org.apache.commons.math.ode
Class AbstractIntegrator

java.lang.Object
  org.apache.commons.math.ode.AbstractIntegrator

All Implemented Interfaces:

Serializable, FirstOrderIntegrator, ODEIntegrator

Direct Known Subclasses:

AdaptiveStepsizeIntegrator, MultistepIntegrator, RungeKuttaIntegrator

public abstract class AbstractIntegrator
extends Object
implements FirstOrderIntegrator

Base class managing common boilerplate for all integrators.

Since:

2.0

Version:

$Revision$ $Date$

See Also:

Serialized Form

Field Summary

protected CombinedEventsManager	eventsHandlersManager Events handlers manager.
protected Collection<StepHandler>	stepHandlers Step handler.
protected double	stepSize Current stepsize.
protected double	stepStart Current step start time.

Constructor Summary

AbstractIntegrator(String name)
Build an instance.

Method Summary

protected CombinedEventsManager	addEndTimeChecker(double startTime, double endTime, CombinedEventsManager manager) Add an event handler for end time checking.
void	addEventHandler(EventHandler function, double maxCheckInterval, double convergence, int maxIterationCount) Add an event handler to the integrator.
void	addStepHandler(StepHandler handler) Add a step handler to this integrator.
void	clearEventHandlers() Remove all the event handlers that have been added to the integrator.
void	clearStepHandlers() Remove all the step handlers that have been added to the integrator.
double	getCurrentSignedStepsize() Get the current signed value of the integration stepsize.
double	getCurrentStepStart() Get the current value of the step start time ti.
Collection<EventHandler>	getEventHandlers() Get all the event handlers that have been added to the integrator.
String	getName() Get the name of the method.
Collection<StepHandler>	getStepHandlers() Get all the step handlers that have been added to the integrator.
protected boolean	requiresDenseOutput() Check if one of the step handlers requires dense output.
protected void	sanityChecks(FirstOrderDifferentialEquations equations, double t0, double[] y0, double t, double[] y) Perform some sanity checks on the integration parameters.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.commons.math.ode.FirstOrderIntegrator

integrate

Field Detail

stepHandlers

protected Collection<StepHandler> stepHandlers

Step handler.

stepStart

protected double stepStart

Current step start time.

stepSize

protected double stepSize

Current stepsize.

eventsHandlersManager

protected CombinedEventsManager eventsHandlersManager

Events handlers manager.

Constructor Detail

AbstractIntegrator

public AbstractIntegrator(String name)

Build an instance.

Parameters:

name - name of the method

Method Detail

getName

public String getName()

Get the name of the method.

Specified by:

getName in interface ODEIntegrator

Returns:

name of the method

addStepHandler

public void addStepHandler(StepHandler handler)

Add a step handler to this integrator.

The handler will be called by the integrator for each accepted step.

Specified by:

addStepHandler in interface ODEIntegrator

Parameters:

handler - handler for the accepted steps

See Also:

ODEIntegrator.getStepHandlers(), ODEIntegrator.clearStepHandlers()

getStepHandlers

public Collection<StepHandler> getStepHandlers()

Get all the step handlers that have been added to the integrator.

Specified by:

getStepHandlers in interface ODEIntegrator

Returns:

an unmodifiable collection of the added events handlers

See Also:

ODEIntegrator.addStepHandler(StepHandler), ODEIntegrator.clearStepHandlers()

clearStepHandlers

public void clearStepHandlers()

Remove all the step handlers that have been added to the integrator.

Specified by:

clearStepHandlers in interface ODEIntegrator

See Also:

ODEIntegrator.addStepHandler(StepHandler), ODEIntegrator.getStepHandlers()

addEventHandler

public void addEventHandler(EventHandler function,
                            double maxCheckInterval,
                            double convergence,
                            int maxIterationCount)

Add an event handler to the integrator.

Specified by:

addEventHandler in interface ODEIntegrator

Parameters:

function - event handler

maxCheckInterval - maximal time interval between switching function checks (this interval prevents missing sign changes in case the integration steps becomes very large)

convergence - convergence threshold in the event time search

maxIterationCount - upper limit of the iteration count in the event time search

See Also:

ODEIntegrator.getEventHandlers(), ODEIntegrator.clearEventHandlers()

getEventHandlers

public Collection<EventHandler> getEventHandlers()

Get all the event handlers that have been added to the integrator.

Specified by:

getEventHandlers in interface ODEIntegrator

Returns:

an unmodifiable collection of the added events handlers

See Also:

ODEIntegrator.addEventHandler(EventHandler, double, double, int), ODEIntegrator.clearEventHandlers()

clearEventHandlers

public void clearEventHandlers()

Remove all the event handlers that have been added to the integrator.

Specified by:

clearEventHandlers in interface ODEIntegrator

See Also:

ODEIntegrator.addEventHandler(EventHandler, double, double, int), ODEIntegrator.getEventHandlers()

requiresDenseOutput

protected boolean requiresDenseOutput()

Check if one of the step handlers requires dense output.

Returns:

true if one of the step handlers requires dense output

getCurrentStepStart

public double getCurrentStepStart()

Get the current value of the step start time t_i.

This method can be called during integration (typically by the object implementing the differential equations problem) if the value of the current step that is attempted is needed.

The result is undefined if the method is called outside of calls to #integrate

Specified by:

getCurrentStepStart in interface ODEIntegrator

Returns:

current value of the step start time t_i

getCurrentSignedStepsize

public double getCurrentSignedStepsize()

Get the current signed value of the integration stepsize.

This method can be called during integration (typically by the object implementing the differential equations problem) if the signed value of the current stepsize that is tried is needed.

The result is undefined if the method is called outside of calls to #integrate

Specified by:

getCurrentSignedStepsize in interface ODEIntegrator

Returns:

current signed value of the stepsize

sanityChecks

protected void sanityChecks(FirstOrderDifferentialEquations equations,
                            double t0,
                            double[] y0,
                            double t,
                            double[] y)
                     throws IntegratorException

Perform some sanity checks on the integration parameters.

Parameters:

equations - differential equations set

t0 - start time

y0 - state vector at t0

t - target time for the integration

y - placeholder where to put the state vector

Throws:

IntegratorException - if some inconsistency is detected

addEndTimeChecker

protected CombinedEventsManager addEndTimeChecker(double startTime,
                                                  double endTime,
                                                  CombinedEventsManager manager)

Add an event handler for end time checking.

This method can be used to simplify handling of integration end time. It leverages the nominal stop condition with the exceptional stop conditions.

Parameters:

startTime - integration start time

endTime - desired end time

manager - manager containing the user-defined handlers

Returns:

a new manager containing all the user-defined handlers plus a dedicated manager triggering a stop event at entTime