Class EventState

java.lang.Object
org.apache.commons.math3.ode.events.EventState
public class EventState extends 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.

Since:
1.2

  • Field Details

    • handler

      private final EventHandler handler
      Event handler.

    • maxCheckInterval

      private final double maxCheckInterval
      Maximal time interval between events handler checks.

    • convergence

      private final double convergence
      Convergence threshold for event localization.

    • maxIterationCount

      private final int maxIterationCount
      Upper limit in the iteration count for event localization.

    • expandable

      private ExpandableStatefulODE expandable
      Equation being integrated.

    • t0

      private double t0
      Time at the beginning of the step.

    • g0

      private double g0
      Value of the events handler at the beginning of the step.

    • g0Positive

      private boolean g0Positive
      Simulated sign of g0 (we cheat when crossing events).

    • pendingEvent

      private boolean pendingEvent
      Indicator of event expected during the step.

    • pendingEventTime

      private double pendingEventTime
      Occurrence time of the pending event.

    • previousEventTime

      private double previousEventTime
      Occurrence time of the previous event.

    • forward

      private boolean forward
      Integration direction.

    • increasing

      private boolean increasing
      Variation direction around pending event. (this is considered with respect to the integration direction)

    • nextAction

      private EventHandler.Action nextAction
      Next action indicator.

    • solver

      private final UnivariateSolver solver
      Root-finding algorithm to use to detect state events.

  • Constructor Details

    • EventState

      public EventState(EventHandler handler, double maxCheckInterval, double convergence, int maxIterationCount, UnivariateSolver solver)
      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
      solver - Root-finding algorithm to use to detect state events

  • Method Details

    • getEventHandler

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

    • setExpandable

      public void setExpandable(ExpandableStatefulODE expandable)
      Set the equation.
      Parameters:
      expandable - equation being integrated

    • 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 MaxCountExceededException
      Reinitialize the beginning of the step.
      Parameters:
      interpolator - valid for the current step
      Throws:
      MaxCountExceededException - if the interpolator throws one because the number of functions evaluations is exceeded

    • getCompleteState

      private double[] getCompleteState(StepInterpolator interpolator)
      Get the complete state (primary and secondary).
      Parameters:
      interpolator - interpolator to use
      Returns:
      complete state

    • evaluateStep

      public boolean evaluateStep(StepInterpolator interpolator) throws MaxCountExceededException, NoBracketingException
      Evaluate the impact of the proposed step on the event handler.
      Parameters:
      interpolator - step interpolator for the proposed step
      Returns:
      true if the event handler triggers an event before the end of the proposed step
      Throws:
      MaxCountExceededException - if the interpolator throws one because the number of functions evaluations is exceeded
      NoBracketingException - if the event cannot be bracketed

    • 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 infinity if no events are triggered

    • stepAccepted

      public void stepAccepted(double t, double[] y)
      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

    • 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)
      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