TimeInterpolatorRK4 Class Reference

#include <TimeInterpolatorRK4.H>

Detailed Description

Time interpolator class using 4th-order Runge-Kutta.


Public Member Functions
	TimeInterpolatorRK4 ()
	Default constructor.
	~TimeInterpolatorRK4 ()
	Destructor.
void	define (const DisjointBoxLayout &a_thisDisjointBoxLayout, const DisjointBoxLayout &a_coarserDisjointBoxLayout, const ProblemDomain &a_domain, const int &a_refineCoarse, const int &a_numStates, const int &a_ghosts)
	Actual constructor.
void	setDt (const Real &a_dt)
	Set coarse timestep.
void	saveInitialSoln (const LevelData< FArrayBox > &a_soln)
	Update Taylor polynomial coefficients with the coarse solution.
void	saveRHS (const LevelData< FArrayBox > &a_rhs)
	Update Taylor polynomial coefficients with coarse right-hand side.
void	interpolate (LevelData< FArrayBox > &a_U, const Real &a_timeInterpCoeff, const Interval &a_intvl)
	Interpolate in time using the Taylor polynomial.
void	intermediate (LevelData< FArrayBox > &a_U, const Real &a_timeInterpCoeff, const int &a_stage, const Interval &a_intvl) const
	Set RK4 intermediate values in time using the Taylor polynomial.
Protected Member Functions
void	resetData ()
	Reset this object to use with new data.
void	setVectorDt (Vector< Real > &a_vec, Real a_c0, Real a_c1, Real a_c2, Real a_c3)
	Set a_vec = m_dt * (a_c0, a_c1, a_c2, a_c3).
Protected Attributes
Vector< Vector< Real > >	m_coeffs
DisjointBoxLayout	m_thisCoarsenedLayout
	layout for this level, coarsened by m_refToCoarse
DisjointBoxLayout	m_coarseLayout
	layout for the coarse level
Copier	m_copier
	For copying from rhs on m_coarseLayout to m_rhsCopy on m_thisCoarsenedLayout.
int	m_ghosts
	layers of ghost cells around m_thisCoarsenedLayout for m_rhsCopy and m_taylorCoeffs
int	m_numCoeffs
	number of coefficients in Taylor polynomial: this is 4
IntVect	m_ghostVect
	ghost vector around m_thisCoarsenedLayout for m_rhsCopy and m_taylorCoeffs
Real	m_dt
	coarse timestep
LevelData< FArrayBox >	m_rhsCopy
	Copy of rhs on m_thisCoarsenedLayout, to be used within saveRHS.
LevelData< FArrayBox >	m_taylorCoeffs
	coefficients of the third-degree Taylor polynomial on m_thisCoarsenedLayout with ghost vector m_ghostVect; m_numCoeffs*m_numStates components
LevelData< FArrayBox >	m_diff12
	difference between f(U1) and f(U2), used for intermediate-value calculations, on m_thisCoarsenedLayout with ghost vector m_ghostVect; m_numCoeffs*m_numStates components
bool	m_gotDt
	whether m_dt has been set
bool	m_gotInitialSoln
	whether initial solution has been saved
bool	m_gotFullTaylorPoly
	whether we have the full Taylor polynomial
int	m_countRHS
	number of times saveRHS function has been called
ProblemDomain	m_coarseDomain
	Problem domain - index space for next coarser level.
int	m_refineCoarse
	Refinement ratio between this level and the next coarser.
int	m_numStates
	Number of variables.
bool	m_defined
	define() has been called
Private Member Functions
void	operator= (const TimeInterpolatorRK4 &)
	TimeInterpolatorRK4 (const TimeInterpolatorRK4 &)

Constructor & Destructor Documentation

TimeInterpolatorRK4::TimeInterpolatorRK4 ( )

Default constructor.

Object requires define() to be called before all other functions.

TimeInterpolatorRK4::~TimeInterpolatorRK4 ( )

Destructor.

Destroys all objects created by define(). Passed in data references of define() are left alone.

TimeInterpolatorRK4::TimeInterpolatorRK4 ( const TimeInterpolatorRK4 & ) [private]

Member Function Documentation

void TimeInterpolatorRK4::define	(	const DisjointBoxLayout &	a_thisDisjointBoxLayout,
		const DisjointBoxLayout &	a_coarserDisjointBoxLayout,
		const ProblemDomain &	a_domain,
		const int &	a_refineCoarse,
		const int &	a_numStates,
		const int &	a_ghosts
	)

Actual constructor.

Set up object.

Parameters:

a_thisDisjointBoxLayout	layout at this level
a_coarserDisjointBoxLayout	layout at next coarser level
a_domain	problem domain on this level
a_refineCoarse	refinement ratio between this level and next coarser level
a_numStates	number of variables
a_ghosts	layers of ghost cells to be filled in on the coarsened layout at this level

void TimeInterpolatorRK4::setDt ( const Real & a_dt )

Set coarse timestep.

void TimeInterpolatorRK4::saveInitialSoln ( const LevelData< FArrayBox > & a_soln )

Update Taylor polynomial coefficients with the coarse solution.

Update Taylor polynomial coefficients with coarse solution a_soln. Ghost cells, too.

This function must be called after setDt() and before saveRHS().

void TimeInterpolatorRK4::saveRHS ( const LevelData< FArrayBox > & a_rhs )

Update Taylor polynomial coefficients with coarse right-hand side.

Update Taylor polynomial coefficients with coarse right-hand side. Ghost cells, too.

This function must be called exactly four times, after saveInitialSoln() and before any calls to interpolate().

The counter m_countRHS keeps track of how many times this is called.

void TimeInterpolatorRK4::interpolate	(	LevelData< FArrayBox > &	a_U,
		const Real &	a_timeInterpCoeff,
		const Interval &	a_intvl
	)

Interpolate in time using the Taylor polynomial.

Interpolate in time to a_U on interval a_intvl using the Taylor polynomial. Ghost cells, too.

Parameters:

a_U	interpolated solution on this level coarsened
a_timeInterpCoeff	time interpolation coefficient in range [0:1]
a_intvl	interval of a_U to fill in

void TimeInterpolatorRK4::intermediate	(	LevelData< FArrayBox > &	a_U,
		const Real &	a_timeInterpCoeff,
		const int &	a_stage,
		const Interval &	a_intvl
	)			const

Set RK4 intermediate values in time using the Taylor polynomial.

Set RK4 intermediate values to a_U on interval a_intvl using the Taylor polynomial. Ghost cells, too.

Parameters:

a_U	interpolated solution on this level coarsened
a_timeInterpCoeff	time interpolation coefficient in range [0:1]
a_stage	which RK4 stage: 0, 1, 2, 3
a_intvl	interval of a_U to fill in

void TimeInterpolatorRK4::resetData ( ) [protected]

Reset this object to use with new data.

void TimeInterpolatorRK4::setVectorDt	(	Vector< Real > &	a_vec,
		Real	a_c0,
		Real	a_c1,
		Real	a_c2,
		Real	a_c3
	)			`[protected]`

Set a_vec = m_dt * (a_c0, a_c1, a_c2, a_c3).

void TimeInterpolatorRK4::operator= ( const TimeInterpolatorRK4 & ) [private]

Member Data Documentation

Vector< Vector<Real> > TimeInterpolatorRK4::m_coeffs [protected]

DisjointBoxLayout TimeInterpolatorRK4::m_thisCoarsenedLayout [protected]

layout for this level, coarsened by m_refToCoarse

DisjointBoxLayout TimeInterpolatorRK4::m_coarseLayout [protected]

layout for the coarse level

Copier TimeInterpolatorRK4::m_copier [protected]

For copying from rhs on m_coarseLayout to m_rhsCopy on m_thisCoarsenedLayout.

int TimeInterpolatorRK4::m_ghosts [protected]

layers of ghost cells around m_thisCoarsenedLayout for m_rhsCopy and m_taylorCoeffs

int TimeInterpolatorRK4::m_numCoeffs [protected]

number of coefficients in Taylor polynomial: this is 4

IntVect TimeInterpolatorRK4::m_ghostVect [protected]

ghost vector around m_thisCoarsenedLayout for m_rhsCopy and m_taylorCoeffs

Real TimeInterpolatorRK4::m_dt [protected]

coarse timestep

LevelData<FArrayBox> TimeInterpolatorRK4::m_rhsCopy [protected]

Copy of rhs on m_thisCoarsenedLayout, to be used within saveRHS.

LevelData<FArrayBox> TimeInterpolatorRK4::m_taylorCoeffs [protected]

coefficients of the third-degree Taylor polynomial on m_thisCoarsenedLayout with ghost vector m_ghostVect; m_numCoeffs*m_numStates components

LevelData<FArrayBox> TimeInterpolatorRK4::m_diff12 [protected]

difference between f(U1) and f(U2), used for intermediate-value calculations, on m_thisCoarsenedLayout with ghost vector m_ghostVect; m_numCoeffs*m_numStates components

bool TimeInterpolatorRK4::m_gotDt [protected]

whether m_dt has been set

bool TimeInterpolatorRK4::m_gotInitialSoln [protected]

whether initial solution has been saved

bool TimeInterpolatorRK4::m_gotFullTaylorPoly [protected]

whether we have the full Taylor polynomial

int TimeInterpolatorRK4::m_countRHS [protected]

number of times saveRHS function has been called

ProblemDomain TimeInterpolatorRK4::m_coarseDomain [protected]

Problem domain - index space for next coarser level.

int TimeInterpolatorRK4::m_refineCoarse [protected]

Refinement ratio between this level and the next coarser.