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Tempus::StepperTrapezoidal< Scalar > Class Template Reference

Trapezoidal method time stepper. More...

#include <Tempus_StepperTrapezoidal_decl.hpp>

Inheritance diagram for Tempus::StepperTrapezoidal< Scalar >:
Tempus::StepperImplicit< Scalar > Tempus::Stepper< Scalar >

Public Member Functions

 StepperTrapezoidal ()
 Default constructor. More...
 
 StepperTrapezoidal (const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &appModel, const Teuchos::RCP< StepperObserver< Scalar > > &obs, const Teuchos::RCP< Thyra::NonlinearSolverBase< Scalar > > &solver, bool useFSAL, std::string ICConsistency, bool ICConsistencyCheck, bool zeroInitialGuess)
 Constructor. More...
 
virtual Scalar getAlpha (const Scalar dt) const
 Return alpha = d(xDot)/dx. More...
 
virtual Scalar getBeta (const Scalar) const
 Return beta = d(x)/dx. More...
 
Teuchos::RCP< const
Teuchos::ParameterList > 
getValidParameters () const
 
virtual bool getUseFSALDefault () const
 
virtual std::string getICConsistencyDefault () 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 getOrder () const
 
virtual Scalar getOrderMin () const
 
virtual Scalar getOrderMax () 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
 
Overridden from Teuchos::Describable
virtual void describe (Teuchos::FancyOStream &out, const Teuchos::EVerbosityLevel verbLevel) const
 
- Public Member Functions inherited from Tempus::StepperImplicit< 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 Teuchos::RCP< const
WrapperModelEvaluator< Scalar > > 
getWrapperModel ()
 
virtual void setSolver (Teuchos::RCP< Thyra::NonlinearSolverBase< Scalar > > solver=Teuchos::null)
 Set solver. More...
 
virtual Teuchos::RCP
< Thyra::NonlinearSolverBase
< Scalar > > 
getSolver () const
 Get solver. More...
 
const Thyra::SolveStatus< Scalar > solveImplicitODE (const Teuchos::RCP< Thyra::VectorBase< Scalar > > &x)
 Solve problem using x in-place. (Needs to be deprecated!) More...
 
const Thyra::SolveStatus< Scalar > solveImplicitODE (const Teuchos::RCP< Thyra::VectorBase< Scalar > > &x, const Teuchos::RCP< Thyra::VectorBase< Scalar > > &xDot, const Scalar time, const Teuchos::RCP< ImplicitODEParameters< Scalar > > &p)
 Solve implicit ODE, f(x, xDot, t, p) = 0. More...
 
void evaluateImplicitODE (Teuchos::RCP< Thyra::VectorBase< Scalar > > &f, const Teuchos::RCP< Thyra::VectorBase< Scalar > > &x, const Teuchos::RCP< Thyra::VectorBase< Scalar > > &xDot, const Scalar time, const Teuchos::RCP< ImplicitODEParameters< Scalar > > &p)
 Evaluate implicit ODE residual, f(x, xDot, t, p). More...
 
virtual void setInitialGuess (Teuchos::RCP< const Thyra::VectorBase< Scalar > > initial_guess)
 Pass initial guess to Newton solver (only relevant for implicit solvers) More...
 
virtual void setZeroInitialGuess (bool zIG)
 Set parameter so that the initial guess is set to zero (=True) or use last timestep (=False). More...
 
virtual bool getZeroInitialGuess () const
 
virtual Scalar getInitTimeStep (const Teuchos::RCP< SolutionHistory< Scalar > > &) const
 
virtual void setStepperXDot (Teuchos::RCP< Thyra::VectorBase< Scalar > > xDot)
 Set xDot for 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...
 
- Public Member Functions inherited from Tempus::Stepper< Scalar >
void setStepperType (std::string s)
 
std::string getStepperType () const
 
void setUseFSAL (bool a)
 
bool getUseFSAL () const
 
void setICConsistency (std::string s)
 
std::string getICConsistency () const
 
void setICConsistencyCheck (bool c)
 
bool getICConsistencyCheck () const
 
virtual bool getICConsistencyCheckDefault () const
 
virtual std::string description () const
 
virtual void createSubSteppers (std::vector< Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > >)
 

Private Attributes

Teuchos::RCP
< StepperTrapezoidalObserver
< Scalar > > 
stepperTrapObserver_
 

Additional Inherited Members

- Protected Attributes inherited from Tempus::StepperImplicit< Scalar >
Teuchos::RCP
< WrapperModelEvaluator
< Scalar > > 
wrapperModel_
 
Teuchos::RCP
< Thyra::NonlinearSolverBase
< Scalar > > 
solver_
 
Teuchos::RCP< const
Thyra::VectorBase< Scalar > > 
initial_guess_
 
bool zeroInitialGuess_
 
Teuchos::RCP< StepperObserver
< Scalar > > 
stepperObserver_
 
Teuchos::RCP
< Thyra::VectorBase< Scalar > > 
stepperXDot_
 
Teuchos::RCP
< Thyra::VectorBase< Scalar > > 
stepperXDotDot_
 

Detailed Description

template<class Scalar>
class Tempus::StepperTrapezoidal< Scalar >

Trapezoidal method time stepper.

For the implicit ODE system, $\mathcal{F}(\dot{x},x,t) = 0$, the solution, $\dot{x}$ and $x$, is determined using a solver (e.g., a non-linear solver, like NOX).

Algorithm The single-timestep algorithm for Trapezoidal method is simply,

  • Solve $f(\dot{x}=(x_n-x_{n-1})/(\Delta t_n/2) - \dot{x}_{n-1}, x_n, t_n)=0$ for $x_n$
  • $\dot{x}_n \leftarrow (x_n-x_{n-1})/(\Delta t_n/2) - \dot{x}_{n-1}$

The First-Step-As-Last (FSAL) principle is required for the Trapezoidal Stepper (i.e., useFSAL=true)! There are at least two ways around this, but are not implemented.

  • Do a solve for xDotOld, xDot_{n-1}, at each time step as for the initial conditions. This is expensive since you would be doing two solves every time step.
  • Use evaluateExplicitODE to get xDot_{n-1} if the application provides it. Explicit evaluations are cheaper but requires the application to implement xDot = f(x,t).

Definition at line 41 of file Tempus_StepperTrapezoidal_decl.hpp.

Constructor & Destructor Documentation

template<class Scalar >
Tempus::StepperTrapezoidal< Scalar >::StepperTrapezoidal ( )

Default constructor.

Requires subsequent setModel(), setSolver() and initialize() calls before calling takeStep().

Definition at line 26 of file Tempus_StepperTrapezoidal_impl.hpp.

template<class Scalar >
Tempus::StepperTrapezoidal< Scalar >::StepperTrapezoidal ( const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &  appModel,
const Teuchos::RCP< StepperObserver< Scalar > > &  obs,
const Teuchos::RCP< Thyra::NonlinearSolverBase< Scalar > > &  solver,
bool  useFSAL,
std::string  ICConsistency,
bool  ICConsistencyCheck,
bool  zeroInitialGuess 
)

Constructor.

Definition at line 39 of file Tempus_StepperTrapezoidal_impl.hpp.

Member Function Documentation

template<class Scalar >
void Tempus::StepperTrapezoidal< Scalar >::describe ( Teuchos::FancyOStream &  out,
const Teuchos::EVerbosityLevel  verbLevel 
) const
virtual

Definition at line 198 of file Tempus_StepperTrapezoidal_impl.hpp.

template<class Scalar >
virtual Scalar Tempus::StepperTrapezoidal< Scalar >::getAlpha ( const Scalar  dt) const
inlinevirtual

Return alpha = d(xDot)/dx.

Implements Tempus::StepperImplicit< Scalar >.

Definition at line 97 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual Scalar Tempus::StepperTrapezoidal< Scalar >::getBeta ( const Scalar  ) const
inlinevirtual

Return beta = d(x)/dx.

Implements Tempus::StepperImplicit< Scalar >.

Definition at line 99 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
Teuchos::RCP< Tempus::StepperState< Scalar > > Tempus::StepperTrapezoidal< 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 189 of file Tempus_StepperTrapezoidal_impl.hpp.

template<class Scalar >
virtual std::string Tempus::StepperTrapezoidal< Scalar >::getICConsistencyDefault ( ) const
inlinevirtual

Reimplemented from Tempus::Stepper< Scalar >.

Definition at line 110 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual Teuchos::RCP<StepperObserver<Scalar> > Tempus::StepperTrapezoidal< Scalar >::getObserver ( ) const
inlinevirtual

Get Observer.

Implements Tempus::Stepper< Scalar >.

Definition at line 67 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual Scalar Tempus::StepperTrapezoidal< Scalar >::getOrder ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 83 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual Scalar Tempus::StepperTrapezoidal< Scalar >::getOrderMax ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 85 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual Scalar Tempus::StepperTrapezoidal< Scalar >::getOrderMin ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 84 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual OrderODE Tempus::StepperTrapezoidal< Scalar >::getOrderODE ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 93 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual bool Tempus::StepperTrapezoidal< Scalar >::getUseFSALDefault ( ) const
inlinevirtual

Reimplemented from Tempus::Stepper< Scalar >.

Definition at line 109 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
Teuchos::RCP< const Teuchos::ParameterList > Tempus::StepperTrapezoidal< Scalar >::getValidParameters ( ) const
virtual

Implements Tempus::Stepper< Scalar >.

Definition at line 209 of file Tempus_StepperTrapezoidal_impl.hpp.

template<class Scalar >
void Tempus::StepperTrapezoidal< Scalar >::initialize ( )
virtual

Initialize during construction and after changing input parameters.

Implements Tempus::Stepper< Scalar >.

Definition at line 88 of file Tempus_StepperTrapezoidal_impl.hpp.

template<class Scalar >
virtual bool Tempus::StepperTrapezoidal< Scalar >::isExplicit ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 87 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual bool Tempus::StepperTrapezoidal< Scalar >::isExplicitImplicit ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 89 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual bool Tempus::StepperTrapezoidal< Scalar >::isImplicit ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 88 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual bool Tempus::StepperTrapezoidal< Scalar >::isMultiStepMethod ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 92 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
virtual bool Tempus::StepperTrapezoidal< Scalar >::isOneStepMethod ( ) const
inlinevirtual

Implements Tempus::Stepper< Scalar >.

Definition at line 91 of file Tempus_StepperTrapezoidal_decl.hpp.

template<class Scalar >
void Tempus::StepperTrapezoidal< Scalar >::setInitialConditions ( const Teuchos::RCP< SolutionHistory< Scalar > > &  solutionHistory)
virtual

Set the initial conditions and make them consistent.

Reimplemented from Tempus::StepperImplicit< Scalar >.

Definition at line 98 of file Tempus_StepperTrapezoidal_impl.hpp.

template<class Scalar >
void Tempus::StepperTrapezoidal< Scalar >::setObserver ( Teuchos::RCP< StepperObserver< Scalar > >  obs = Teuchos::null)
virtual

Set Observer.

Implements Tempus::Stepper< Scalar >.

Definition at line 66 of file Tempus_StepperTrapezoidal_impl.hpp.

template<class Scalar >
void Tempus::StepperTrapezoidal< 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 125 of file Tempus_StepperTrapezoidal_impl.hpp.

Member Data Documentation

template<class Scalar >
Teuchos::RCP<StepperTrapezoidalObserver<Scalar> > Tempus::StepperTrapezoidal< Scalar >::stepperTrapObserver_
private

Definition at line 114 of file Tempus_StepperTrapezoidal_decl.hpp.


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