Examples with LazyNeighbour org.cpsolver.ifs.model.LazyNeighbour used on opensource projects

Example 1 with LazyNeighbour

use of org.cpsolver.ifs.model.LazyNeighbour in project cpsolver by UniTime.

the class ExamSimulatedAnnealing method accept.

/**
     * True if the given neighboir is to be be accepted
     * 
     * @param solution
     *            current solution
     * @param neighbour
     *            proposed move
     * @return true if generated random number is below
     *         {@link ExamSimulatedAnnealing.Context#prob(double)}
     */
protected boolean accept(Solution<Exam, ExamPlacement> solution, Neighbour<Exam, ExamPlacement> neighbour) {
    if (neighbour instanceof LazyNeighbour) {
        ((LazyNeighbour<Exam, ExamPlacement>) neighbour).setAcceptanceCriterion(this);
        return true;
    }
    Assignment<Exam, ExamPlacement> assignment = solution.getAssignment();
    double value = (iRelativeAcceptance ? neighbour.value(assignment) : solution.getModel().getTotalValue(assignment) + neighbour.value(assignment) - solution.getBestValue());
    Context context = getContext(solution.getAssignment());
    double prob = context.prob(value);
    if (prob >= 1.0 || ToolBox.random() < prob) {
        context.accepted(neighbour.value(assignment));
        return true;
    }
    return false;
}

Example 2 with LazyNeighbour

use of org.cpsolver.ifs.model.LazyNeighbour in project cpsolver by UniTime.

the class ExamHillClimbing method selectNeighbour.

/**
     * Select one of the given neighbourhoods randomly, select neighbour, return
     * it if its value is below or equal to zero (continue with the next
     * selection otherwise). Return null when the given number of idle
     * iterations is reached.
     */
@Override
public Neighbour<Exam, ExamPlacement> selectNeighbour(Solution<Exam, ExamPlacement> solution) {
    Context context = getContext(solution.getAssignment());
    context.activateIfNeeded();
    while (true) {
        if (context.incIter(solution))
            break;
        NeighbourSelection<Exam, ExamPlacement> ns = iNeighbours.get(ToolBox.random(iNeighbours.size()));
        Neighbour<Exam, ExamPlacement> n = ns.selectNeighbour(solution);
        if (n != null) {
            if (n instanceof LazyNeighbour) {
                ((LazyNeighbour<Exam, ExamPlacement>) n).setAcceptanceCriterion(this);
                return n;
            } else if (n.value(solution.getAssignment()) <= 0.0)
                return n;
        }
    }
    context.reset();
    return null;
}