Student Sectioning: Student Scheduling Preferences

- added ability to define the following preferences on a student
  - modality preferences: require online, prefer online, discourage online, no preference
  - back-to-back preference: prefer back-to-backs, discourage back-to-backs, no preferences
  - class dates: optional class start date and class end date
- when a class is outside of the class dates or it is not online and online is required,
  - the class appears like it would be disabled (can be overridden by a reservation)
  - using Section.isEnabled(Student) which replaces Section.isEnabled()
- student schedule quality changes
  - penalisation can now consider the student and their preferences
    - it is now also possible to have a negative penalisation
  - added Modality criterion
    - weight StudentWeights.ModalityFactor, defaults to 0.0500
    - for students with prefer/discourage online,  there is a penalisation for classes with mismatching modality
  - BackToBack criterion now considers student's back-to-back preference
    - can return negative weight for a back-to-back conflict when back-to-backs are discouraged
- online sectioning: OnlineSection has now an ability to override class status (enabled/disabled)
  - classes that the student is enrolled in are considered always enabled (regardless of the student's preference)

src/org/cpsolver/coursett/model/TimeLocation.java

@@ -556,6 +556,19 @@ public int getFirstMeeting(int dayOfWeekOffset) {
         return iFirstMeeting;
     }
 
+    private Integer iLastMeeting = null;
+    public int getLastMeeting(int dayOfWeekOffset) {
+        if (iLastMeeting == null) {
+            int idx = -1;
+            while ((idx = getWeekCode().nextSetBit(1 + idx)) >= 0) {
+                int dow = (idx + dayOfWeekOffset) % 7;
+                if ((getDayCode() & Constants.DAY_CODES[dow]) != 0)
+                    iLastMeeting = idx;
+            }
+        }
+        return iLastMeeting;
+    }
+
     /** List dates when this time location meets. 
      * @return enumeration of dates of this time (indexes to the {@link TimeLocation#getWeekCode()} for matching days of the week)
      **/

src/org/cpsolver/studentsct/StudentSectioningModel.java

@@ -53,6 +53,8 @@
 import org.cpsolver.studentsct.model.Subpart;
 import org.cpsolver.studentsct.model.Unavailability;
 import org.cpsolver.studentsct.model.Request.RequestPriority;
+import org.cpsolver.studentsct.model.Student.BackToBackPreference;
+import org.cpsolver.studentsct.model.Student.ModalityPreference;
 import org.cpsolver.studentsct.model.Student.StudentPriority;
 import org.cpsolver.studentsct.reservation.Reservation;
 import org.cpsolver.studentsct.weights.PriorityStudentWeights;
@@ -109,6 +111,7 @@ public class StudentSectioningModel extends ModelWithContext<Request, Enrollment
     private boolean iKeepInitials;
     protected double iProjectedStudentWeight = 0.0100;
     private int iMaxDomainSize = -1; 
+    private int iDayOfWeekOffset = 0;
 
 
     /**
@@ -139,6 +142,7 @@ public StudentSectioningModel(DataProperties properties) {
         iKeepInitials = properties.getPropertyBoolean("Sectioning.KeepInitialAssignments", false);
         iStudentWeights = new PriorityStudentWeights(properties);
         iMaxDomainSize = properties.getPropertyInt("Sectioning.MaxDomainSize", iMaxDomainSize);
+        iDayOfWeekOffset = properties.getPropertyInt("DatePattern.DayOfWeekOffset", 0);
         if (properties.getPropertyBoolean("Sectioning.SectionLimit", true)) {
             SectionLimit sectionLimit = new SectionLimit(properties);
             addGlobalConstraint(sectionLimit);
@@ -481,8 +485,11 @@ public Map<String, String> getInfo(Assignment<Request, Enrollment> assignment) {
             if (confTravel > 0)
                 info.put("Schedule Quality: Travel time", sDoubleFormat.format(((double)confTravel) / getNrRealStudents(false)) + " mins per student (" + sDecimalFormat.format(confTravel / 60.0) + " hours total)");
             int confBtB = getStudentQuality().getTotalPenalty(StudentQuality.Type.BackToBack, assignment);
-            if (confBtB > 0)
+            if (confBtB != 0)
                 info.put("Schedule Quality: Back-to-back classes", sDoubleFormat.format(((double)confBtB) / getNrRealStudents(false)) + " per student (" + confBtB + ")");
+            int confMod = getStudentQuality().getTotalPenalty(StudentQuality.Type.Modality, assignment);
+            if (confMod > 0)
+                info.put("Schedule Quality: Online class preference", sDoubleFormat.format(((double)confMod) / getNrRealStudents(false)) + " per student (" + confMod + ")");
             int confWorkDay = getStudentQuality().getTotalPenalty(StudentQuality.Type.WorkDay, assignment);
             if (confWorkDay > 0)
                 info.put("Schedule Quality: Work day", sDoubleFormat.format(5.0 * confWorkDay / getNrRealStudents(false)) + " mins over " +
@@ -1018,6 +1025,74 @@ public Map<String, String> getExtendedInfo(Assignment<Request, Enrollment> assig
             if (share > 0)
                 info.put("Time overlapping conflicts", sDoubleFormat.format(5.0 * share / iStudents.size()) + " mins per student\n(" + sDoubleFormat.format(5.0 * crShare / iStudents.size()) + " between courses; " + sDoubleFormat.format(getTimeOverlaps().getTotalNrConflicts(assignment) / 12.0) + " hours total)");
         }
+        if (getStudentQuality() != null) {
+            int confBtB = getStudentQuality().getTotalPenalty(StudentQuality.Type.BackToBack, assignment);
+            if (confBtB != 0) {
+                int prefBtb = 0, discBtb = 0;
+                int prefStd = 0, discStd = 0;
+                int prefPairs = 0, discPairs = 0;
+                for (Student s: getStudents()) {
+                    if (s.isDummy() || s.getBackToBackPreference() == BackToBackPreference.NO_PREFERENCE) continue;
+                    int[] classesPerDay = new int[] {0, 0, 0, 0, 0, 0, 0};
+                    for (Request r: s.getRequests()) {
+                        Enrollment e = r.getAssignment(assignment);
+                        if (e == null || !e.isCourseRequest()) continue;
+                        for (Section x: e.getSections()) {
+                            if (x.getTime() != null)
+                                for (int i = 0; i < Constants.DAY_CODES.length; i++)
+                                    if ((x.getTime().getDayCode() & Constants.DAY_CODES[i]) != 0)
+                                        classesPerDay[i] ++;
+                        }
+                    }
+                    int max = 0;
+                    for (int c: classesPerDay)
+                        if (c > 1) max += c - 1;
+                    int btb = getStudentQuality().getContext(assignment).allPenalty(StudentQuality.Type.BackToBack, assignment, s);
+                    if (s.getBackToBackPreference() == BackToBackPreference.BTB_PREFERRED) {
+                        prefStd ++;
+                        prefBtb += btb;
+                        prefPairs += Math.max(btb, max);
+                    } else if (s.getBackToBackPreference() == BackToBackPreference.BTB_DISCOURAGED) {
+                        discStd ++;
+                        discBtb -= btb;
+                        discPairs += Math.max(btb, max);
+                    }
+                }
+                if (prefStd > 0)
+                    info.put("Schedule Quality: Back-to-back preferred", sDoubleFormat.format((100.0 * prefBtb) / prefPairs) + "% back-to-backs on average (" + prefBtb + "/" + prefPairs + " BTBs for " + prefStd + " students)");
+                if (discStd > 0)
+                    info.put("Schedule Quality: Back-to-back discouraged", sDoubleFormat.format(100.0 - (100.0 * discBtb) / discPairs) + "% non back-to-backs on average (" + discBtb + "/" + discPairs + " BTBs for " + discStd + " students)");
+            }
+            int confMod = getStudentQuality().getTotalPenalty(StudentQuality.Type.Modality, assignment);
+            if (confMod > 0) {
+                int prefOnl = 0, discOnl = 0;
+                int prefStd = 0, discStd = 0;
+                int prefCls = 0, discCls = 0;
+                for (Student s: getStudents()) {
+                    if (s.isDummy()) continue;
+                    if (s.isDummy() || s.getModalityPreference() == ModalityPreference.NO_PREFERENCE || s.getModalityPreference() == ModalityPreference.ONLINE_REQUIRED) continue;
+                    int classes = 0;
+                    for (Request r: s.getRequests()) {
+                        Enrollment e = r.getAssignment(assignment);
+                        if (e == null || !e.isCourseRequest()) continue;
+                        classes += e.getSections().size();
+                    }
+                    if (s.getModalityPreference() == ModalityPreference.ONLINE_PREFERRED) {
+                        prefStd ++;
+                        prefOnl += getStudentQuality().getContext(assignment).allPenalty(StudentQuality.Type.Modality, assignment, s);
+                        prefCls += classes;
+                    } else if (s.getModalityPreference() == ModalityPreference.ONILNE_DISCOURAGED) {
+                        discStd ++;
+                        discOnl += getStudentQuality().getContext(assignment).allPenalty(StudentQuality.Type.Modality, assignment, s);
+                        discCls += classes;
+                    }
+                }
+                if (prefStd > 0)
+                    info.put("Schedule Quality: Online preferred", sDoubleFormat.format(100.0 - (100.0 * prefOnl) / prefCls) + "% online classes on average (" + prefOnl + "/" + prefCls + " classes for " + prefStd + " students)");
+                if (discStd > 0)
+                    info.put("Schedule Quality: Online discouraged", sDoubleFormat.format(100.0 - (100.0 * discOnl) / discCls) + "% face-to-face classes on average (" + discOnl + "/" + discCls + " classes for " + discStd + " students)");
+            }
+        }
         /*
         info.put("Overall solution value", sDecimalFormat.format(total - dc - toc) + (dc == 0.0 && toc == 0.0 ? "" :
             " (" + (dc != 0.0 ? "distance: " + sDecimalFormat.format(dc): "") + (dc != 0.0 && toc != 0.0 ? ", " : "") + 
@@ -1406,6 +1481,12 @@ public double avg(double w1, double w2) {
      */
     public void setMaxDomainSize(int maxDomainSize) { iMaxDomainSize = maxDomainSize; }
 
+    public int getDayOfWeekOffset() { return iDayOfWeekOffset; }
+    public void setDayOfWeekOffset(int dayOfWeekOffset) {
+        iDayOfWeekOffset = dayOfWeekOffset;
+        if (iProperties != null)
+            iProperties.setProperty("DatePattern.DayOfWeekOffset", Integer.toString(dayOfWeekOffset));
+    }
 
     @Override
     public StudentSectioningModelContext createAssignmentContext(Assignment<Request, Enrollment> assignment) {

src/org/cpsolver/studentsct/StudentSectioningXMLLoader.java

@@ -32,6 +32,8 @@
 import org.cpsolver.studentsct.model.Offering;
 import org.cpsolver.studentsct.model.Request;
 import org.cpsolver.studentsct.model.Request.RequestPriority;
+import org.cpsolver.studentsct.model.Student.BackToBackPreference;
+import org.cpsolver.studentsct.model.Student.ModalityPreference;
 import org.cpsolver.studentsct.model.Student.StudentPriority;
 import org.cpsolver.studentsct.model.RequestGroup;
 import org.cpsolver.studentsct.model.Section;
@@ -983,6 +985,19 @@ protected Student loadStudent(Element studentEl, Map<Long, Offering> offeringTab
         String maxCredit = studentEl.attributeValue("maxCredit");
         if (maxCredit != null)
             student.setMaxCredit(Float.parseFloat(maxCredit));
+        String classFirstDate = studentEl.attributeValue("classFirstDate");
+        if (classFirstDate != null)
+            student.setClassFirstDate(Integer.parseInt(classFirstDate));
+        String classLastDate = studentEl.attributeValue("classLastDate");
+        if (classLastDate != null)
+            student.setClassLastDate(Integer.parseInt(classLastDate));
+        String modality = studentEl.attributeValue("modality");
+        if (modality != null)
+            student.setModalityPreference(ModalityPreference.valueOf(modality));
+        String btb = studentEl.attributeValue("btb");
+        if (btb != null)
+            student.setBackToBackPreference(BackToBackPreference.valueOf(btb));
+
         List<String[]> clasf = new ArrayList<String[]>();
         List<String[]> major = new ArrayList<String[]>();
         for (Iterator<?> j = studentEl.elementIterator(); j.hasNext();) {

src/org/cpsolver/studentsct/StudentSectioningXMLSaver.java

@@ -33,6 +33,8 @@
 import org.cpsolver.studentsct.model.RequestGroup;
 import org.cpsolver.studentsct.model.Section;
 import org.cpsolver.studentsct.model.Student;
+import org.cpsolver.studentsct.model.Student.BackToBackPreference;
+import org.cpsolver.studentsct.model.Student.ModalityPreference;
 import org.cpsolver.studentsct.model.Student.StudentPriority;
 import org.cpsolver.studentsct.model.StudentGroup;
 import org.cpsolver.studentsct.model.Subpart;
@@ -671,6 +673,14 @@ protected void saveStudent(Element studentEl, Student student) {
             studentEl.addAttribute("minCredit", String.valueOf(student.getMinCredit()));
         if (student.hasMaxCredit())
             studentEl.addAttribute("maxCredit", String.valueOf(student.getMaxCredit()));
+        if (student.getClassFirstDate() != null)
+            studentEl.addAttribute("classFirstDate", String.valueOf(student.getClassFirstDate()));
+        if (student.getClassLastDate() != null)
+            studentEl.addAttribute("classLastDate", String.valueOf(student.getClassLastDate()));
+        if (student.getModalityPreference() != null && student.getModalityPreference() != ModalityPreference.NO_PREFERENCE)
+            studentEl.addAttribute("modality", student.getModalityPreference().name());
+        if (student.getBackToBackPreference() != null && student.getBackToBackPreference() != BackToBackPreference.NO_PREFERENCE)
+            studentEl.addAttribute("btb", student.getBackToBackPreference().name());
         if (iSaveStudentInfo) {
             for (AreaClassificationMajor acm : student.getAreaClassificationMajors()) {
                 Element acmEl = studentEl.addElement("acm");

src/org/cpsolver/studentsct/constraint/DisabledSections.java

@@ -72,7 +72,7 @@ public boolean inConflict(Assignment<Request, Enrollment> assignment, Enrollment
         boolean hasDisabledSection = false;
         // check all sections of the given enrollment
         for (Section section: enrollment.getSections())
-            if (!section.isEnabled()) {
+            if (!section.isEnabled(enrollment.getStudent())) {
                 hasDisabledSection = true;
                 break;
             }