Examples with Enrollment org.cpsolver.studentsct.model.Enrollment used on opensource projects

Example 6 with Enrollment

use of org.cpsolver.studentsct.model.Enrollment in project cpsolver by UniTime.

the class EnrollmentSelection method selectValue.

/** Value selection */
@Override
public Enrollment selectValue(Solution<Request, Enrollment> solution, Request selectedVariable) {
    Assignment<Request, Enrollment> assignment = solution.getAssignment();
    if (iMPP) {
        if (selectedVariable.getInitialAssignment() != null) {
            if (solution.getModel().unassignedVariables(assignment).isEmpty()) {
                if (solution.getModel().perturbVariables(assignment).size() <= iMPPLimit)
                    iMPPLimit = solution.getModel().perturbVariables(assignment).size() - 1;
            }
            if (iMPPLimit >= 0 && solution.getModel().perturbVariables(assignment).size() > iMPPLimit) {
                if (isAllowed(assignment, selectedVariable.getInitialAssignment()))
                    return selectedVariable.getInitialAssignment();
            }
            if (selectedVariable.getInitialAssignment() != null && ToolBox.random() <= iInitialSelectionProb) {
                if (isAllowed(assignment, selectedVariable.getInitialAssignment()))
                    return selectedVariable.getInitialAssignment();
            }
        }
    }
    List<Enrollment> values = selectedVariable.values(assignment);
    if (ToolBox.random() <= iRandomWalkProb) {
        Enrollment value = ToolBox.random(values);
        if (isAllowed(assignment, value))
            return value;
    }
    if (iProp != null && assignment.getValue(selectedVariable) == null && ToolBox.random() <= iGoodSelectionProb) {
        Set<Enrollment> goodValues = iProp.goodValues(assignment, selectedVariable);
        if (!goodValues.isEmpty())
            values = new ArrayList<Enrollment>(goodValues);
    }
    if (values.size() == 1) {
        Enrollment value = values.get(0);
        if (isAllowed(assignment, value))
            return value;
        else
            return null;
    }
    List<Enrollment> bestValues = null;
    double bestWeightedSum = 0;
    for (Enrollment value : values) {
        if (iTabu != null && iTabu.contains(value))
            continue;
        if (assignment.getValue(selectedVariable) != null && assignment.getValue(selectedVariable).equals(value))
            continue;
        Set<Enrollment> conf = solution.getModel().conflictValues(assignment, value);
        if (conf.contains(value))
            continue;
        if (!isAllowed(assignment, value, conf))
            continue;
        double weightedConflicts = (iStat == null || iWeightWeightedCoflicts == 0.0 ? 0.0 : iStat.countRemovals(solution.getIteration(), conf, value));
        double potentialConflicts = (iStat == null || iWeightPotentialConflicts == 0.0 ? 0.0 : iStat.countPotentialConflicts(assignment, solution.getIteration(), value, 3));
        long deltaInitialAssignments = 0;
        if (iMPP && iWeightDeltaInitialAssignment != 0.0) {
            if (iViolatedInitials != null) {
                Set<Enrollment> violations = iViolatedInitials.getViolatedInitials(value);
                if (violations != null) {
                    for (Enrollment aValue : violations) {
                        if (assignment.getValue(aValue.variable()) == null || assignment.getValue(aValue.variable()).equals(aValue))
                            deltaInitialAssignments += 2;
                    }
                }
            }
            for (Enrollment aValue : conf) {
                if (aValue.variable().getInitialAssignment() != null)
                    deltaInitialAssignments--;
            }
            if (selectedVariable.getInitialAssignment() != null && !selectedVariable.getInitialAssignment().equals(value)) {
                deltaInitialAssignments++;
            }
            if (iMPPLimit >= 0 && (solution.getModel().perturbVariables(assignment).size() + deltaInitialAssignments) > iMPPLimit)
                continue;
        }
        double weightedSum = (iWeightDeltaInitialAssignment * deltaInitialAssignments) + (iWeightPotentialConflicts * potentialConflicts) + (iWeightWeightedCoflicts * weightedConflicts) + (iWeightCoflicts * conf.size()) + (iWeightValue * value.toDouble(assignment));
        if (bestValues == null || bestWeightedSum > weightedSum) {
            bestWeightedSum = weightedSum;
            if (bestValues == null)
                bestValues = new ArrayList<Enrollment>();
            else
                bestValues.clear();
            bestValues.add(value);
        } else {
            if (bestWeightedSum == weightedSum)
                bestValues.add(value);
        }
    }
    Enrollment selectedValue = (bestValues == null ? null : ToolBox.random(bestValues));
    if (selectedValue == null)
        selectedValue = ToolBox.random(values);
    if (iTabu != null) {
        if (iTabu.size() == iTabuPos)
            iTabu.add(selectedValue);
        else
            iTabu.set(iTabuPos, selectedValue);
        iTabuPos = (iTabuPos + 1) % iTabuSize;
    }
    return (bestValues == null ? null : selectedValue);
}

Example 7 with Enrollment

use of org.cpsolver.studentsct.model.Enrollment in project cpsolver by UniTime.

the class RandomizedBacktrackNeighbourSelection method values.

/**
     * List of values of a variable.
     * {@link CourseRequest#computeRandomEnrollments(Assignment, int)} with the provided
     * limit is used for a {@link CourseRequest}.
     */
@Override
protected Iterator<Enrollment> values(BacktrackNeighbourSelection<Request, Enrollment>.BacktrackNeighbourSelectionContext<Request, Enrollment> context, Request variable) {
    if (variable instanceof CourseRequest) {
        final CourseRequest request = (CourseRequest) variable;
        final StudentSectioningModel model = (StudentSectioningModel) context.getModel();
        final Assignment<Request, Enrollment> assignment = context.getAssignment();
        List<Enrollment> values = (iMaxValues > 0 ? request.computeRandomEnrollments(assignment, iMaxValues) : request.computeEnrollments(assignment));
        Collections.sort(values, new Comparator<Enrollment>() {

            private HashMap<Enrollment, Double> iValues = new HashMap<Enrollment, Double>();

            private Double value(Enrollment e) {
                Double value = iValues.get(e);
                if (value == null) {
                    value = model.getStudentWeights().getWeight(assignment, e, (model.getDistanceConflict() == null ? null : model.getDistanceConflict().conflicts(e)), (model.getTimeOverlaps() == null ? null : model.getTimeOverlaps().conflicts(e)));
                    iValues.put(e, value);
                }
                return value;
            }

            @Override
            public int compare(Enrollment e1, Enrollment e2) {
                if (e1.equals(assignment.getValue(request)))
                    return -1;
                if (e2.equals(assignment.getValue(request)))
                    return 1;
                Double v1 = value(e1), v2 = value(e2);
                return v1.equals(v2) ? e1.compareTo(assignment, e2) : v2.compareTo(v1);
            }
        });
        return values.iterator();
    } else {
        return variable.computeEnrollments(context.getAssignment()).iterator();
    }
}

Example 8 with Enrollment

use of org.cpsolver.studentsct.model.Enrollment in project cpsolver by UniTime.

the class BranchBoundSelection method selectNeighbour.

/**
     * Select neighbour. All students are taken, one by one in a random order.
     * For each student a branch & bound search is employed.
     */
@Override
public Neighbour<Request, Enrollment> selectNeighbour(Solution<Request, Enrollment> solution) {
    Student student = null;
    while ((student = nextStudent()) != null) {
        Progress.getInstance(solution.getModel()).incProgress();
        Neighbour<Request, Enrollment> neighbour = getSelection(solution.getAssignment(), student).select();
        if (neighbour != null)
            return neighbour;
    }
    return null;
}

Example 9 with Enrollment

use of org.cpsolver.studentsct.model.Enrollment in project cpsolver by UniTime.

the class ResectionIncompleteStudentsSelection method selectNeighbour.

/**
     * Select neighbour. All students with an incomplete and non-empty schedule
     * are taken, one by one in a random order. For each student a branch & 
     * bound search is employed.
     */
@Override
public Neighbour<Request, Enrollment> selectNeighbour(Solution<Request, Enrollment> solution) {
    Student student = null;
    while ((student = nextStudent()) != null) {
        Progress.getInstance(solution.getModel()).incProgress();
        if (student.nrAssignedRequests(solution.getAssignment()) == 0 || student.isComplete(solution.getAssignment()))
            continue;
        Neighbour<Request, Enrollment> neighbour = getSelection(solution.getAssignment(), student).select();
        if (neighbour != null)
            return neighbour;
    }
    return null;
}

Example 10 with Enrollment

use of org.cpsolver.studentsct.model.Enrollment in project cpsolver by UniTime.

the class StudentConflict method computeConflicts.

/**
     * A given enrollment is conflicting when the student is enrolled into
     * another course / free time request that has an assignment that is
     * overlapping with one or more assignments of the given section. See
     * {@link Enrollment#isOverlapping(Enrollment)} for more details. All such
     * overlapping enrollments are added into the provided set of conflicts.
     * 
     * @param enrollment
     *            {@link Enrollment} that is being considered
     * @param conflicts
     *            resultant list of conflicting enrollments
     */
@Override
public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollment enrollment, Set<Enrollment> conflicts) {
    // enrollment -> conflict
    for (Request request : variables()) {
        if (request.equals(enrollment.getRequest()))
            continue;
        Enrollment e = assignment.getValue(request);
        if (e == null)
            continue;
        if (enrollment.isOverlapping(e))
            conflicts.add(e);
    }
    // schedule) -> unassignd a lowest priority request
    if (!enrollment.getAssignments().isEmpty() && !enrollment.getStudent().canAssign(assignment, enrollment.getRequest())) {
        Enrollment lowestPriorityEnrollment = null;
        int lowestPriority = -1;
        for (Request request : variables()) {
            if (request.equals(enrollment.getRequest()))
                continue;
            Enrollment e = assignment.getValue(request);
            if (e == null)
                continue;
            if (lowestPriority < request.getPriority()) {
                lowestPriority = request.getPriority();
                lowestPriorityEnrollment = e;
            }
        }
        if (lowestPriorityEnrollment != null)
            conflicts.add(lowestPriorityEnrollment);
    }
}