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Time Integration
Tempus::StepperBackwardEuler< Scalar > Class Template Reference

Backward Euler time stepper. More...

#include <Tempus_StepperBackwardEuler_decl.hpp>

Inheritance diagram for Tempus::StepperBackwardEuler< Scalar >:
Tempus::StepperImplicit< Scalar > Tempus::StepperOptimizationInterface< Scalar > Tempus::Stepper< Scalar >

Public Member Functions

 StepperBackwardEuler (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...
 
void setPredictor (std::string predictorName)
 Set the predictor. More...
 
void setPredictor (Teuchos::RCP< Teuchos::ParameterList >predPL=Teuchos::null)
 Set the predictor to the supplied Parameter sublist. This adds a new predictor Parameter sublist to the Stepper's ParameterList. If the predictor sublist is null, it tests if the predictor is set in the Stepper's ParameterList. More...
 
virtual void initialize ()
 Initialize during construction and after changing input parameters. More...
 
virtual void takeStep (const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory)
 Take the specified timestep, dt, and return true if successful. More...
 
virtual void setInitialGuess (Teuchos::RCP< const Thyra::VectorBase< Scalar > > initial_guess)
 Pass initial guess to Newton solver. 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 void computePredictor (const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory)
 Compute predictor given the supplied stepper. More...
 
virtual Teuchos::RCP< Thyra::VectorBase< Scalar > > getXDotTemp (Teuchos::RCP< const Thyra::VectorBase< Scalar > > x) const
 Provide temporary xDot memory for Stepper if SolutionState doesn't. More...
 
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::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 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 std::string getStepperType () const
 
const Thyra::SolveStatus< Scalar > solveImplicitODE (const Teuchos::RCP< Thyra::VectorBase< Scalar > > &x)
 Solve problem using x in-place. 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 bool getEmbedded () const
 
virtual Scalar getInitTimeStep (const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory) const
 
- Public Member Functions inherited from Tempus::Stepper< Scalar >
virtual void createSubSteppers (std::vector< Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > > models)
 
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
 
- Public Member Functions inherited from Tempus::StepperOptimizationInterface< Scalar >
 StepperOptimizationInterface ()
 
virtual ~StepperOptimizationInterface ()
 

Implementation of StepperOptimizationInterface

Teuchos::RCP< Stepper< Scalar > > predictorStepper_
 
Teuchos::RCP< StepperObserver< Scalar > > stepperObserver_
 
Teuchos::RCP< StepperBackwardEulerObserver< Scalar > > stepperBEObserver_
 
Teuchos::RCP< Thyra::VectorBase< Scalar > > xDotTemp_
 
Teuchos::RCP< const Thyra::VectorBase< Scalar > > initial_guess_
 
virtual int stencilLength () const
 Return the number of solution vectors in the time step stencil. More...
 
virtual void computeStepResidual (Thyra::VectorBase< Scalar > &residual, const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &x, const Teuchos::Array< Scalar > &t, const Thyra::VectorBase< Scalar > &p, const int param_index) const
 Compute time step residual. More...
 
virtual void computeStepJacobian (Thyra::LinearOpBase< Scalar > &jacobian, const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &x, const Teuchos::Array< Scalar > &t, const Thyra::VectorBase< Scalar > &p, const int param_index, const int deriv_index) const
 Compute time step Jacobian. More...
 
virtual void computeStepParamDeriv (Thyra::LinearOpBase< Scalar > &deriv, const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &x, const Teuchos::Array< Scalar > &t, const Thyra::VectorBase< Scalar > &p, const int param_index) const
 Compute time step derivative w.r.t. model parameters. More...
 
virtual void computeStepSolver (Thyra::LinearOpWithSolveBase< Scalar > &jacobian_solver, const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &x, const Teuchos::Array< Scalar > &t, const Thyra::VectorBase< Scalar > &p, const int param_index) const
 Compute time step Jacobian solver. More...
 
 StepperBackwardEuler ()
 Default Constructor – not allowed. More...
 
void computeStepResidDerivImpl (const Thyra::ModelEvaluatorBase::OutArgs< Scalar > &outArgs, const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &x, const Teuchos::Array< Scalar > &t, const Thyra::VectorBase< Scalar > &p, const int param_index, const int deriv_index=0) const
 Implementation of computeStep*() methods. More...
 

Additional Inherited Members

- Protected Attributes inherited from Tempus::StepperImplicit< Scalar >
Teuchos::RCP< Teuchos::ParameterList > stepperPL_
 
Teuchos::RCP< WrapperModelEvaluator< Scalar > > wrapperModel_
 
Teuchos::RCP< Thyra::NonlinearSolverBase< Scalar > > solver_
 
Teuchos::RCP< const Thyra::VectorBase< Scalar > > initial_guess_
 

Detailed Description

template<class Scalar>
class Tempus::StepperBackwardEuler< Scalar >

Backward Euler 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 Backward Euler is simply,

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

Definition at line 33 of file Tempus_StepperBackwardEuler_decl.hpp.

Constructor & Destructor Documentation

◆ StepperBackwardEuler() [1/2]

template<class Scalar >
Tempus::StepperBackwardEuler< Scalar >::StepperBackwardEuler ( const Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > &  appModel,
Teuchos::RCP< Teuchos::ParameterList >  pList = Teuchos::null 
)

Constructor.

Definition at line 27 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ StepperBackwardEuler() [2/2]

template<class Scalar>
Tempus::StepperBackwardEuler< Scalar >::StepperBackwardEuler ( )
private

Default Constructor – not allowed.

Member Function Documentation

◆ computePredictor()

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

Compute predictor given the supplied stepper.

Definition at line 221 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ computeStepJacobian()

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::computeStepJacobian ( Thyra::LinearOpBase< Scalar > &  jacobian,
const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &  x,
const Teuchos::Array< Scalar > &  t,
const Thyra::VectorBase< Scalar > &  p,
const int  param_index,
const int  deriv_index 
) const
virtual

Compute time step Jacobian.

deriv_index determines which component of x the derivative should be computed with respect to.

Implements Tempus::StepperOptimizationInterface< Scalar >.

Definition at line 381 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ computeStepParamDeriv()

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::computeStepParamDeriv ( Thyra::LinearOpBase< Scalar > &  deriv,
const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &  x,
const Teuchos::Array< Scalar > &  t,
const Thyra::VectorBase< Scalar > &  p,
const int  param_index 
) const
virtual

Compute time step derivative w.r.t. model parameters.

Implements Tempus::StepperOptimizationInterface< Scalar >.

Definition at line 398 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ computeStepResidDerivImpl()

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::computeStepResidDerivImpl ( const Thyra::ModelEvaluatorBase::OutArgs< Scalar > &  outArgs,
const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &  x,
const Teuchos::Array< Scalar > &  t,
const Thyra::VectorBase< Scalar > &  p,
const int  param_index,
const int  deriv_index = 0 
) const
private

Implementation of computeStep*() methods.

Definition at line 431 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ computeStepResidual()

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::computeStepResidual ( Thyra::VectorBase< Scalar > &  residual,
const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &  x,
const Teuchos::Array< Scalar > &  t,
const Thyra::VectorBase< Scalar > &  p,
const int  param_index 
) const
virtual

Compute time step residual.

Implements Tempus::StepperOptimizationInterface< Scalar >.

Definition at line 366 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ computeStepSolver()

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::computeStepSolver ( Thyra::LinearOpWithSolveBase< Scalar > &  jacobian_solver,
const Teuchos::Array< Teuchos::RCP< const Thyra::VectorBase< Scalar > > > &  x,
const Teuchos::Array< Scalar > &  t,
const Thyra::VectorBase< Scalar > &  p,
const int  param_index 
) const
virtual

Compute time step Jacobian solver.

Derivative is always w.r.t. the most current solution vector

Implements Tempus::StepperOptimizationInterface< Scalar >.

Definition at line 415 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ describe()

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

Definition at line 264 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ description()

template<class Scalar >
std::string Tempus::StepperBackwardEuler< Scalar >::description ( ) const
virtual

Definition at line 256 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ getDefaultParameters()

template<class Scalar >
Teuchos::RCP< Teuchos::ParameterList > Tempus::StepperBackwardEuler< Scalar >::getDefaultParameters ( ) const
virtual

Implements Tempus::Stepper< Scalar >.

Definition at line 320 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ getDefaultStepperState()

template<class Scalar >
Teuchos::RCP< Tempus::StepperState< Scalar > > Tempus::StepperBackwardEuler< 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 247 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ getNonconstParameterList()

template<class Scalar >
Teuchos::RCP< Teuchos::ParameterList > Tempus::StepperBackwardEuler< Scalar >::getNonconstParameterList ( )

Definition at line 340 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ getOrder()

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

Implements Tempus::Stepper< Scalar >.

Definition at line 66 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ getOrderMax()

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

Implements Tempus::Stepper< Scalar >.

Definition at line 68 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ getOrderMin()

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

Implements Tempus::Stepper< Scalar >.

Definition at line 67 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ getValidParameters()

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

Definition at line 305 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ getXDotTemp()

template<class Scalar >
Teuchos::RCP< Thyra::VectorBase< Scalar > > Tempus::StepperBackwardEuler< Scalar >::getXDotTemp ( Teuchos::RCP< const Thyra::VectorBase< Scalar > >  x) const
virtual

Provide temporary xDot memory for Stepper if SolutionState doesn't.

Definition at line 211 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ initialize()

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

Initialize during construction and after changing input parameters.

Implements Tempus::Stepper< Scalar >.

Definition at line 124 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ isExplicit()

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

Implements Tempus::Stepper< Scalar >.

Definition at line 70 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ isExplicitImplicit()

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

Implements Tempus::Stepper< Scalar >.

Definition at line 72 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ isImplicit()

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

Implements Tempus::Stepper< Scalar >.

Definition at line 71 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ isMultiStepMethod()

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

Implements Tempus::Stepper< Scalar >.

Definition at line 75 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ isOneStepMethod()

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

Implements Tempus::Stepper< Scalar >.

Definition at line 74 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ setInitialGuess()

template<class Scalar>
virtual void Tempus::StepperBackwardEuler< Scalar >::setInitialGuess ( Teuchos::RCP< const Thyra::VectorBase< Scalar > >  initial_guess)
inlinevirtual

Pass initial guess to Newton solver.

Reimplemented from Tempus::StepperImplicit< Scalar >.

Definition at line 61 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ setObserver()

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

Set Observer.

Implements Tempus::Stepper< Scalar >.

Definition at line 103 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ setParameterList()

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::setParameterList ( const Teuchos::RCP< Teuchos::ParameterList > &  pl)

Definition at line 274 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ setPredictor() [1/2]

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::setPredictor ( std::string  predictorName)

Set the predictor.

Set the predictor to a pre-defined predictor in the ParameterList. The predictor is set to predictorName sublist in the Stepper's ParameterList. The predictorName sublist should already be defined in the Stepper's ParameterList. Otherwise it will fail.

Definition at line 47 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ setPredictor() [2/2]

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::setPredictor ( Teuchos::RCP< Teuchos::ParameterList >  predPL = Teuchos::null)

Set the predictor to the supplied Parameter sublist. This adds a new predictor Parameter sublist to the Stepper's ParameterList. If the predictor sublist is null, it tests if the predictor is set in the Stepper's ParameterList.

Definition at line 66 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ stencilLength()

template<class Scalar >
int Tempus::StepperBackwardEuler< Scalar >::stencilLength ( ) const
virtual

Return the number of solution vectors in the time step stencil.

Implements Tempus::StepperOptimizationInterface< Scalar >.

Definition at line 358 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ takeStep()

template<class Scalar >
void Tempus::StepperBackwardEuler< 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 139 of file Tempus_StepperBackwardEuler_impl.hpp.

◆ unsetParameterList()

template<class Scalar >
Teuchos::RCP< Teuchos::ParameterList > Tempus::StepperBackwardEuler< Scalar >::unsetParameterList ( )

Definition at line 348 of file Tempus_StepperBackwardEuler_impl.hpp.

Member Data Documentation

◆ initial_guess_

template<class Scalar>
Teuchos::RCP<const Thyra::VectorBase<Scalar> > Tempus::StepperBackwardEuler< Scalar >::initial_guess_
private

Definition at line 153 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ predictorStepper_

template<class Scalar>
Teuchos::RCP<Stepper<Scalar> > Tempus::StepperBackwardEuler< Scalar >::predictorStepper_
private

Definition at line 148 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ stepperBEObserver_

template<class Scalar>
Teuchos::RCP<StepperBackwardEulerObserver<Scalar> > Tempus::StepperBackwardEuler< Scalar >::stepperBEObserver_
private

Definition at line 150 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ stepperObserver_

template<class Scalar>
Teuchos::RCP<StepperObserver<Scalar> > Tempus::StepperBackwardEuler< Scalar >::stepperObserver_
private

Definition at line 149 of file Tempus_StepperBackwardEuler_decl.hpp.

◆ xDotTemp_

template<class Scalar>
Teuchos::RCP<Thyra::VectorBase<Scalar> > Tempus::StepperBackwardEuler< Scalar >::xDotTemp_
mutableprivate

Definition at line 152 of file Tempus_StepperBackwardEuler_decl.hpp.


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