Examples with BranchBoundNeighbour org.cpsolver.studentsct.heuristics.selection.BranchBoundSelection.BranchBoundNeighbour used on opensource projects

Example 1 with BranchBoundNeighbour

use of org.cpsolver.studentsct.heuristics.selection.BranchBoundSelection.BranchBoundNeighbour in project cpsolver by UniTime.

the class Test method section.

public boolean section(Student original) {
    OnlineSectioningModel model = new TestModel(iModel.getProperties());
    model.setOverExpectedCriterion(iModel.getOverExpectedCriterion());
    Student student = new Student(original.getId());
    Hashtable<CourseRequest, Set<Section>> preferredSectionsForCourse = new Hashtable<CourseRequest, Set<Section>>();
    Map<Long, Section> classTable = new HashMap<Long, Section>();
    synchronized (iModel) {
        for (Request request : original.getRequests()) {
            Request clonnedRequest = addRequest(student, original, request, classTable, model);
            Enrollment enrollment = assignment().getValue(request);
            if (enrollment != null && enrollment.isCourseRequest()) {
                Set<Section> sections = new HashSet<Section>();
                for (Section section : enrollment.getSections()) sections.add(classTable.get(section.getId()));
                preferredSectionsForCourse.put((CourseRequest) clonnedRequest, sections);
            }
        }
    }
    model.addStudent(student);
    model.setDistanceConflict(new DistanceConflict(iModel.getDistanceConflict().getDistanceMetric(), model.getProperties()));
    model.setTimeOverlaps(new TimeOverlapsCounter(null, model.getProperties()));
    for (LinkedSections link : iModel.getLinkedSections()) {
        List<Section> sections = new ArrayList<Section>();
        for (Offering offering : link.getOfferings()) for (Subpart subpart : link.getSubparts(offering)) for (Section section : link.getSections(subpart)) {
            Section x = classTable.get(section.getId());
            if (x != null)
                sections.add(x);
        }
        if (sections.size() >= 2)
            model.addLinkedSections(link.isMustBeUsed(), sections);
    }
    OnlineSectioningSelection selection = null;
    if (model.getProperties().getPropertyBoolean("StudentWeights.MultiCriteria", true)) {
        selection = new MultiCriteriaBranchAndBoundSelection(iModel.getProperties());
    } else {
        selection = new SuggestionSelection(model.getProperties());
    }
    selection.setModel(model);
    selection.setPreferredSections(preferredSectionsForCourse);
    selection.setRequiredSections(new Hashtable<CourseRequest, Set<Section>>());
    selection.setRequiredFreeTimes(new HashSet<FreeTimeRequest>());
    long t0 = JProf.currentTimeMillis();
    Assignment<Request, Enrollment> newAssignment = new AssignmentMap<Request, Enrollment>();
    BranchBoundNeighbour neighbour = selection.select(newAssignment, student);
    long time = JProf.currentTimeMillis() - t0;
    inc("[C] CPU Time", time);
    if (neighbour == null) {
        inc("[F] Failure");
    } else {
        if (iSuggestions) {
            StudentPreferencePenalties penalties = new StudentPreferencePenalties(StudentPreferencePenalties.sDistTypePreference);
            double maxOverExpected = 0;
            int assigned = 0;
            double penalty = 0.0;
            Hashtable<CourseRequest, Set<Section>> enrollments = new Hashtable<CourseRequest, Set<Section>>();
            List<RequestSectionPair> pairs = new ArrayList<RequestSectionPair>();
            for (int i = 0; i < neighbour.getAssignment().length; i++) {
                Enrollment enrl = neighbour.getAssignment()[i];
                if (enrl != null && enrl.isCourseRequest() && enrl.getAssignments() != null) {
                    assigned++;
                    for (Section section : enrl.getSections()) {
                        maxOverExpected += model.getOverExpected(newAssignment, section, enrl.getRequest());
                        pairs.add(new RequestSectionPair(enrl.variable(), section));
                    }
                    enrollments.put((CourseRequest) enrl.variable(), enrl.getSections());
                    penalty += penalties.getPenalty(enrl);
                }
            }
            penalty /= assigned;
            inc("[S] Initial Penalty", penalty);
            double nrSuggestions = 0.0, nrAccepted = 0.0, totalSuggestions = 0.0, nrTries = 0.0;
            for (int i = 0; i < pairs.size(); i++) {
                RequestSectionPair pair = pairs.get(i);
                SuggestionsBranchAndBound suggestionBaB = null;
                if (model.getProperties().getPropertyBoolean("StudentWeights.MultiCriteria", true)) {
                    suggestionBaB = new MultiCriteriaBranchAndBoundSuggestions(model.getProperties(), student, newAssignment, new Hashtable<CourseRequest, Set<Section>>(), new HashSet<FreeTimeRequest>(), enrollments, pair.getRequest(), pair.getSection(), null, maxOverExpected, iModel.getProperties().getPropertyBoolean("StudentWeights.PriorityWeighting", true));
                } else {
                    suggestionBaB = new SuggestionsBranchAndBound(model.getProperties(), student, newAssignment, new Hashtable<CourseRequest, Set<Section>>(), new HashSet<FreeTimeRequest>(), enrollments, pair.getRequest(), pair.getSection(), null, maxOverExpected);
                }
                long x0 = JProf.currentTimeMillis();
                TreeSet<SuggestionsBranchAndBound.Suggestion> suggestions = suggestionBaB.computeSuggestions();
                inc("[S] Suggestion CPU Time", JProf.currentTimeMillis() - x0);
                totalSuggestions += suggestions.size();
                if (!suggestions.isEmpty())
                    nrSuggestions += 1.0;
                nrTries += 1.0;
                SuggestionsBranchAndBound.Suggestion best = null;
                for (SuggestionsBranchAndBound.Suggestion suggestion : suggestions) {
                    int a = 0;
                    double p = 0.0;
                    for (int j = 0; j < suggestion.getEnrollments().length; j++) {
                        Enrollment e = suggestion.getEnrollments()[j];
                        if (e != null && e.isCourseRequest() && e.getAssignments() != null) {
                            p += penalties.getPenalty(e);
                            a++;
                        }
                    }
                    p /= a;
                    if (a > assigned || (assigned == a && p < penalty)) {
                        best = suggestion;
                    }
                }
                if (best != null) {
                    nrAccepted += 1.0;
                    Enrollment[] e = best.getEnrollments();
                    for (int j = 0; j < e.length; j++) if (e[j] != null && e[j].getAssignments() == null)
                        e[j] = null;
                    neighbour = new BranchBoundNeighbour(student, best.getValue(), e);
                    assigned = 0;
                    penalty = 0.0;
                    enrollments.clear();
                    pairs.clear();
                    for (int j = 0; j < neighbour.getAssignment().length; j++) {
                        Enrollment enrl = neighbour.getAssignment()[j];
                        if (enrl != null && enrl.isCourseRequest() && enrl.getAssignments() != null) {
                            assigned++;
                            for (Section section : enrl.getSections()) pairs.add(new RequestSectionPair(enrl.variable(), section));
                            enrollments.put((CourseRequest) enrl.variable(), enrl.getSections());
                            penalty += penalties.getPenalty(enrl);
                        }
                    }
                    penalty /= assigned;
                    inc("[S] Improved Penalty", penalty);
                }
            }
            inc("[S] Final Penalty", penalty);
            if (nrSuggestions > 0) {
                inc("[S] Classes with suggestion", nrSuggestions);
                inc("[S] Avg. # of suggestions", totalSuggestions / nrSuggestions);
                inc("[S] Suggestion acceptance rate [%]", nrAccepted / nrSuggestions);
            } else {
                inc("[S] Student with no suggestions available", 1.0);
            }
            if (!pairs.isEmpty())
                inc("[S] Probability that a class has suggestions [%]", nrSuggestions / nrTries);
        }
        List<Enrollment> enrollments = new ArrayList<Enrollment>();
        i: for (int i = 0; i < neighbour.getAssignment().length; i++) {
            Request request = original.getRequests().get(i);
            Enrollment clonnedEnrollment = neighbour.getAssignment()[i];
            if (clonnedEnrollment != null && clonnedEnrollment.getAssignments() != null) {
                if (request instanceof FreeTimeRequest) {
                    enrollments.add(((FreeTimeRequest) request).createEnrollment());
                } else {
                    for (Course course : ((CourseRequest) request).getCourses()) if (course.getId() == clonnedEnrollment.getCourse().getId())
                        for (Config config : course.getOffering().getConfigs()) if (config.getId() == clonnedEnrollment.getConfig().getId()) {
                            Set<Section> assignments = new HashSet<Section>();
                            for (Subpart subpart : config.getSubparts()) for (Section section : subpart.getSections()) {
                                if (clonnedEnrollment.getSections().contains(section)) {
                                    assignments.add(section);
                                }
                            }
                            Reservation reservation = null;
                            if (clonnedEnrollment.getReservation() != null) {
                                for (Reservation r : course.getOffering().getReservations()) if (r.getId() == clonnedEnrollment.getReservation().getId()) {
                                    reservation = r;
                                    break;
                                }
                            }
                            enrollments.add(new Enrollment(request, clonnedEnrollment.getPriority(), course, config, assignments, reservation));
                            continue i;
                        }
                }
            }
        }
        synchronized (iModel) {
            for (Request r : original.getRequests()) {
                Enrollment e = assignment().getValue(r);
                r.setInitialAssignment(e);
                if (e != null)
                    updateSpace(assignment(), e, true);
            }
            for (Request r : original.getRequests()) if (assignment().getValue(r) != null)
                assignment().unassign(0, r);
            boolean fail = false;
            for (Enrollment enrl : enrollments) {
                if (iModel.conflictValues(assignment(), enrl).isEmpty()) {
                    assignment().assign(0, enrl);
                } else {
                    fail = true;
                    break;
                }
            }
            if (fail) {
                for (Request r : original.getRequests()) if (assignment().getValue(r) != null)
                    assignment().unassign(0, r);
                for (Request r : original.getRequests()) if (r.getInitialAssignment() != null)
                    assignment().assign(0, r.getInitialAssignment());
                for (Request r : original.getRequests()) if (assignment().getValue(r) != null)
                    updateSpace(assignment(), assignment().getValue(r), false);
            } else {
                for (Enrollment enrl : enrollments) updateSpace(assignment(), enrl, false);
            }
            if (fail)
                return false;
        }
        neighbour.assign(newAssignment, 0);
        int a = 0, u = 0, np = 0, zp = 0, pp = 0, cp = 0;
        double over = 0;
        double p = 0.0;
        for (Request r : student.getRequests()) {
            if (r instanceof CourseRequest) {
                Enrollment e = newAssignment.getValue(r);
                if (e != null) {
                    for (Section s : e.getSections()) {
                        if (s.getPenalty() < 0.0)
                            np++;
                        if (s.getPenalty() == 0.0)
                            zp++;
                        if (s.getPenalty() > 0.0)
                            pp++;
                        if (s.getLimit() > 0) {
                            p += s.getPenalty();
                            cp++;
                        }
                        over += model.getOverExpected(newAssignment, s, r);
                    }
                    a++;
                } else {
                    u++;
                }
            }
        }
        inc("[A] Student");
        if (over > 0.0)
            inc("[O] Over", over);
        if (a > 0)
            inc("[A] Assigned", a);
        if (u > 0)
            inc("[A] Not Assigned", u);
        inc("[V] Value", neighbour.value(newAssignment));
        if (zp > 0)
            inc("[P] Zero penalty", zp);
        if (np > 0)
            inc("[P] Negative penalty", np);
        if (pp > 0)
            inc("[P] Positive penalty", pp);
        if (cp > 0)
            inc("[P] Average penalty", p / cp);
    }
    inc("[T0] Time <10ms", time < 10 ? 1 : 0);
    inc("[T1] Time <100ms", time < 100 ? 1 : 0);
    inc("[T2] Time <250ms", time < 250 ? 1 : 0);
    inc("[T3] Time <500ms", time < 500 ? 1 : 0);
    inc("[T4] Time <1s", time < 1000 ? 1 : 0);
    inc("[T5] Time >=1s", time >= 1000 ? 1 : 0);
    return true;
}

Example 2 with BranchBoundNeighbour

use of org.cpsolver.studentsct.heuristics.selection.BranchBoundSelection.BranchBoundNeighbour in project cpsolver by UniTime.

the class MultiCriteriaBranchAndBoundSelection method select.

/**
 * Execute branch & bound, return the best found schedule for the selected
 * student.
 */
public BranchBoundNeighbour select() {
    iT0 = JProf.currentTimeMillis();
    iTimeoutReached = false;
    iCurrentAssignment = new Enrollment[iStudent.getRequests().size()];
    iBestAssignment = null;
    int i = 0;
    for (Request r : iStudent.getRequests()) iCurrentAssignment[i++] = iAssignment.getValue(r);
    saveBest();
    for (int j = 0; j < iCurrentAssignment.length; j++) iCurrentAssignment[j] = null;
    iValues = new HashMap<CourseRequest, List<Enrollment>>();
    backTrack(0);
    iT1 = JProf.currentTimeMillis();
    if (iBestAssignment == null)
        return null;
    return new BranchBoundNeighbour(iStudent, iComparator.getTotalWeight(iAssignment, iBestAssignment), iBestAssignment);
}

Example 3 with BranchBoundNeighbour

use of org.cpsolver.studentsct.heuristics.selection.BranchBoundSelection.BranchBoundNeighbour in project cpsolver by UniTime.

the class Test method onlineSectioning.

/**
 * Online sectioning test
 * @param cfg solver configuration
 * @return resultant solution
 * @throws Exception thrown when the sectioning fails
 */
public static Solution<Request, Enrollment> onlineSectioning(DataProperties cfg) throws Exception {
    Solution<Request, Enrollment> solution = load(cfg);
    if (solution == null)
        return null;
    StudentSectioningModel model = (StudentSectioningModel) solution.getModel();
    Assignment<Request, Enrollment> assignment = solution.getAssignment();
    solution.addSolutionListener(new TestSolutionListener());
    double startTime = JProf.currentTimeSec();
    Solver<Request, Enrollment> solver = new Solver<Request, Enrollment>(cfg);
    solver.setInitalSolution(solution);
    solver.initSolver();
    OnlineSelection onlineSelection = new OnlineSelection(cfg);
    onlineSelection.init(solver);
    double totalPenalty = 0, minPenalty = 0, maxPenalty = 0;
    double minAvEnrlPenalty = 0, maxAvEnrlPenalty = 0;
    double totalPrefPenalty = 0, minPrefPenalty = 0, maxPrefPenalty = 0;
    double minAvEnrlPrefPenalty = 0, maxAvEnrlPrefPenalty = 0;
    int nrChoices = 0, nrEnrollments = 0, nrCourseRequests = 0;
    int chChoices = 0, chCourseRequests = 0, chStudents = 0;
    int choiceLimit = model.getProperties().getPropertyInt("Test.ChoicesLimit", -1);
    File outDir = new File(model.getProperties().getProperty("General.Output", "."));
    outDir.mkdirs();
    PrintWriter pw = new PrintWriter(new FileWriter(new File(outDir, "choices.csv")));
    List<Student> students = model.getStudents();
    try {
        @SuppressWarnings("rawtypes") Class studentOrdClass = Class.forName(model.getProperties().getProperty("Test.StudentOrder", StudentRandomOrder.class.getName()));
        @SuppressWarnings("unchecked") StudentOrder studentOrd = (StudentOrder) studentOrdClass.getConstructor(new Class[] { DataProperties.class }).newInstance(new Object[] { model.getProperties() });
        students = studentOrd.order(model.getStudents());
    } catch (Exception e) {
        sLog.error("Unable to reorder students, reason: " + e.getMessage(), e);
    }
    ShutdownHook hook = new ShutdownHook(solver);
    Runtime.getRuntime().addShutdownHook(hook);
    for (Student student : students) {
        if (student.nrAssignedRequests(assignment) > 0)
            // skip students with assigned courses (i.e., students
            continue;
        // already assigned by a batch sectioning process)
        sLog.info("Sectioning student: " + student);
        BranchBoundSelection.Selection selection = onlineSelection.getSelection(assignment, student);
        BranchBoundNeighbour neighbour = selection.select();
        if (neighbour != null) {
            StudentPreferencePenalties penalties = null;
            if (selection instanceof OnlineSelection.EpsilonSelection) {
                OnlineSelection.EpsilonSelection epsSelection = (OnlineSelection.EpsilonSelection) selection;
                penalties = epsSelection.getPenalties();
                for (int i = 0; i < neighbour.getAssignment().length; i++) {
                    Request r = student.getRequests().get(i);
                    if (r instanceof CourseRequest) {
                        nrCourseRequests++;
                        chCourseRequests++;
                        int chChoicesThisRq = 0;
                        CourseRequest request = (CourseRequest) r;
                        for (Enrollment x : request.getAvaiableEnrollments(assignment)) {
                            nrEnrollments++;
                            if (epsSelection.isAllowed(i, x)) {
                                nrChoices++;
                                if (choiceLimit <= 0 || chChoicesThisRq < choiceLimit) {
                                    chChoices++;
                                    chChoicesThisRq++;
                                }
                            }
                        }
                    }
                }
                chStudents++;
                if (chStudents == 100) {
                    pw.println(sDF.format(((double) chChoices) / chCourseRequests));
                    pw.flush();
                    chStudents = 0;
                    chChoices = 0;
                    chCourseRequests = 0;
                }
            }
            for (int i = 0; i < neighbour.getAssignment().length; i++) {
                if (neighbour.getAssignment()[i] == null)
                    continue;
                Enrollment enrollment = neighbour.getAssignment()[i];
                if (enrollment.getRequest() instanceof CourseRequest) {
                    CourseRequest request = (CourseRequest) enrollment.getRequest();
                    double[] avEnrlMinMax = getMinMaxAvailableEnrollmentPenalty(assignment, request);
                    minAvEnrlPenalty += avEnrlMinMax[0];
                    maxAvEnrlPenalty += avEnrlMinMax[1];
                    totalPenalty += enrollment.getPenalty();
                    minPenalty += request.getMinPenalty();
                    maxPenalty += request.getMaxPenalty();
                    if (penalties != null) {
                        double[] avEnrlPrefMinMax = penalties.getMinMaxAvailableEnrollmentPenalty(assignment, enrollment.getRequest());
                        minAvEnrlPrefPenalty += avEnrlPrefMinMax[0];
                        maxAvEnrlPrefPenalty += avEnrlPrefMinMax[1];
                        totalPrefPenalty += penalties.getPenalty(enrollment);
                        minPrefPenalty += penalties.getMinPenalty(enrollment.getRequest());
                        maxPrefPenalty += penalties.getMaxPenalty(enrollment.getRequest());
                    }
                }
            }
            neighbour.assign(assignment, solution.getIteration());
            sLog.info("Student " + student + " enrolls into " + neighbour);
            onlineSelection.updateSpace(assignment, student);
        } else {
            sLog.warn("No solution found.");
        }
        solution.update(JProf.currentTimeSec() - startTime);
        solution.saveBest();
    }
    if (chCourseRequests > 0)
        pw.println(sDF.format(((double) chChoices) / chCourseRequests));
    pw.flush();
    pw.close();
    HashMap<String, String> extra = new HashMap<String, String>();
    sLog.info("Overall penalty is " + getPerc(totalPenalty, minPenalty, maxPenalty) + "% (" + sDF.format(totalPenalty) + "/" + sDF.format(minPenalty) + ".." + sDF.format(maxPenalty) + ")");
    extra.put("Overall penalty", getPerc(totalPenalty, minPenalty, maxPenalty) + "% (" + sDF.format(totalPenalty) + "/" + sDF.format(minPenalty) + ".." + sDF.format(maxPenalty) + ")");
    extra.put("Overall available enrollment penalty", getPerc(totalPenalty, minAvEnrlPenalty, maxAvEnrlPenalty) + "% (" + sDF.format(totalPenalty) + "/" + sDF.format(minAvEnrlPenalty) + ".." + sDF.format(maxAvEnrlPenalty) + ")");
    if (onlineSelection.isUseStudentPrefPenalties()) {
        sLog.info("Overall preference penalty is " + getPerc(totalPrefPenalty, minPrefPenalty, maxPrefPenalty) + "% (" + sDF.format(totalPrefPenalty) + "/" + sDF.format(minPrefPenalty) + ".." + sDF.format(maxPrefPenalty) + ")");
        extra.put("Overall preference penalty", getPerc(totalPrefPenalty, minPrefPenalty, maxPrefPenalty) + "% (" + sDF.format(totalPrefPenalty) + "/" + sDF.format(minPrefPenalty) + ".." + sDF.format(maxPrefPenalty) + ")");
        extra.put("Overall preference available enrollment penalty", getPerc(totalPrefPenalty, minAvEnrlPrefPenalty, maxAvEnrlPrefPenalty) + "% (" + sDF.format(totalPrefPenalty) + "/" + sDF.format(minAvEnrlPrefPenalty) + ".." + sDF.format(maxAvEnrlPrefPenalty) + ")");
        extra.put("Average number of choices", sDF.format(((double) nrChoices) / nrCourseRequests) + " (" + nrChoices + "/" + nrCourseRequests + ")");
        extra.put("Average number of enrollments", sDF.format(((double) nrEnrollments) / nrCourseRequests) + " (" + nrEnrollments + "/" + nrCourseRequests + ")");
    }
    hook.setExtra(extra);
    return solution;
}