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.

    Since:
    1.2
    • Field Detail

      • 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.
      • 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)
      • solver

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

      • 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 Detail

      • 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
      • 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