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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 ()
 Default constructor. More...
 
 StepperBackwardEuler (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...
 
virtual void computePredictor (const Teuchos::RCP< SolutionHistory< Scalar > > &solutionHistory)
 Compute predictor given the supplied stepper. More...
 
Teuchos::RCP< const
Teuchos::ParameterList > 		getValidParameters () 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...
 
void setPredictor (std::string predictorType="None")
 Set the predictor. More...
 
void setPredictor (Teuchos::RCP< Stepper< Scalar > > predictorStepper)
 Set the predictor. 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
 
Implementation of StepperOptimizationInterface
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...
 
- 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
 
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 std::string description () const
 
virtual void createSubSteppers (std::vector< Teuchos::RCP< const Thyra::ModelEvaluator< Scalar > > >)
 
- Public Member Functions inherited from Tempus::StepperOptimizationInterface< Scalar >
 StepperOptimizationInterface ()
 
virtual ~StepperOptimizationInterface ()
 

Private Member Functions

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...
 

Private Attributes

Teuchos::RCP< Stepper< Scalar > > predictorStepper_
 
Teuchos::RCP
< StepperBackwardEulerObserver
< Scalar > > 		stepperBEObserver_
 

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::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 $x_n$
  • $\dot{x}_n \leftarrow (x_n-x_{n-1})/\Delta t_n$

The First-Step-As-Last (FSAL) principle is not needed with Backward Euler. The default is to set useFSAL=false, however useFSAL=true will also work but have no affect (i.e., no-op).

Definition at line 36 of file Tempus_StepperBackwardEuler_decl.hpp.

Constructor & Destructor Documentation

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

Default constructor.

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

Definition at line 26 of file Tempus_StepperBackwardEuler_impl.hpp.

template<class Scalar >
Tempus::StepperBackwardEuler< Scalar >::StepperBackwardEuler ( 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_StepperBackwardEuler_impl.hpp.

Member Function Documentation

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.

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 306 of file Tempus_StepperBackwardEuler_impl.hpp.

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 323 of file Tempus_StepperBackwardEuler_impl.hpp.

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 356 of file Tempus_StepperBackwardEuler_impl.hpp.

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 291 of file Tempus_StepperBackwardEuler_impl.hpp.

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 340 of file Tempus_StepperBackwardEuler_impl.hpp.

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

Definition at line 256 of file Tempus_StepperBackwardEuler_impl.hpp.

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

Return alpha = d(xDot)/dx.

Implements Tempus::StepperImplicit< Scalar >.

Definition at line 99 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Return beta = d(x)/dx.

Implements Tempus::StepperImplicit< Scalar >.

Definition at line 101 of file Tempus_StepperBackwardEuler_decl.hpp.

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.

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

Get Observer.

Implements Tempus::Stepper< Scalar >.

Definition at line 64 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 84 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 86 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 85 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 95 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 267 of file Tempus_StepperBackwardEuler_impl.hpp.

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

Initialize during construction and after changing input parameters.

Implements Tempus::Stepper< Scalar >.

Definition at line 125 of file Tempus_StepperBackwardEuler_impl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 88 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 90 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 89 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 93 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Implements Tempus::Stepper< Scalar >.

Definition at line 92 of file Tempus_StepperBackwardEuler_decl.hpp.

template<class Scalar >
void Tempus::StepperBackwardEuler< 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 135 of file Tempus_StepperBackwardEuler_impl.hpp.

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 104 of file Tempus_StepperBackwardEuler_impl.hpp.

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::setPredictor ( std::string  predictorType = "None")

Set the predictor.

Set the predictor to a Stepper with default settings.

Definition at line 68 of file Tempus_StepperBackwardEuler_impl.hpp.

template<class Scalar >
void Tempus::StepperBackwardEuler< Scalar >::setPredictor ( Teuchos::RCP< Stepper< Scalar > >  predictorStepper)

Set the predictor.

Definition at line 89 of file Tempus_StepperBackwardEuler_impl.hpp.

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 283 of file Tempus_StepperBackwardEuler_impl.hpp.

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 160 of file Tempus_StepperBackwardEuler_impl.hpp.

Member Data Documentation

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

Definition at line 158 of file Tempus_StepperBackwardEuler_decl.hpp.

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

Definition at line 159 of file Tempus_StepperBackwardEuler_decl.hpp.

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