HeunIntegrator Class Reference

A simple predictor - corrector solver. More...

Inheritance diagram for HeunIntegrator:

Collaboration diagram for HeunIntegrator:

Detailed Description

A simple predictor - corrector solver.

Not tested and very experimentally \( y^{n+1} = y^n + \alpha f(y^n + f(y^n)dt)dt + (1-\alpha)f(y^n)dt \)

Public Member Functions
	HeunIntegrator (const cmf::math::state_list &states, real Alpha=0.5)
	Constructs a new PredictCorrectSimple from a pointer to a vector of state variables.
	HeunIntegrator (const Integrator &copy)
	copy constructor
	HeunIntegrator (real Alpha=0.5)
	Constructs a new Heun integrator.
virtual Integrator *	copy () const
	Polymorphic copy constructor.
int	integrate (cmf::math::Time MaxTime, cmf::math::Time TimeStep)
	Integrates the vector of state variables.
void	reset () override
	Resets any saved history (for multistep methods)
std::string	to_string () const override
	Desrcibes the iterator.
Integrate
void	integrate_until (cmf::math::Time t_max, cmf::math::Time dt=Time(), bool reset=false)
	Integrates the vector of state variables until t_max.

Public Attributes
real	alpha
	Alpha Weight factor \(\alpha\) to weight \(f(y^n)\) and \(f(y^{n+1})\).

Protected Attributes
Accuracy parameters
const real	Epsilon =1e-9
	Tolerable error.

model time
cmf::math::Time	get_t () const
	Returns the current model time.
void	set_t (cmf::math::Time val)
	Sets the current model time.
cmf::math::Time	get_dt () const
	Returns the last time step.
cmf::math::Time	m_t
	Actual time of the solver.
cmf::math::Time	m_dt
	last time step of the solver

Constructor & Destructor Documentation

HeunIntegrator() [1/2]

HeunIntegrator ( const cmf::math::state_list & states, real Alpha = 0.5 )

explicit

Constructs a new PredictCorrectSimple from a pointer to a vector of state variables.

Note

The Integrator becomes the owner of states

Parameters

states	Statevariable owner of the system
Alpha	Weight factor \(\alpha\) to weight \(f(y^n)\) and \(f(y^{n+1})\)

HeunIntegrator() [2/2]

HeunIntegrator

(

real

Alpha = 0.5

)

Constructs a new Heun integrator.

Parameters

Alpha

Weight factor \(\alpha\) to weight \(f(y^n)\) and \(f(y^{n+1})\)

Member Function Documentation

integrate()

int integrate ( cmf::math::Time MaxTime, cmf::math::Time TimeStep )

virtual

Integrates the vector of state variables.

Parameters

MaxTime	(ignored) To stop the model (if running in a model framework) at time steps of value exchange e.g. full hours, the next value exchange time can be given
TimeStep	Takes the proposed time step

Implements Integrator.

integrate_until()

void integrate_until ( cmf::math::Time t_max, cmf::math::Time dt = Time(), bool reset = false )

inherited

Integrates the vector of state variables until t_max.

Parameters

t_max	Time, the solver should run to
dt	Time step (may be omitted)
reset	If true, solver is reseted before integration starts