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

Example 56 with Enrollment

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

the class SectionLimit method computeConflicts.

/**
     * A given enrollment is conflicting, if there is a section which limit
     * (computed by {@link SectionLimit#getEnrollmentWeight(Assignment, Section, Request)})
     * exceeds the section limit. <br>
     * For each of such sections, one or more existing enrollments are
     * (randomly) selected as conflicting until the overall weight is under the
     * limit.
     * 
     * @param enrollment
     *            {@link Enrollment} that is being considered
     * @param conflicts
     *            all computed conflicting requests are added into this set
     */
@Override
public void computeConflicts(Assignment<Request, Enrollment> assignment, Enrollment enrollment, Set<Enrollment> conflicts) {
    // check reservation can assign over the limit
    if (enrollment.getReservation() != null && enrollment.getReservation().canBatchAssignOverLimit())
        return;
    // exclude free time requests
    if (!enrollment.isCourseRequest())
        return;
    // for each section
    for (Section section : enrollment.getSections()) {
        // no reservation -- check the space in the unreserved space in the section
        if (enrollment.getConfig().getOffering().hasReservations() && !hasSectionReservation(enrollment, section)) {
            // section is fully reserved by section reservations
            if (section.getTotalUnreservedSpace() < enrollment.getRequest().getWeight()) {
                conflicts.add(enrollment);
                return;
            }
            double unreserved = getUnreservedSpace(assignment, section, enrollment.getRequest());
            if (unreserved < 0.0) {
                // no unreserved space available -> cannot be assigned
                // try to unassign some other enrollments that also do not have reservation
                List<Enrollment> adepts = new ArrayList<Enrollment>(section.getEnrollments(assignment).size());
                for (Enrollment e : section.getEnrollments(assignment)) {
                    if (e.getRequest().equals(enrollment.getRequest()))
                        continue;
                    if (e.getReservation() != null && e.getReservation().canBatchAssignOverLimit())
                        continue;
                    if (hasSectionReservation(e, section))
                        continue;
                    if (conflicts.contains(e))
                        unreserved += e.getRequest().getWeight();
                    else
                        adepts.add(e);
                }
                while (unreserved < 0.0) {
                    if (adepts.isEmpty()) {
                        // no adepts -> enrollment cannot be assigned
                        conflicts.add(enrollment);
                        return;
                    }
                    // pick adept (prefer dummy students), decrease unreserved space,
                    // make conflict
                    List<Enrollment> best = new ArrayList<Enrollment>();
                    boolean bestDummy = false;
                    double bestValue = 0;
                    for (Enrollment adept : adepts) {
                        boolean dummy = adept.getStudent().isDummy();
                        double value = adept.toDouble(assignment, false);
                        if (iPreferDummyStudents && dummy != bestDummy) {
                            if (dummy) {
                                best.clear();
                                best.add(adept);
                                bestDummy = dummy;
                                bestValue = value;
                            }
                            continue;
                        }
                        if (best.isEmpty() || value > bestValue) {
                            if (best.isEmpty())
                                best.clear();
                            best.add(adept);
                            bestDummy = dummy;
                            bestValue = value;
                        } else if (bestValue == value) {
                            best.add(adept);
                        }
                    }
                    Enrollment conflict = ToolBox.random(best);
                    adepts.remove(conflict);
                    unreserved += conflict.getRequest().getWeight();
                    conflicts.add(conflict);
                }
            }
        }
        // unlimited section
        if (section.getLimit() < 0)
            continue;
        // new enrollment weight
        double enrlWeight = getEnrollmentWeight(assignment, section, enrollment.getRequest());
        // below limit -> ok
        if (enrlWeight <= section.getLimit())
            continue;
        // above limit -> compute adepts (current assignments that are not
        // yet conflicting) exclude all conflicts as well
        List<Enrollment> adepts = new ArrayList<Enrollment>(section.getEnrollments(assignment).size());
        for (Enrollment e : section.getEnrollments(assignment)) {
            if (e.getRequest().equals(enrollment.getRequest()))
                continue;
            if (conflicts.contains(e))
                enrlWeight -= e.getRequest().getWeight();
            else
                adepts.add(e);
        }
        // while above limit -> pick an adept and make it conflicting
        while (enrlWeight > section.getLimit()) {
            if (adepts.isEmpty()) {
                // no adepts -> enrollment cannot be assigned
                conflicts.add(enrollment);
                return;
            }
            // pick adept (prefer dummy students & students w/o reservation), decrease enrollment
            // weight, make conflict
            List<Enrollment> best = new ArrayList<Enrollment>();
            boolean bestDummy = false;
            double bestValue = 0;
            boolean bestRes = true;
            for (Enrollment adept : adepts) {
                boolean dummy = adept.getStudent().isDummy();
                double value = adept.toDouble(assignment, false);
                boolean res = hasSectionReservation(adept, section);
                if (iPreferDummyStudents && dummy != bestDummy) {
                    if (dummy) {
                        best.clear();
                        best.add(adept);
                        bestDummy = dummy;
                        bestValue = value;
                        bestRes = res;
                    }
                    continue;
                }
                if (bestRes != res) {
                    if (!res) {
                        best.clear();
                        best.add(adept);
                        bestDummy = dummy;
                        bestValue = value;
                        bestRes = res;
                    }
                    continue;
                }
                if (best.isEmpty() || value > bestValue) {
                    if (best.isEmpty())
                        best.clear();
                    best.add(adept);
                    bestDummy = dummy;
                    bestValue = value;
                    bestRes = res;
                } else if (bestValue == value) {
                    best.add(adept);
                }
            }
            Enrollment conflict = ToolBox.random(best);
            adepts.remove(conflict);
            enrlWeight -= conflict.getRequest().getWeight();
            conflicts.add(conflict);
        }
    }
}

Example 57 with Enrollment

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

the class EnrollmentSelection method isAllowed.

/** true, if it is allowed to assign given value 
     * @param assignment current assignment
     * @param value given value
     * @param conflicts conflicting assignments
     * @return true if it is allowed
     **/
public boolean isAllowed(Assignment<Request, Enrollment> assignment, Enrollment value, Set<Enrollment> conflicts) {
    if (value == null)
        return true;
    StudentSectioningModel model = (StudentSectioningModel) value.variable().getModel();
    if (model.getNrLastLikeRequests(false) == 0 || model.getNrRealRequests(false) == 0)
        return true;
    Request request = value.variable();
    if (request.getStudent().isDummy()) {
        if (conflicts == null)
            conflicts = value.variable().getModel().conflictValues(assignment, value);
        for (Enrollment conflict : conflicts) {
            if (!conflict.getRequest().getStudent().isDummy())
                return false;
        }
    } else {
        if (conflicts == null)
            conflicts = value.variable().getModel().conflictValues(assignment, value);
        if (conflicts.size() > (assignment.getValue(request) == null ? 1 : 0))
            return false;
    }
    return true;
}

Example 58 with Enrollment

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

the class OnlineSelection method updateSpace.

/** Update online sectioning info after the given student is sectioned 
     * @param assignment current assignment
     * @param student student in question
     **/
public void updateSpace(Assignment<Request, Enrollment> assignment, Student student) {
    for (Request request : student.getRequests()) {
        if (!(request instanceof CourseRequest))
            continue;
        CourseRequest courseRequest = (CourseRequest) request;
        Enrollment enrollment = assignment.getValue(courseRequest);
        if (enrollment == null)
            // not enrolled --> no update
            return;
        for (Section section : enrollment.getSections()) {
            section.setSpaceHeld(section.getSpaceHeld() - courseRequest.getWeight());
        // sLog.debug("  -- space held for "+section+" decreased by 1 (to "+section.getSpaceHeld()+")");
        }
        List<Enrollment> feasibleEnrollments = new ArrayList<Enrollment>();
        for (Enrollment enrl : courseRequest.values(assignment)) {
            boolean overlaps = false;
            for (Request otherRequest : courseRequest.getStudent().getRequests()) {
                if (otherRequest.equals(courseRequest) || !(otherRequest instanceof CourseRequest))
                    continue;
                Enrollment otherErollment = assignment.getValue(otherRequest);
                if (otherErollment == null)
                    continue;
                if (enrl.isOverlapping(otherErollment)) {
                    overlaps = true;
                    break;
                }
            }
            if (!overlaps)
                feasibleEnrollments.add(enrl);
        }
        double decrement = courseRequest.getWeight() / feasibleEnrollments.size();
        for (Enrollment feasibleEnrollment : feasibleEnrollments) {
            for (Section section : feasibleEnrollment.getSections()) {
                section.setSpaceExpected(section.getSpaceExpected() - decrement);
            // sLog.debug("  -- space expected for "+section+" decreased by "+decrement+" (to "+section.getSpaceExpected()+")");
            }
        }
    }
}

Example 59 with Enrollment

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

the class PriorityConstructionSelection method branchAndBound.

/**
     * Find best solution for the next student using {@link BranchBoundSelection}.
     * @param solution current selection
     * @return generated neighbour
     */
public Neighbour<Request, Enrollment> branchAndBound(Solution<Request, Enrollment> solution) {
    while (iStudentsEnumeration.hasNext()) {
        Student student = iStudentsEnumeration.next();
        Progress.getInstance(solution.getModel()).incProgress();
        /*
            if (student.nrRequests() < iCycle) {
                // not enough requests -> nothing to improve -> skip
                continue;
            }
            if (student.nrAssignedRequests() + 1 < iCycle) {
                // previous step cycle already did not improve the assignment -> skip
                continue;
            }
            */
        Neighbour<Request, Enrollment> neighbour = iBranchBoundSelection.getSelection(solution.getAssignment(), student).select();
        if (neighbour != null)
            return neighbour;
    }
    return null;
}