Examples of CTDirector

ptolemy.domains.ct.kernel.CTDirector
Abstract base class for directors in the CT domain. A CTDirector has a CTScheduler which provides static schedules for firing the actors in different phases of execution in one iteration.
A CTDirector may have more than one ODE solver. In each phase of execution, one ODE solver takes charge of solving the behavior of a model. This solver is called the current ODE solver.
The continuous time (CT) domain is a timed domain. There is a global notion of time that all the actors are aware of. Time is maintained by the director. The method getModelTime() returns the current notion of model time. Time can be set by the setModelTime() method, but this method should not the called by the actors. Time can only be set by directors or their ODE solvers. Because ODE solvers can change time in their fire() methods, we need to record the beginning time of an iteration to support roll back. The _setIterationBeginTime() method is just designed for this purpose. It is called in the prefire() method of each iteration to store the beginning time, and the getIterationBeginTime() returns the lastest stored time.
This base class maintains a list of parameters that may be used by ODE solvers and actors. These parameters are:
startTime: The start time of the simulation. This parameter is effective only if the director is at the top level. The default value is 0.0.
stopTime: The stop time of the simulation. This parameter is effective only if the director is at the top level. The default value is Infinity, which results in execution that does not stop on its own.
initStepSize: The suggested integration step size by the user. This will be the step size for fixed step size ODE solvers if there is no breakpoint. However, it is just a hint. The default value is 0.1
minStepSize: The minimum step size that users want to use in the simulation. The default value is 1e-5.
maxStepSize: The maximum step size that users want to use in the simulation. Usually used to control the simulation speed. The default value is 1.0.
maxIterations: Used only in implicit ODE solvers. This is the maximum number of iterations for finding the fixed point at one time point. The default value is 20.
errorTolerance: This is the local truncation error tolerance, used for controlling the integration accuracy in variable step size ODE solvers. If the local truncation error at some step size control actors are greater than this tolerance, then the integration step is considered to have failed, and should be restarted with a reduced step size. The default value is 1e-4.
valueResolution: This is used to control the convergence of fixed point iterations. If in two successive iterations the difference of the state variables is less than this resolution, then the fixed point is considered to have reached. The default value is 1e-6.
This director maintains a breakpoint table to record all predictable breakpoints that are greater than or equal to the current time. The breakpoints are sorted in their chronological order. Breakpoints at the same time are considered to be identical, and the breakpoint table does not contain duplicate time points. A breakpoint can be inserted into the table by calling the fireAt() method. The fireAt method may be requested by the director, which inserts the stop time of the execution. The fireAt method may also be requested by actors and the requested firing time will be inserted into the breakpoint table. @author Jie Liu, Haiyang Zheng @version $Id: CTDirector.java,v 1.203 2007/12/06 18:21:49 cxh Exp $ @since Ptolemy II 0.2 @Pt.ProposedRating Green (hyzheng) @Pt.AcceptedRating Green (hyzheng)

Examples of ptolemy.domains.ct.kernel.CTDirector

     *  @exception IllegalActionException If thrown by the supper class.
     */
    public void initialize() throws IllegalActionException {
        super.initialize();


        CTDirector dir = (CTDirector) getDirector();
        _nextSamplingTime = dir.getModelTime();


        if (_debugging) {
            _debug("Next sampling time is at " + _nextSamplingTime);
        }
    }

Examples of ptolemy.domains.ct.kernel.CTDirector

     *  @return True.
     *  @exception IllegalActionException If the next sampling time can not be
     *  set as a breakpoint.
     */
    public boolean postfire() throws IllegalActionException {
        CTDirector director = (CTDirector) getDirector();


        if ((director.getExecutionPhase() == CTExecutionPhase.GENERATING_EVENTS_PHASE)
                && hasCurrentEvent()) {
            // register for the next event.
            _nextSamplingTime = _nextSamplingTime.add(_samplePeriod);


            if (_debugging) {

Examples of ptolemy.domains.ct.kernel.CTDirector

    /** Return half the current step size if the step crosses the threshold.
     *  Otherwise, return the current step size.
     *  @return Half of the current step size if the step is not accurate.
     */
    public double refinedStepSize() {
        CTDirector dir = (CTDirector) getDirector();


        if (!_accurate) {
            return 0.5 * dir.getCurrentStepSize();
        }


        return dir.getCurrentStepSize();
    }

Examples of ptolemy.domains.ct.kernel.CTDirector

     *  step will use the initial step size.
     *  @param integrator The integrator of that calls this method.
     *  @return The initial step size.
     */
    public double integratorPredictedStepSize(CTBaseIntegrator integrator) {
        CTDirector director = (CTDirector) getContainer();
        return director.getInitialStepSize();
    }

Examples of ptolemy.domains.ct.kernel.CTDirector

        // First assume that the states will converge after this round.
        // If any integrator does not agree, the final converged status may be
        // changed via calling _voteForConverged() by that integrator.
        _setConverged(true);


        CTDirector director = (CTDirector) getContainer();
        super.fireDynamicActors();


        if (_getRoundCount() == 0) {
            _recalculatingWithTwoSteps = false;
            _firstStep = true;
            director.setModelTime(director.getModelTime().add(
                    director.getCurrentStepSize()));
        }


        if (_isConverged()) {
            // Resolved states have converged.
            // We need to recalculate the states with two steps.

Examples of ptolemy.domains.ct.kernel.CTDirector

     *  @exception IllegalActionException If there is no director, or can not
     *  read input, or send output.
     */
    public void integratorFire(CTBaseIntegrator integrator)
            throws IllegalActionException {
        CTDirector director = (CTDirector) getContainer();
        double h = director.getCurrentStepSize();
        double tentativeState;


        if (_getRoundCount() == 0) {
            // During the first round, use the current derivative to predict
            // the states at currentModelTime + currentStepSize. The predicted
            // states are the initial guesses for fixed-point iteration.
            double f1 = integrator.getDerivative();
            tentativeState = integrator.getState() + (f1 * h);


            // Set converged to false such that the integrator will be refired
            // again to check convergence of resolved states.
            _voteForConverged(false);
        } else {
            // get the derivative at the beginning time of current integration.
            double f1 = integrator.getDerivative();


            // get predicated derivative at the end time of current integration.
            double f2 = ((DoubleToken) integrator.input.get(0)).doubleValue();


            if (!_recalculatingWithTwoSteps) {
                tentativeState = integrator.getState()
                        + ((h * (f1 + f2)) / 2.0);


                double error = Math.abs(tentativeState
                        - integrator.getTentativeState());


                if (error < director.getValueResolution()) {
                    // save resolved states for local truncation error control
                    integrator.setAuxVariables(0, tentativeState);
                    _voteForConverged(true);
                } else {
                    _voteForConverged(false);

Examples of ptolemy.domains.ct.kernel.CTDirector

     *  @param integrator The integrator that calls this method.
     *  @return True if the local truncation error is less than the
     *  error tolerance.
     */
    public boolean integratorIsAccurate(CTBaseIntegrator integrator) {
        CTDirector director = (CTDirector) getContainer();
        double tolerance = director.getErrorTolerance();
        double[] k = integrator.getAuxVariables();
        double localError = (1.0 / 3.0)
                * Math.abs(integrator.getTentativeState() - k[0]);
        integrator.setAuxVariables(1, localError);

Examples of ptolemy.domains.ct.kernel.CTDirector

     *  </pre>
     *  @param integrator The integrator of that calls this method.
     *  @return The suggested next step by the given integrator.
     */
    public double integratorPredictedStepSize(CTBaseIntegrator integrator) {
        CTDirector director = (CTDirector) getContainer();
        double localError = (integrator.getAuxVariables())[1];
        double h = director.getCurrentStepSize();
        double tolerance = director.getErrorTolerance();
        double newh = h;


        if ((localError / tolerance) < 0.1) {
            newh = h
                    * Math.min(2, Math.pow(((3.0 * tolerance) / localError),

Examples of ptolemy.domains.ct.kernel.CTDirector

     *  <i>maxIterations</i> number. Mean while, the round count is reset.
     *  @return True if the resolved states have converged.
     *  @exception IllegalActionException Not thrown in this base class.
     */
    public boolean resolveStates() throws IllegalActionException {
        CTDirector director = (CTDirector) getContainer();


        if (_getRoundCount() > director.getMaxIterations()) {
            _resetRoundCount();
            return false;
        }


        return super.resolveStates();

Examples of ptolemy.domains.ct.kernel.CTDirector

     *  @exception IllegalActionException If there is no director, or can not
     *  read input, or can not send output.
     */
    public void integratorFire(CTBaseIntegrator integrator)
            throws IllegalActionException {
        CTDirector director = (CTDirector) getContainer();
        double tentativeState = integrator.getState();


        if (_getRoundCount() == 0) {
            // During the first round, use the current derivative to predict
            // the states at currentModelTime + currentStepSize. The predicted
            // states are the initial guesses for fixed-point iteration.
            double f = integrator.getDerivative();
            tentativeState = tentativeState
                    + (f * (director.getCurrentStepSize()));


            // Set converged to false such that the integrator will be refired
            // again to check convergence of resolved states.
            _voteForConverged(false);
        } else {
            // Not the first round, keep iterating until resolved states
            // converge.
            double f = ((DoubleToken) integrator.input.get(0)).doubleValue();
            tentativeState = tentativeState
                    + (f * (director.getCurrentStepSize()));


            double error = Math.abs(tentativeState
                    - integrator.getTentativeState());


            if (error < director.getValueResolution()) {
                integrator.setTentativeDerivative(f);


                // Note that the FixedStepSolver sets converged to true for
                // each round by default. Therefore, we do not need to set it
                // to true again.