Package org.apache.commons.math3.ode.events

Class FieldEventState<T extends RealFieldElement<T>>

java.lang.Object
org.apache.commons.math3.ode.events.FieldEventState<T>
Type Parameters:
T - the type of the field elements
public class FieldEventState<T extends RealFieldElement<T>> 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:
3.6

  • Field Details

    • handler

      private final FieldEventHandler<T extends RealFieldElement<T>> handler
      Event handler.

    • maxCheckInterval

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

    • convergence

      private final T extends RealFieldElement<T> convergence
      Convergence threshold for event localization.

    • maxIterationCount

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

    • t0

      private T extends RealFieldElement<T> t0
      Time at the beginning of the step.

    • g0

      private T extends RealFieldElement<T> 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 T extends RealFieldElement<T> pendingEventTime
      Occurrence time of the pending event.

    • previousEventTime

      private T extends RealFieldElement<T> 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 Action nextAction
      Next action indicator.

    • solver

      private final BracketedRealFieldUnivariateSolver<T extends RealFieldElement<T>> solver
      Root-finding algorithm to use to detect state events.

  • Constructor Details

    • FieldEventState

      public FieldEventState(FieldEventHandler<T> handler, double maxCheckInterval, T convergence, int maxIterationCount, BracketedRealFieldUnivariateSolver<T> 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 FieldEventHandler<T> 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 T 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(FieldStepInterpolator<T> 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

    • evaluateStep

      public boolean evaluateStep(FieldStepInterpolator<T> 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 T 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(FieldODEStateAndDerivative<T> state)
      Acknowledge the fact the step has been accepted by the integrator.
      Parameters:
      state - state 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 FieldODEState<T> reset(FieldODEStateAndDerivative<T> state)
      Let the event handler reset the state if it wants.
      Parameters:
      state - state at the beginning of the next step
      Returns:
      reset state (may by the same as initial state if only derivatives should be reset), or null if nothing is reset