Package org.apache.commons.math.ode.events

Class EventState

  • public class EventState
extends java.lang.Object
    This class handles the state for one event handler during integration steps.

    Each time the integrator proposes a step, the event handler switching function should be checked. This class handles the state of one handler during one integration step, with references to the state at the end of the preceding step. This information is used to decide if the handler should trigger an event or not during the proposed step (and hence the step should be reduced to ensure the event occurs at a bound rather than inside the step).

    Since:
    1.2

    • Constructor Summary

      Constructors 
      Constructor Description
      EventState​(EventHandler handler, double maxCheckInterval, double convergence, int maxIterationCount)
      Simple constructor.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean evaluateStep​(StepInterpolator interpolator)
      Evaluate the impact of the proposed step on the event handler.
      double getConvergence()
      Get the convergence threshold for event localization.
      EventHandler getEventHandler()
      Get the underlying event handler.
      double getEventTime()
      Get the occurrence time of the event triggered in the current step.
      double getMaxCheckInterval()
      Get the maximal time interval between events handler checks.
      int getMaxIterationCount()
      Get the upper limit in the iteration count for event localization.
      void reinitializeBegin​(StepInterpolator interpolator)
      Reinitialize the beginning of the step.
      boolean reset​(double t, double[] y)
      Let the event handler reset the state if it wants.
      void stepAccepted​(double t, double[] y)
      Acknowledge the fact 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

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

    • Constructor Detail

      • EventState

        public EventState​(EventHandler handler,
                  double maxCheckInterval,
                  double convergence,
                  int maxIterationCount)
        Simple constructor.
        Parameters:
        handler - 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

    • Method Detail

      • getEventHandler

        public EventHandler getEventHandler()
        Get the underlying event handler.
        Returns:
        underlying event handler

      • getMaxCheckInterval

        public double getMaxCheckInterval()
        Get the maximal time interval between events handler checks.
        Returns:
        maximal time interval between events handler checks

      • getConvergence

        public double getConvergence()
        Get the convergence threshold for event localization.
        Returns:
        convergence threshold for event localization

      • getMaxIterationCount

        public int getMaxIterationCount()
        Get the upper limit in the iteration count for event localization.
        Returns:
        upper limit in the iteration count for event localization

      • reinitializeBegin

        public void reinitializeBegin​(StepInterpolator interpolator)
                       throws EventException
        Reinitialize the beginning of the step.
        Parameters:
        interpolator - valid for the current step
        Throws:
        EventException - if the event handler value cannot be evaluated at the beginning of the step

      • getEventTime

        public double getEventTime()
        Get the occurrence time of the event triggered in the current step.
        Returns:
        occurrence time of the event triggered in the current step or positive infinity if no events are triggered

      • stepAccepted

        public void stepAccepted​(double t,
                         double[] y)
                  throws EventException
        Acknowledge the fact the step has been accepted by the integrator.
        Parameters:
        t - value of the independent time variable at the end of the step
        y - array containing the current value of the state vector at the end of the step
        Throws:
        EventException - if the value of the event handler cannot be evaluated

      • 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 boolean reset​(double t,
                     double[] y)
              throws EventException
        Let the event handler reset the state if it wants.
        Parameters:
        t - value of the independent 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
        Returns:
        true if the integrator should reset the derivatives too
        Throws:
        EventException - if the state cannot be reseted by the event handler