org.jscience.mathematics.analysis.ode
Class SwitchingFunctionsHandler

java.lang.Object
  extended by org.jscience.mathematics.analysis.ode.SwitchingFunctionsHandler

public class SwitchingFunctionsHandler
extends java.lang.Object

This class handles several switching functions during integration.

See Also:
SwitchingFunction

Constructor Summary
SwitchingFunctionsHandler()
          Simple constructor.
 
Method Summary
 void add(SwitchingFunction function, double maxCheckInterval, double convergence)
          Add a switching function.
 boolean evaluateStep(StepInterpolator interpolator)
          Evaluate the impact of the proposed step on all handled switching functions.
 double getEventTime()
          Get the occurrence time of the first event triggered in the last evaluated step.
 boolean isEmpty()
          Check if the handler does not have any condition.
 void reset(double t, double[] y)
          Let the switching functions reset the state if they want.
 void stepAccepted(double t, double[] y)
          Inform the switching functions that the step has been accepted by the integrator.
 boolean stop()
          Check if the integration should be stopped at the end of the current step.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SwitchingFunctionsHandler

public SwitchingFunctionsHandler()
Simple constructor. Create an empty handler

Method Detail

add

public void add(SwitchingFunction function,
                double maxCheckInterval,
                double convergence)
Add a switching function.

Parameters:
function - switching function
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

isEmpty

public boolean isEmpty()
Check if the handler does not have any condition.

Returns:
true if handler is empty

evaluateStep

public boolean evaluateStep(StepInterpolator interpolator)
Evaluate the impact of the proposed step on all handled switching functions.

Parameters:
interpolator - step interpolator for the proposed step
Returns:
true if at least one switching function triggers an event before the end of the proposed step (this implies the step should be rejected)

getEventTime

public double getEventTime()
Get the occurrence time of the first event triggered in the last evaluated step.

Returns:
occurrence time of the first event triggered in the last evaluated step, or Double.NaN if no event is triggered

stepAccepted

public void stepAccepted(double t,
                         double[] y)
Inform the switching functions that the step has been accepted by the integrator.

Parameters:
t - value of the independant time variable at the end of the step
y - array containing the current value of the state vector at the end of the step

stop

public boolean stop()
Check if the integration should be stopped at the end of the current step.

Returns:
true if the integration should be stopped

reset

public void reset(double t,
                  double[] y)
Let the switching functions reset the state if they want.

Parameters:
t - value of the independant time variable at the beginning of the next step
y - array were to put the desired state vector at the beginning of the next step