RungeKuttaFehlbergIvpOdeSolver Class Reference

#include <RungeKuttaFehlbergIvpOdeSolver.hpp>

Inheritance diagram for RungeKuttaFehlbergIvpOdeSolver:

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Collaboration diagram for RungeKuttaFehlbergIvpOdeSolver:

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List of all members.

Public Member Functions
OdeSolution	Solve (AbstractOdeSystem *pAbstractOdeSystem, std::vector< double > &rYValues, double startTime, double endTime, double timeStep, double ignoredSamplingTime)
void	Solve (AbstractOdeSystem *pAbstractOdeSystem, std::vector< double > &rYValues, double startTime, double endTime, double timeStep)
Protected Member Functions
void	InternalSolve (OdeSolution &rSolution, AbstractOdeSystem *pAbstractOdeSystem, std::vector< double > &rCurrentYValues, std::vector< double > &rWorkingMemory, double startTime, double endTime, double maxTimeStep, double minTimeStep, double tolerance, bool outputSolution)
void	CalculateNextYValue (AbstractOdeSystem *pAbstractOdeSystem, double timeStep, double time, std::vector< double > &currentYValues, std::vector< double > &nextYValues)
void	AdjustStepSize (double &rCurrentStepSize, const double &rError, const double &rTolerance, const double &rMaxTimeStep, const double &rMinTimeStep)
Private Attributes
double	m1932o2197
double	m7200o2197
double	m7296o2197
double	m12o13
double	m439o216
double	m3680o513
double	m845o4104
double	m8o27
double	m3544o2565
double	m1859o4104
double	m1o360
double	m128o4275
double	m2197o75240
double	m2o55
double	m25o216
double	m1408o2565
double	m2197o4104
std::vector< double >	mError
std::vector< double >	mk1
std::vector< double >	mk2
std::vector< double >	mk3
std::vector< double >	mk4
std::vector< double >	mk5
std::vector< double >	mk6
std::vector< double >	myk2
std::vector< double >	myk3
std::vector< double >	myk4
std::vector< double >	myk5
std::vector< double >	myk6
Friends
class	TestRungeKuttaFehlbergIvpOdeSolver

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Detailed Description

Concrete RungeKuttaFehlbergIvpOdeSolver class. Use this class to solve a system of ODEs using the Runge Kutta Fehlberg Adaptive timestep Initial Value Problem Ordinary Differential Equation Solver (RKF45).

Good for problems where you need to be able to guarantee the accuracy of the answer as it is specified via the tolerance parameter.

Should be reasonably fast too as it increases the timestep when the solutions are changing slowly, whilst maintaining accuracy.

Definition at line 53 of file RungeKuttaFehlbergIvpOdeSolver.hpp.

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Member Function Documentation

void RungeKuttaFehlbergIvpOdeSolver::InternalSolve	(	OdeSolution &	rSolution,
		AbstractOdeSystem *	pAbstractOdeSystem,
		std::vector< double > &	rCurrentYValues,
		std::vector< double > &	rWorkingMemory,
		double	startTime,
		double	endTime,
		double	maxTimeStep,
		double	minTimeStep,
		double	tolerance,
		bool	outputSolution
	)			[protected]

Method that actually performs the solving on behalf of the public Solve methods.

Parameters:

	rSolution	an ode solution to input data into if requited
	pAbstractOdeSystem	the system to solve
	rCurrentYValues	the current (initial) state; results will also be returned in here
	rWorkingMemory	working memory; same size as rCurrentYValues
	startTime	initial time
	endTime	time to solve to
	timeStep	dt
	outputSolution	whether to output into rSolution (or save time by not doing)

Definition at line 49 of file RungeKuttaFehlbergIvpOdeSolver.cpp.

References AdjustStepSize(), CalculateNextYValue(), AbstractOdeSystem::CalculateStoppingEvent(), AbstractOdeSystem::GetNumberOfStateVariables(), AbstractIvpOdeSolver::mStoppingEventOccurred, AbstractIvpOdeSolver::mStoppingTime, OdeSolution::rGetSolutions(), OdeSolution::rGetTimes(), and OdeSolution::SetNumberOfTimeSteps().

Referenced by Solve().

void RungeKuttaFehlbergIvpOdeSolver::CalculateNextYValue	(	AbstractOdeSystem *	pAbstractOdeSystem,
		double	timeStep,
		double	time,
		std::vector< double > &	currentYValues,
		std::vector< double > &	nextYValues
	)			[protected]

Calculate the next time step, using rkf45 numerical routine

Updates the mError vector with current error.

Parameters:

	pAbstractOdeSystem	the ode system to be solved
	timeStep	the current timestep
	time	the current time
	currentYValues	Y Values at the current time
	nextYValues	the 4th order approximation for the Y values at the end of the timestep.

Definition at line 163 of file RungeKuttaFehlbergIvpOdeSolver.cpp.

References AbstractOdeSystem::EvaluateYDerivatives(), and AbstractOdeSystem::GetNumberOfStateVariables().

Referenced by InternalSolve().

void RungeKuttaFehlbergIvpOdeSolver::AdjustStepSize	(	double &	rCurrentStepSize,
		const double &	rError,
		const double &	rTolerance,
		const double &	rMaxTimeStep,
		const double &	rMinTimeStep
	)			[protected]

Uses the error approximation of the last CalculateNextYValue() call to change the time step appropriately.

Parameters:

	rCurrentStepSize	The current step size being used (returns answer via this reference)
	rError	The error in the approximation at this time step
	rTolerance	The tolerance required
	rMaxTimeStep	The maximum timestep to be used
	rMinTimeStep	The minimum timestep to be used (to prevent huge loops)

Definition at line 224 of file RungeKuttaFehlbergIvpOdeSolver.cpp.

Referenced by InternalSolve().

OdeSolution RungeKuttaFehlbergIvpOdeSolver::Solve	(	AbstractOdeSystem *	pAbstractOdeSystem,
		std::vector< double > &	rYValues,
		double	startTime,
		double	endTime,
		double	timeStep,
		double	timeSampling
	)			[virtual]

Solves a system of ODEs using a specified one-step ODE solver

Parameters:

	pAbstractOdeSystem	points to the concrete ODE system to be solved
	startTime	the time at which the initial conditions are specified
	endTime	the time to which the system should be solved and the solution returned
	timeStep	the time interval to be used by the solver
	initialConditions	a standard vector specifying the intial condition of each solution variable in the system.

Returns:

OdeSolution is an object containing an integer of the number of equations, a stdAbstractOdeSystem::vector of times and a std::vector of std::vectors where each of those vectors contains the solution for one variable of the ODE system at those times.

Implements AbstractIvpOdeSolver.

Definition at line 267 of file RungeKuttaFehlbergIvpOdeSolver.cpp.

References AbstractOdeSystem::CalculateStoppingEvent(), AbstractOdeSystem::GetNumberOfStateVariables(), InternalSolve(), and AbstractIvpOdeSolver::mStoppingEventOccurred.

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

• /tmp/release_1/ode/src/solver/RungeKuttaFehlbergIvpOdeSolver.hpp
• /tmp/release_1/ode/src/solver/RungeKuttaFehlbergIvpOdeSolver.cpp