Time-derivative interface for BDF2. More...

#include <Tempus_StepperBDF2_decl.hpp>

Inheritance diagram for Tempus::StepperBDF2TimeDerivative< Scalar >:

Public Member Functions
	StepperBDF2TimeDerivative (Scalar dt, Scalar dtOld, Teuchos::RCP< const Thyra::VectorBase< Scalar > > xOld, Teuchos::RCP< const Thyra::VectorBase< Scalar > > xOldOld)
	Constructor. More...

virtual	~StepperBDF2TimeDerivative ()
	Destructor. More...

virtual void	compute (Teuchos::RCP< const Thyra::VectorBase< Scalar > > x, Teuchos::RCP< Thyra::VectorBase< Scalar > > xDot, Teuchos::RCP< Thyra::VectorBase< Scalar > > xDotDot=Teuchos::null)
	Compute the time derivative. More...

virtual void	initialize (Scalar dt, Scalar dtOld, Teuchos::RCP< const Thyra::VectorBase< Scalar > > xOld, Teuchos::RCP< const Thyra::VectorBase< Scalar > > xOldOld)

Private Attributes
Teuchos::RCP< const Thyra::VectorBase< Scalar > >	xOld_

Teuchos::RCP< const Thyra::VectorBase< Scalar > >	xOldOld_

Scalar	dt_

Scalar	dtOld_

Detailed Description

template<typename Scalar>
class Tempus::StepperBDF2TimeDerivative< Scalar >

Time-derivative interface for BDF2.

Given the state $x$ , compute the BDF2 time-derivative,

$\dot{x}_{n} = \frac{x_{n-1}-x_{n-2}}{\tau_{n-1}} + \left(\frac{1}{\tau_{n-1}-\tau_n} \right) \left(\frac{x_n-x_{n-1}}{\tau_{n-1} + \tau_n} - \frac{x_{n-1}-x_{n-2}}{\tau_{n-1}}\right) (2\tau_n + \tau_{n-1})$

where

$\tau_n = t_n - t_{n-1}.$

$\ddot{x}$ is not used and set to null.

Definition at line 146 of file Tempus_StepperBDF2_decl.hpp.

Constructor & Destructor Documentation

◆ StepperBDF2TimeDerivative()

template<typename Scalar >

Tempus::StepperBDF2TimeDerivative< Scalar >::StepperBDF2TimeDerivative	(	Scalar	dt,
		Scalar	dtOld,
		Teuchos::RCP< const Thyra::VectorBase< Scalar > >	xOld,
		Teuchos::RCP< const Thyra::VectorBase< Scalar > >	xOldOld
	)

inline

Constructor.

Definition at line 152 of file Tempus_StepperBDF2_decl.hpp.

◆ ~StepperBDF2TimeDerivative()

template<typename Scalar >

virtual Tempus::StepperBDF2TimeDerivative< Scalar >::~StepperBDF2TimeDerivative ( )

inlinevirtual

Destructor.

Definition at line 158 of file Tempus_StepperBDF2_decl.hpp.

Member Function Documentation

◆ compute()

template<typename Scalar >

virtual void Tempus::StepperBDF2TimeDerivative< Scalar >::compute	(	Teuchos::RCP< const Thyra::VectorBase< Scalar > >	x,
		Teuchos::RCP< Thyra::VectorBase< Scalar > >	xDot,
		Teuchos::RCP< Thyra::VectorBase< Scalar > >	xDotDot = `Teuchos::null`
	)

inlinevirtual

Compute the time derivative.

Implements Tempus::TimeDerivative< Scalar >.

Definition at line 161 of file Tempus_StepperBDF2_decl.hpp.

◆ initialize()

template<typename Scalar >

virtual void Tempus::StepperBDF2TimeDerivative< Scalar >::initialize	(	Scalar	dt,
		Scalar	dtOld,
		Teuchos::RCP< const Thyra::VectorBase< Scalar > >	xOld,
		Teuchos::RCP< const Thyra::VectorBase< Scalar > >	xOldOld
	)