterList >	stepperPL_

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_

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

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

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

Detailed Description

template<class Scalar>
class Tempus::StepperLeapfrog< Scalar >

Leapfrog time stepper.

For the governing equation,

$M(t) \ddot{x} + K(t) x = F(t),$

one can write the explicit ODE system,

$\ddot{x} = f(x,t),$

where

$f(x,t) = \left(M(t)\right)^{-1} \left( F(t) - K(t) x \right).$

The Leapfrog stepper can be written as

$\begin{eqnarray*} x_{n+1} & = & x_{n} + \Delta t\, \dot{x}_{n+1/2} \\ \ddot{x}_{n+1} & = & f(x_{n+1},t_{n+1}) \\ \dot{x}_{n+3/2} & = & \dot{x}_{n+1/2} + \Delta t\, \ddot{x}_{n+1} \end{eqnarray*}$

where the position and velocity are leapfrogged over each other. On startup the velocity half-step can be obtained with

$\begin{eqnarray*} \dot{x}_{n+1/2} & = & \dot{x}_{n} + \frac{1}{2} \Delta t\, \ddot{x}_{n} \\ \dot{x}_{n+1/2} & = & \dot{x}_{n} + \frac{1}{2} \Delta t\, f(x_{n},t_{n}) \end{eqnarray*}$

and to complete the time step, the final velocity half-step is obtained with

$\begin{eqnarray*} \dot{x}_{n+1}&=&\dot{x}_{n+1/2} +\frac{1}{2} \Delta t\, \ddot{x}_{n+1} \\ \dot{x}_{n+1}&=&\dot{x}_{n+1/2} +\frac{1}{2} \Delta t\, f(x_{n+1},t_{n+1}) \end{eqnarray*}$

Algorithm

Beginning with $(x_n,\dot{x}_{n+1/2})$ or $(x_n,\dot{x}_{n})$ and/or ending with $(x_{n+1},\dot{x}_{n+3/2})$ or $(x_{n+1},\dot{x}_{n+1})$ , the algorithm for Leapfrog is

if "startup"
- $\ddot{x}_{n} \leftarrow f(x_{n},t_{n})$
- $\dot{x}_{n+1/2} \leftarrow \dot{x}_{n} + \frac{1}{2} \Delta t\, \ddot{x}_{n}$
$x_{n+1} \leftarrow x_{n} + \Delta t\, \dot{x}_{n+1/2}$
$\ddot{x}_{n+1} \leftarrow f(x_{n+1},t_{n+1})$
if "ending"
- $\dot{x}_{n+1} \leftarrow \dot{x}_{n+1/2} +\frac{1}{2} \Delta t\, \ddot{x}_{n+1}$
else
- $\dot{x}_{n+3/2} \leftarrow \dot{x}_{n+1/2} + \Delta t\, \ddot{x}_{n+1}$

The First-Step-As-Last (FSAL) principle is not used with Leapfrog because of the algorithm's prescribed order of solution update. The default is to set useFSAL=false, however useFSAL=true will also work (i.e., no-op), but issue a warning that it will have no affect.

Definition at line 76 of file Tempus_StepperLeapfrog_decl.hpp.

Constructor & Destructor Documentation

template<class Scalar >

Tempus::StepperLeapfrog< Scalar >::StepperLeapfrog ( )

Default constructor.

Constructs with a default ParameterList.
Can reset ParameterList with setParameterList().
Requires subsequent setModel() and initialize() calls before calling takeStep().

Definition at line 19 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

Tempus::StepperLeapfrog< Scalar >::StepperLeapfrog	(	const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &	appModel,
		Teuchos::RCP< Teuchos::ParameterList >	pList = `Teuchos::null`
	)

Constructor.

Definition at line 26 of file Tempus_StepperLeapfrog_impl.hpp.

Member Function Documentation

template<class Scalar >

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

virtual

Definition at line 192 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

std::string Tempus::StepperLeapfrog< Scalar >::description ( ) const

virtual

Definition at line 184 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

Teuchos::RCP< Teuchos::ParameterList > Tempus::StepperLeapfrog< Scalar >::getDefaultParameters ( ) const

virtual

Implements Tempus::Stepper< Scalar >.

Definition at line 239 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

Teuchos::RCP< Tempus::StepperState< Scalar > > Tempus::StepperLeapfrog< 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 175 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

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

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 118 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

Teuchos::RCP< Teuchos::ParameterList > Tempus::StepperLeapfrog< Scalar >::getNonconstParameterList ( )

Definition at line 254 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

virtual Scalar Tempus::StepperLeapfrog< Scalar >::getOrder ( ) const

inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 115 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

virtual Scalar Tempus::StepperLeapfrog< Scalar >::getOrderMax ( ) const

inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 117 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

virtual Scalar Tempus::StepperLeapfrog< Scalar >::getOrderMin ( ) const

inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 116 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

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

inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 129 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

virtual std::string Tempus::StepperLeapfrog< Scalar >::getStepperType ( ) const

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 110 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

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

Definition at line 225 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

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

virtual

Initialize during construction and after changing input parameters.

Implements Tempus::Stepper< Scalar >.

Definition at line 62 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

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

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 122 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

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

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 124 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

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

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 123 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

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

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 127 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

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

inlinevirtual

Reimplemented from Tempus::StepperExplicit< Scalar >.

Definition at line 126 of file Tempus_StepperLeapfrog_decl.hpp.

template<class Scalar >

void Tempus::StepperLeapfrog< 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 74 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

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

virtual

Set Observer.

Implements Tempus::Stepper< Scalar >.

Definition at line 42 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

void Tempus::StepperLeapfrog< Scalar >::setParameterList ( const Teuchos::RCP< Teuchos::ParameterList > & pl )

Definition at line 202 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

void Tempus::StepperLeapfrog< 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 99 of file Tempus_StepperLeapfrog_impl.hpp.

template<class Scalar >

Teuchos::RCP< Teuchos::ParameterList > Tempus::StepperLeapfrog< Scalar >::unsetParameterList ( )

Definition at line 262 of file Tempus_StepperLeapfrog_impl.hpp.

Member Data Documentation

template<class Scalar >

Teuchos::RCP<StepperLeapfrogObserver<Scalar> > Tempus::StepperLeapfrog< Scalar >::stepperLFObserver_

protected

Definition at line 150 of file Tempus_StepperLeapfrog_decl.hpp.

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

http://docs.trilinos.org/r12.16/packages/tempus/src/Tempus_StepperLeapfrog_decl.hpp
http://docs.trilinos.org/r12.16/packages/tempus/src/Tempus_StepperLeapfrog_impl.hpp

Public Member Functions

Protected Attributes

Detailed Description

template<class Scalar> class Tempus::StepperLeapfrog< Scalar >

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class Scalar>
class Tempus::StepperLeapfrog< Scalar >