TimeStepper Class Reference

#include <TimeStepper.hpp>

Collaboration diagram for TimeStepper:

Public Member Functions
	TimeStepper (double startTime, double endTime, double dt, bool enforceConstantTimeStep=false, std::vector< double > additionalTimes=std::vector< double >())
void	AdvanceOneTimeStep ()
double	GetTime () const
double	GetNextTime () const
double	GetNextTimeStep ()
double	GetIdealTimeStep ()
bool	IsTimeAtEnd () const
unsigned	EstimateTimeSteps () const
unsigned	GetTotalTimeStepsTaken () const
void	ResetTimeStep (double dt)
Private Member Functions
double	CalculateNextTime ()
template<class Archive >
void	serialize (Archive &archive, const unsigned int version)
Private Attributes
double	mStart
double	mEnd
double	mDt
unsigned	mTotalTimeStepsTaken
unsigned	mAdditionalTimesReached
double	mTime
double	mNextTime
double	mEpsilon
std::vector< double >	mAdditionalTimes
Friends
class	TestTimeStepper
class	boost::serialization::access

Detailed Description

A helper class that provides a robust way to deal with time loops.

An incremented integer counter is used to calculate the current time and ensure that the correct end time.

Definition at line 45 of file TimeStepper.hpp.

Constructor & Destructor Documentation

TimeStepper::TimeStepper	(	double	startTime,
		double	endTime,
		double	dt,
		bool	enforceConstantTimeStep = `false`,
		std::vector< double >	additionalTimes = `std::vector<double> ()`
	)

Create a new time stepper over some simulation interval. Time units are not specified, but all parameters should have consistent units.

Parameters:

	startTime	the start of the interval
	endTime	the end of the interval
	dt	the time step to use.
	enforceConstantTimeStep	If this is true the stepper estimates whether non-constant timesteps will be used and quits if so.
	additionalTimes	If the timestepper needs to stop at certain additional times, they can be passed in in this std::vector. Defaults to empty. These times must be in ascending order. Note that if, for example, start=0, end=0.5, dt=0.1, and the additional stopping time is 0.33, the times used will be 0,0.1,0.2,0.3,0.33,0.4,0.5 NOT ..,0.33,0.43,0.5

Definition at line 36 of file TimeStepper.cpp.

References CalculateNextTime(), EstimateTimeSteps(), EXCEPTION, mAdditionalTimes, mDt, mEnd, mEpsilon, mNextTime, and mStart.

Member Function Documentation

void TimeStepper::AdvanceOneTimeStep ( )

Step forward one step in time and update member variables.

Note that this should be used in conjuction with (not) IsTimeAtEnd because increment past the end of a simulation will throw an exception

Definition at line 127 of file TimeStepper.cpp.

References CalculateNextTime(), EXCEPTION, mNextTime, mTime, and mTotalTimeStepsTaken.

Referenced by AbstractRushLarsenCardiacCell::ComputeExceptVoltage(), AbstractOneStepIvpOdeSolver::InternalSolve(), NhsModelWithBackwardSolver::RunDoNotUpdate(), AbstractDynamicLinearPdeSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve(), CvodeAdaptor::Solve(), AbstractOneStepIvpOdeSolver::Solve(), AbstractCvodeSystem::Solve(), AdaptiveBidomainProblem::Solve(), AbstractCardiacProblem< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve(), AbstractRushLarsenCardiacCell::SolveAndUpdateState(), AbstractBackwardEulerCardiacCell< SIZE >::SolveAndUpdateState(), and LinearParabolicPdeSystemWithCoupledOdeSystemSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::SolveAndWriteResultsToFile().

double TimeStepper::CalculateNextTime ( ) [private]

Compute what the time will be after the next time step.

Definition at line 98 of file TimeStepper.cpp.

References mAdditionalTimes, mAdditionalTimesReached, mDt, mEnd, mEpsilon, mStart, and mTotalTimeStepsTaken.

Referenced by AdvanceOneTimeStep(), ResetTimeStep(), and TimeStepper().

unsigned TimeStepper::EstimateTimeSteps ( ) const

Estimate number of time steps remaining, which may be an overestimate. Used to reserve memory for writing intermediate solutions.

Definition at line 184 of file TimeStepper.cpp.

References mAdditionalTimes, mDt, mEnd, and mStart.

Referenced by AbstractCardiacProblem< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::DefineWriterColumns(), CvodeAdaptor::Solve(), AbstractOneStepIvpOdeSolver::Solve(), AbstractCvodeSystem::Solve(), and TimeStepper().

double TimeStepper::GetIdealTimeStep ( )

Get the size of the ideal time step (as set in the constructor. Note when a fixed time step is used GetNextTimeStep() == GetIdealTimeStep() until the end of the simulation when GetNextTimeStep() == 0.0

Definition at line 174 of file TimeStepper.cpp.

References mDt.

double TimeStepper::GetNextTime ( ) const

Get the value time will take at the next step.

Definition at line 148 of file TimeStepper.cpp.

References mNextTime.

Referenced by CvodeAdaptor::Solve(), AbstractOneStepIvpOdeSolver::Solve(), AbstractCvodeSystem::Solve(), AdaptiveBidomainProblem::Solve(), AbstractCardiacProblem< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve(), and LinearParabolicPdeSystemWithCoupledOdeSystemSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::SolveAndWriteResultsToFile().

double TimeStepper::GetNextTimeStep ( )

Get the size of the next time step which will be taken. GetNextTimeStep() == GetNextTime() - GetTime()

Definition at line 153 of file TimeStepper.cpp.

References mAdditionalTimes, mAdditionalTimesReached, mDt, mEnd, mNextTime, and mTime.

Referenced by AbstractOneStepIvpOdeSolver::InternalSolve(), and AbstractDynamicLinearPdeSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve().

double TimeStepper::GetTime ( ) const

Get the time.

Definition at line 143 of file TimeStepper.cpp.

References mTime.

Referenced by AbstractRushLarsenCardiacCell::ComputeExceptVoltage(), AbstractOneStepIvpOdeSolver::InternalSolve(), AbstractDynamicLinearPdeSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve(), AbstractOneStepIvpOdeSolver::Solve(), AdaptiveBidomainProblem::Solve(), AbstractCardiacProblem< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve(), AbstractRushLarsenCardiacCell::SolveAndUpdateState(), AbstractBackwardEulerCardiacCell< SIZE >::SolveAndUpdateState(), and LinearParabolicPdeSystemWithCoupledOdeSystemSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::SolveAndWriteResultsToFile().

unsigned TimeStepper::GetTotalTimeStepsTaken ( ) const

The number of times AdvanceOneTimeStep() has been called SINCE the last time ResetTimeStep() was called.

Definition at line 189 of file TimeStepper.cpp.

References mTotalTimeStepsTaken.

Referenced by AbstractDynamicLinearPdeSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve(), CvodeAdaptor::Solve(), AbstractOneStepIvpOdeSolver::Solve(), AbstractCvodeSystem::Solve(), and LinearParabolicPdeSystemWithCoupledOdeSystemSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::SolveAndWriteResultsToFile().

bool TimeStepper::IsTimeAtEnd ( ) const

True when GetTime == endTime.

Definition at line 179 of file TimeStepper.cpp.

References mEnd, and mTime.

Referenced by AbstractRushLarsenCardiacCell::ComputeExceptVoltage(), AbstractOneStepIvpOdeSolver::InternalSolve(), NhsModelWithBackwardSolver::RunDoNotUpdate(), AbstractDynamicLinearPdeSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve(), CvodeAdaptor::Solve(), AbstractOneStepIvpOdeSolver::Solve(), AbstractCvodeSystem::Solve(), AdaptiveBidomainProblem::Solve(), AbstractCardiacProblem< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve(), AbstractRushLarsenCardiacCell::SolveAndUpdateState(), AbstractBackwardEulerCardiacCell< SIZE >::SolveAndUpdateState(), and LinearParabolicPdeSystemWithCoupledOdeSystemSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::SolveAndWriteResultsToFile().

void TimeStepper::ResetTimeStep ( double dt )

Set the time step to use for adaptive time integration. Note that this also resets mStart to be the current time and zeroes mTotalTimeStepsTaken.

Parameters:

dt

is the new time-step

Definition at line 194 of file TimeStepper.cpp.

References CalculateNextTime(), mDt, mNextTime, mStart, mTime, and mTotalTimeStepsTaken.

Referenced by AbstractDynamicLinearPdeSolver< ELEMENT_DIM, SPACE_DIM, PROBLEM_DIM >::Solve().

template<class Archive >

void TimeStepper::serialize	(	Archive &	archive,
		const unsigned int	version
	)			`[inline, private]`

Parameters:

	archive	the archive
	version	the current version of this class

Definition at line 173 of file TimeStepper.hpp.

References mAdditionalTimes, mAdditionalTimesReached, mDt, mEnd, mEpsilon, mNextTime, mStart, mTime, and mTotalTimeStepsTaken.

Friends And Related Function Documentation

friend class boost::serialization::access [friend]

Needed for serialization.

Definition at line 165 of file TimeStepper.hpp.

Member Data Documentation

std::vector<double> TimeStepper::mAdditionalTimes [private]

Vector to store the additional times the stepper must stop at.

Definition at line 162 of file TimeStepper.hpp.

Referenced by CalculateNextTime(), EstimateTimeSteps(), GetNextTimeStep(), serialize(), and TimeStepper().

unsigned TimeStepper::mAdditionalTimesReached [private]

The number of times one of the 'additional times' has been passed.

Definition at line 143 of file TimeStepper.hpp.

Referenced by CalculateNextTime(), GetNextTimeStep(), and serialize().

double TimeStepper::mDt [private]

The size of time step.

Definition at line 137 of file TimeStepper.hpp.

Referenced by CalculateNextTime(), EstimateTimeSteps(), GetIdealTimeStep(), GetNextTimeStep(), ResetTimeStep(), serialize(), and TimeStepper().

double TimeStepper::mEnd [private]

The end time.

Definition at line 134 of file TimeStepper.hpp.

Referenced by CalculateNextTime(), EstimateTimeSteps(), GetNextTimeStep(), IsTimeAtEnd(), serialize(), and TimeStepper().

double TimeStepper::mEpsilon [private]

An architecture-dependent scaling factor. This is so that we can compare relative to the end time when mEnd is large. mEpsilon = DBL_EPSILON when mEnd is small = mEnd*DBL_EPSILON when mEnd is large

Definition at line 156 of file TimeStepper.hpp.

Referenced by CalculateNextTime(), serialize(), and TimeStepper().

double TimeStepper::mNextTime [private]

What the time will be after the next time step.

Definition at line 149 of file TimeStepper.hpp.

Referenced by AdvanceOneTimeStep(), GetNextTime(), GetNextTimeStep(), ResetTimeStep(), serialize(), and TimeStepper().