Class AbstractIntegrator

    • Constructor Detail

      • AbstractIntegrator

        protected AbstractIntegrator​(String name)
        Build an instance.
        Parameters:
        name - name of the method
    • Method Detail

      • getName

        public String getName()
        Get the name of the method.
        Specified by:
        getName in interface ODEIntegrator
        Returns:
        name of the method
      • addEventHandler

        public void addEventHandler​(ODEEventHandler handler,
                                    double maxCheckInterval,
                                    double convergence,
                                    int maxIterationCount)
        Add an event handler to the integrator.

        Uses a default UnivariateSolver with an absolute accuracy equal to the given convergence threshold, as root-finding algorithm to detect the state events.

        Specified by:
        addEventHandler in interface ODEIntegrator
        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. Must be smaller than maxCheckInterval and should be small compared to time scale of the ODE dynamics.
        maxIterationCount - upper limit of the iteration count in the event time search
        See Also:
        ODEIntegrator.getEventHandlers(), ODEIntegrator.clearEventHandlers()
      • addEventHandler

        public void addEventHandler​(ODEEventHandler handler,
                                    double maxCheckInterval,
                                    double convergence,
                                    int maxIterationCount,
                                    BracketedUnivariateSolver<UnivariateFunction> solver)
        Add an event handler to the integrator.
        Specified by:
        addEventHandler in interface ODEIntegrator
        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. Must be smaller than maxCheckInterval and should be small compared to time scale of the ODE dynamics.
        maxIterationCount - upper limit of the iteration count in the event time search
        solver - The root-finding algorithm to use to detect the state events.
        See Also:
        ODEIntegrator.getEventHandlers(), ODEIntegrator.clearEventHandlers()
      • getCurrentStepStart

        @Deprecated
        public double getCurrentStepStart()
        Deprecated.
        Get the current value of the step start time ti.

        This method can be called during integration (typically by the object implementing the differential equations problem) if the value of the current step that is attempted is needed.

        The result is undefined if the method is called outside of calls to integrate.

        Specified by:
        getCurrentStepStart in interface ODEIntegrator
        Returns:
        current value of the step start time ti
      • getCurrentSignedStepsize

        public double getCurrentSignedStepsize()
        Get the current signed value of the integration stepsize.

        This method can be called during integration (typically by the object implementing the differential equations problem) if the signed value of the current stepsize that is tried is needed.

        The result is undefined if the method is called outside of calls to integrate.

        Specified by:
        getCurrentSignedStepsize in interface ODEIntegrator
        Returns:
        current signed value of the stepsize
      • setMaxEvaluations

        public void setMaxEvaluations​(int maxEvaluations)
        Set the maximal number of differential equations function evaluations.

        The purpose of this method is to avoid infinite loops which can occur for example when stringent error constraints are set or when lots of discrete events are triggered, thus leading to many rejected steps.

        Specified by:
        setMaxEvaluations in interface ODEIntegrator
        Parameters:
        maxEvaluations - maximal number of function evaluations (negative values are silently converted to maximal integer value, thus representing almost unlimited evaluations)
      • getMaxEvaluations

        public int getMaxEvaluations()
        Get the maximal number of functions evaluations.
        Specified by:
        getMaxEvaluations in interface ODEIntegrator
        Returns:
        maximal number of functions evaluations
      • getEvaluations

        public int getEvaluations()
        Get the number of evaluations of the differential equations function.

        The number of evaluations corresponds to the last call to the integrate method. It is 0 if the method has not been called yet.

        Specified by:
        getEvaluations in interface ODEIntegrator
        Returns:
        number of evaluations of the differential equations function
      • initIntegration

        protected ODEStateAndDerivative initIntegration​(ExpandableODE eqn,
                                                        ODEState s0,
                                                        double t)
        Prepare the start of an integration.
        Parameters:
        eqn - equations to integrate
        s0 - initial state vector
        t - target time for the integration
        Returns:
        Initial state with computed derivatives.
      • getEquations

        protected ExpandableODE getEquations()
        Get the differential equations to integrate.
        Returns:
        differential equations to integrate
      • getEvaluationsCounter

        protected Incrementor getEvaluationsCounter()
        Get the evaluations counter.
        Returns:
        evaluations counter
      • setStateInitialized

        protected void setStateInitialized​(boolean stateInitialized)
        Set the stateInitialized flag.

        This method must be called by integrators with the value false before they start integration, so a proper lazy initialization is done automatically on the first step.

        Parameters:
        stateInitialized - new value for the flag
      • resetOccurred

        protected boolean resetOccurred()
        Check if a reset occurred while last step was accepted.
        Returns:
        true if a reset occurred while last step was accepted
      • setStepSize

        protected void setStepSize​(double stepSize)
        Set the current step size.
        Parameters:
        stepSize - step size to set
      • getStepSize

        protected double getStepSize()
        Get the current step size.
        Returns:
        current step size
      • setStepStart

        protected void setStepStart​(ODEStateAndDerivative stepStart)
        Set current step start.
        Parameters:
        stepStart - step start
      • getStepStart

        public ODEStateAndDerivative getStepStart()
        Get the state at step start time ti.

        This method can be called during integration (typically by the object implementing the differential equations problem) if the value of the current step that is attempted is needed.

        The result is undefined if the method is called outside of calls to integrate.

        Specified by:
        getStepStart in interface ODEIntegrator
        Returns:
        state at step start time ti
      • setIsLastStep

        protected void setIsLastStep​(boolean isLastStep)
        Set the last state flag.
        Parameters:
        isLastStep - if true, this step is the last one
      • isLastStep

        protected boolean isLastStep()
        Check if this step is the last one.
        Returns:
        true if this step is the last one