001    package net.sf.cpsolver.coursett.model;
002    
003    import java.util.ArrayList;
004    import java.util.BitSet;
005    import java.util.Collection;
006    import java.util.HashSet;
007    import java.util.HashMap;
008    import java.util.List;
009    import java.util.Locale;
010    import java.util.Map;
011    import java.util.Set;
012    
013    import net.sf.cpsolver.coursett.Constants;
014    import net.sf.cpsolver.coursett.constraint.ClassLimitConstraint;
015    import net.sf.cpsolver.coursett.constraint.DepartmentSpreadConstraint;
016    import net.sf.cpsolver.coursett.constraint.GroupConstraint;
017    import net.sf.cpsolver.coursett.constraint.InstructorConstraint;
018    import net.sf.cpsolver.coursett.constraint.JenrlConstraint;
019    import net.sf.cpsolver.coursett.constraint.FlexibleConstraint;
020    import net.sf.cpsolver.coursett.constraint.RoomConstraint;
021    import net.sf.cpsolver.coursett.constraint.SpreadConstraint;
022    import net.sf.cpsolver.coursett.constraint.WeakeningConstraint;
023    import net.sf.cpsolver.coursett.criteria.BackToBackInstructorPreferences;
024    import net.sf.cpsolver.coursett.criteria.BrokenTimePatterns;
025    import net.sf.cpsolver.coursett.criteria.DepartmentBalancingPenalty;
026    import net.sf.cpsolver.coursett.criteria.DistributionPreferences;
027    import net.sf.cpsolver.coursett.criteria.FlexibleConstraintCriterion;
028    import net.sf.cpsolver.coursett.criteria.Perturbations;
029    import net.sf.cpsolver.coursett.criteria.RoomPreferences;
030    import net.sf.cpsolver.coursett.criteria.RoomViolations;
031    import net.sf.cpsolver.coursett.criteria.SameSubpartBalancingPenalty;
032    import net.sf.cpsolver.coursett.criteria.StudentCommittedConflict;
033    import net.sf.cpsolver.coursett.criteria.StudentConflict;
034    import net.sf.cpsolver.coursett.criteria.StudentDistanceConflict;
035    import net.sf.cpsolver.coursett.criteria.StudentHardConflict;
036    import net.sf.cpsolver.coursett.criteria.StudentOverlapConflict;
037    import net.sf.cpsolver.coursett.criteria.TimePreferences;
038    import net.sf.cpsolver.coursett.criteria.TimeViolations;
039    import net.sf.cpsolver.coursett.criteria.TooBigRooms;
040    import net.sf.cpsolver.coursett.criteria.UselessHalfHours;
041    import net.sf.cpsolver.coursett.criteria.placement.AssignmentCount;
042    import net.sf.cpsolver.coursett.criteria.placement.DeltaTimePreference;
043    import net.sf.cpsolver.coursett.criteria.placement.HardConflicts;
044    import net.sf.cpsolver.coursett.criteria.placement.PotentialHardConflicts;
045    import net.sf.cpsolver.coursett.criteria.placement.WeightedHardConflicts;
046    import net.sf.cpsolver.ifs.constant.ConstantModel;
047    import net.sf.cpsolver.ifs.criteria.Criterion;
048    import net.sf.cpsolver.ifs.model.Constraint;
049    import net.sf.cpsolver.ifs.model.GlobalConstraint;
050    import net.sf.cpsolver.ifs.util.DataProperties;
051    import net.sf.cpsolver.ifs.util.DistanceMetric;
052    
053    /**
054     * Timetable model.
055     * 
056     * @version CourseTT 1.2 (University Course Timetabling)<br>
057     *          Copyright (C) 2006 - 2010 Tomas Muller<br>
058     *          <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
059     *          <a href="http://muller.unitime.org">http://muller.unitime.org</a><br>
060     * <br>
061     *          This library is free software; you can redistribute it and/or modify
062     *          it under the terms of the GNU Lesser General Public License as
063     *          published by the Free Software Foundation; either version 3 of the
064     *          License, or (at your option) any later version. <br>
065     * <br>
066     *          This library is distributed in the hope that it will be useful, but
067     *          WITHOUT ANY WARRANTY; without even the implied warranty of
068     *          MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
069     *          Lesser General Public License for more details. <br>
070     * <br>
071     *          You should have received a copy of the GNU Lesser General Public
072     *          License along with this library; if not see
073     *          <a href='http://www.gnu.org/licenses/'>http://www.gnu.org/licenses/</a>.
074     */
075    
076    public class TimetableModel extends ConstantModel<Lecture, Placement> {
077        private static org.apache.log4j.Logger sLogger = org.apache.log4j.Logger.getLogger(TimetableModel.class);
078        private static java.text.DecimalFormat sDoubleFormat = new java.text.DecimalFormat("0.00",
079                new java.text.DecimalFormatSymbols(Locale.US));
080    
081        private List<InstructorConstraint> iInstructorConstraints = new ArrayList<InstructorConstraint>();
082        private List<JenrlConstraint> iJenrlConstraints = new ArrayList<JenrlConstraint>();
083        private List<RoomConstraint> iRoomConstraints = new ArrayList<RoomConstraint>();
084        private List<DepartmentSpreadConstraint> iDepartmentSpreadConstraints = new ArrayList<DepartmentSpreadConstraint>();
085        private List<SpreadConstraint> iSpreadConstraints = new ArrayList<SpreadConstraint>();
086        private List<GroupConstraint> iGroupConstraints = new ArrayList<GroupConstraint>();
087        private List<ClassLimitConstraint> iClassLimitConstraints = new ArrayList<ClassLimitConstraint>();
088        private List<FlexibleConstraint> iFlexibleConstraints = new ArrayList<FlexibleConstraint>();
089        private DataProperties iProperties = null;
090        private int iYear = -1;
091        private List<BitSet> iWeeks = null;
092    
093        private HashSet<Student> iAllStudents = new HashSet<Student>();
094        
095        private DistanceMetric iDistanceMetric = null;
096    
097    
098        public TimetableModel(DataProperties properties) {
099            super();
100            iProperties = properties;
101            iDistanceMetric = new DistanceMetric(properties);
102            if (properties.getPropertyBoolean("OnFlySectioning.Enabled", false))
103                addModelListener(new OnFlySectioning(this));
104            String criteria = properties.getProperty("General.Criteria",
105                    // Objectives
106                    StudentConflict.class.getName() + ";" +
107                    StudentDistanceConflict.class.getName() + ";" +
108                    StudentHardConflict.class.getName() + ";" +
109                    StudentCommittedConflict.class.getName() + ";" +
110                    StudentOverlapConflict.class.getName() + ";" +
111                    UselessHalfHours.class.getName() + ";" +
112                    BrokenTimePatterns.class.getName() + ";" +
113                    TooBigRooms.class.getName() + ";" +
114                    TimePreferences.class.getName() + ";" +
115                    RoomPreferences.class.getName() + ";" +
116                    DistributionPreferences.class.getName() + ";" +
117                    SameSubpartBalancingPenalty.class.getName() + ";" +
118                    DepartmentBalancingPenalty.class.getName() + ";" +
119                    BackToBackInstructorPreferences.class.getName() + ";" +
120                    Perturbations.class.getName() + ";" +
121                    // Additional placement selection criteria
122                    AssignmentCount.class.getName() + ";" +
123                    DeltaTimePreference.class.getName() + ";" +
124                    HardConflicts.class.getName() + ";" +
125                    PotentialHardConflicts.class.getName() + ";" +
126                    FlexibleConstraintCriterion.class.getName() + ";" +
127                    WeightedHardConflicts.class.getName());                
128            // Interactive mode -- count time / room violations
129            if (properties.getPropertyBoolean("General.InteractiveMode", false))
130                criteria += ";" + TimeViolations.class.getName() + ";" + RoomViolations.class.getName();
131            // Additional (custom) criteria
132            criteria += ";" + properties.getProperty("General.AdditionalCriteria", "");
133            for (String criterion: criteria.split("\\;")) {
134                if (criterion == null || criterion.isEmpty()) continue;
135                try {
136                    @SuppressWarnings("unchecked")
137                    Class<Criterion<Lecture, Placement>> clazz = (Class<Criterion<Lecture, Placement>>)Class.forName(criterion);
138                    addCriterion(clazz.newInstance());
139                } catch (Exception e) {
140                    sLogger.error("Unable to use " + criterion + ": " + e.getMessage());
141                }
142            }
143        }
144    
145        public DistanceMetric getDistanceMetric() {
146            return iDistanceMetric;
147        }
148    
149        public DataProperties getProperties() {
150            return iProperties;
151        }
152    
153        /**
154         * Student final sectioning (switching students between sections of the same
155         * class in order to minimize overall number of student conflicts)
156         */
157        public void switchStudents() {
158            FinalSectioning sect = new FinalSectioning(this);
159            sect.run();
160        }
161    
162        @Override
163        public String toString() {
164            return "TimetableModel{" + "\n  super=" + super.toString()
165                    + "\n  studentConflicts=" + sDoubleFormat.format(getCriterion(StudentConflict.class).getValue())
166                    + "\n  roomPreferences=" + sDoubleFormat.format(getCriterion(RoomPreferences.class).getValue())
167                    + "\n  timePreferences=" + sDoubleFormat.format(getCriterion(TimePreferences.class).getValue())
168                    + "\n  groupConstraintPreferences=" + sDoubleFormat.format(getCriterion(DistributionPreferences.class).getValue())
169                    + "\n}";
170        }
171    
172        public Map<String, String> getBounds() {
173            Map<String, String> ret = new HashMap<String, String>();
174            ret.put("Room preferences min", "" + getCriterion(RoomPreferences.class).getBounds()[0]);
175            ret.put("Room preferences max", "" + getCriterion(RoomPreferences.class).getBounds()[1]);
176            ret.put("Time preferences min", "" + getCriterion(TimePreferences.class).getBounds()[0]);
177            ret.put("Time preferences max", "" + getCriterion(TimePreferences.class).getBounds()[1]);
178            ret.put("Distribution preferences min", "" + getCriterion(DistributionPreferences.class).getBounds()[0]);
179            ret.put("Distribution preferences max", "" + getCriterion(DistributionPreferences.class).getBounds()[1]);
180            if (getProperties().getPropertyBoolean("General.UseDistanceConstraints", false)) {
181                ret.put("Back-to-back instructor preferences max", "" + getCriterion(BackToBackInstructorPreferences.class).getBounds()[1]);
182            }
183            ret.put("Too big rooms max", "" + getCriterion(TooBigRooms.class).getBounds()[0]);
184            ret.put("Useless half-hours", "" + getCriterion(UselessHalfHours.class).getBounds()[0]);
185            return ret;
186        }
187    
188        /** Global info */
189        @Override
190        public Map<String, String> getInfo() {
191            Map<String, String> ret = super.getInfo();
192            ret.put("Memory usage", getMem());
193            
194            Criterion<Lecture, Placement> rp = getCriterion(RoomPreferences.class);
195            Criterion<Lecture, Placement> rv = getCriterion(RoomViolations.class);
196            ret.put("Room preferences", getPerc(rp.getValue(), rp.getBounds()[0], rp.getBounds()[1]) + "% (" + Math.round(rp.getValue()) + ")"
197                    + (rv != null && rv.getValue() >= 0.5 ? " [hard:" + Math.round(rv.getValue()) + "]" : ""));
198            
199            Criterion<Lecture, Placement> tp = getCriterion(TimePreferences.class);
200            Criterion<Lecture, Placement> tv = getCriterion(TimeViolations.class);
201            ret.put("Time preferences", getPerc(tp.getValue(), tp.getBounds()[0], tp.getBounds()[1]) + "% (" + sDoubleFormat.format(tp.getValue()) + ")"
202                    + (tv != null && tv.getValue() >= 0.5 ? " [hard:" + Math.round(tv.getValue()) + "]" : ""));
203    
204            Criterion<Lecture, Placement> dp = getCriterion(DistributionPreferences.class);
205            ret.put("Distribution preferences", getPerc(dp.getValue(), dp.getBounds()[0], dp.getBounds()[1]) + "% (" + sDoubleFormat.format(dp.getValue()) + ")");
206            
207            Criterion<Lecture, Placement> sc = getCriterion(StudentConflict.class);
208            Criterion<Lecture, Placement> shc = getCriterion(StudentHardConflict.class);
209            Criterion<Lecture, Placement> sdc = getCriterion(StudentDistanceConflict.class);
210            Criterion<Lecture, Placement> scc = getCriterion(StudentCommittedConflict.class);
211            ret.put("Student conflicts", Math.round(scc.getValue() + sc.getValue()) +
212                    " [committed:" + Math.round(scc.getValue()) +
213                    ", distance:" + Math.round(sdc.getValue()) +
214                    ", hard:" + Math.round(shc.getValue()) + "]");
215            
216            if (!getSpreadConstraints().isEmpty()) {
217                Criterion<Lecture, Placement> ip = getCriterion(BackToBackInstructorPreferences.class);
218                ret.put("Back-to-back instructor preferences", getPerc(ip.getValue(), ip.getBounds()[0], ip.getBounds()[1]) + "% (" + Math.round(ip.getValue()) + ")");
219            }
220    
221            if (!getDepartmentSpreadConstraints().isEmpty()) {
222                Criterion<Lecture, Placement> dbp = getCriterion(DepartmentBalancingPenalty.class);
223                ret.put("Department balancing penalty", sDoubleFormat.format(dbp.getValue()));
224            }
225            
226            Criterion<Lecture, Placement> sbp = getCriterion(SameSubpartBalancingPenalty.class);
227            ret.put("Same subpart balancing penalty", sDoubleFormat.format(sbp.getValue()));
228            
229            Criterion<Lecture, Placement> tbr = getCriterion(TooBigRooms.class);
230            ret.put("Too big rooms", getPercRev(tbr.getValue(), tbr.getBounds()[1], tbr.getBounds()[0]) + "% (" + Math.round(tbr.getValue()) + ")");
231            
232            Criterion<Lecture, Placement> uh = getCriterion(UselessHalfHours.class);
233            Criterion<Lecture, Placement> bt = getCriterion(BrokenTimePatterns.class);
234    
235            ret.put("Useless half-hours", getPercRev(uh.getValue() + bt.getValue(), 0, Constants.sPreferenceLevelStronglyDiscouraged * bt.getBounds()[0]) +
236                    "% (" + Math.round(uh.getValue()) + " + " + Math.round(bt.getValue()) + ")");
237            return ret;
238        }
239    
240        @Override
241        public Map<String, String> getInfo(Collection<Lecture> variables) {
242            Map<String, String> ret = super.getInfo(variables);
243            
244            ret.put("Memory usage", getMem());
245            
246            Criterion<Lecture, Placement> rp = getCriterion(RoomPreferences.class);
247            ret.put("Room preferences", getPerc(rp.getValue(variables), rp.getBounds(variables)[0], rp.getBounds(variables)[1]) + "% (" + Math.round(rp.getValue(variables)) + ")");
248            
249            Criterion<Lecture, Placement> tp = getCriterion(TimePreferences.class);
250            ret.put("Time preferences", getPerc(tp.getValue(variables), tp.getBounds(variables)[0], tp.getBounds(variables)[1]) + "% (" + sDoubleFormat.format(tp.getValue(variables)) + ")"); 
251    
252            Criterion<Lecture, Placement> dp = getCriterion(DistributionPreferences.class);
253            ret.put("Distribution preferences", getPerc(dp.getValue(variables), dp.getBounds(variables)[0], dp.getBounds(variables)[1]) + "% (" + sDoubleFormat.format(dp.getValue(variables)) + ")");
254            
255            Criterion<Lecture, Placement> sc = getCriterion(StudentConflict.class);
256            Criterion<Lecture, Placement> shc = getCriterion(StudentHardConflict.class);
257            Criterion<Lecture, Placement> sdc = getCriterion(StudentDistanceConflict.class);
258            Criterion<Lecture, Placement> scc = getCriterion(StudentCommittedConflict.class);
259            ret.put("Student conflicts", Math.round(scc.getValue(variables) + sc.getValue(variables)) +
260                    " [committed:" + Math.round(scc.getValue(variables)) +
261                    ", distance:" + Math.round(sdc.getValue(variables)) +
262                    ", hard:" + Math.round(shc.getValue(variables)) + "]");
263            
264            if (!getSpreadConstraints().isEmpty()) {
265                Criterion<Lecture, Placement> ip = getCriterion(BackToBackInstructorPreferences.class);
266                ret.put("Back-to-back instructor preferences", getPerc(ip.getValue(variables), ip.getBounds(variables)[0], ip.getBounds(variables)[1]) + "% (" + Math.round(ip.getValue(variables)) + ")");
267            }
268    
269            if (!getDepartmentSpreadConstraints().isEmpty()) {
270                Criterion<Lecture, Placement> dbp = getCriterion(DepartmentBalancingPenalty.class);
271                ret.put("Department balancing penalty", sDoubleFormat.format(dbp.getValue(variables)));
272            }
273            
274            Criterion<Lecture, Placement> sbp = getCriterion(SameSubpartBalancingPenalty.class);
275            ret.put("Same subpart balancing penalty", sDoubleFormat.format(sbp.getValue(variables)));
276            
277            Criterion<Lecture, Placement> tbr = getCriterion(TooBigRooms.class);
278            ret.put("Too big rooms", getPercRev(tbr.getValue(variables), tbr.getBounds(variables)[1], tbr.getBounds(variables)[0]) + "% (" + Math.round(tbr.getValue(variables)) + ")");
279            
280            Criterion<Lecture, Placement> uh = getCriterion(UselessHalfHours.class);
281            Criterion<Lecture, Placement> bt = getCriterion(BrokenTimePatterns.class);
282    
283            ret.put("Useless half-hours", getPercRev(uh.getValue(variables) + bt.getValue(variables), 0, Constants.sPreferenceLevelStronglyDiscouraged * bt.getBounds(variables)[0]) +
284                    "% (" + Math.round(uh.getValue(variables)) + " + " + Math.round(bt.getValue(variables)) + ")");
285            return ret;
286        }
287    
288        @Override
289        public void addConstraint(Constraint<Lecture, Placement> constraint) {
290            super.addConstraint(constraint);
291            if (constraint instanceof InstructorConstraint) {
292                iInstructorConstraints.add((InstructorConstraint) constraint);
293            } else if (constraint instanceof JenrlConstraint) {
294                iJenrlConstraints.add((JenrlConstraint) constraint);
295            } else if (constraint instanceof RoomConstraint) {
296                iRoomConstraints.add((RoomConstraint) constraint);
297            } else if (constraint instanceof DepartmentSpreadConstraint) {
298                iDepartmentSpreadConstraints.add((DepartmentSpreadConstraint) constraint);
299            } else if (constraint instanceof SpreadConstraint) {
300                iSpreadConstraints.add((SpreadConstraint) constraint);
301            } else if (constraint instanceof ClassLimitConstraint) {
302                iClassLimitConstraints.add((ClassLimitConstraint) constraint);
303            } else if (constraint instanceof GroupConstraint) {
304                iGroupConstraints.add((GroupConstraint) constraint);
305            } else if (constraint instanceof FlexibleConstraint) {
306                iFlexibleConstraints.add((FlexibleConstraint) constraint);
307            }
308        }
309    
310        @Override
311        public void removeConstraint(Constraint<Lecture, Placement> constraint) {
312            super.removeConstraint(constraint);
313            if (constraint instanceof InstructorConstraint) {
314                iInstructorConstraints.remove(constraint);
315            } else if (constraint instanceof JenrlConstraint) {
316                iJenrlConstraints.remove(constraint);
317            } else if (constraint instanceof RoomConstraint) {
318                iRoomConstraints.remove(constraint);
319            } else if (constraint instanceof DepartmentSpreadConstraint) {
320                iDepartmentSpreadConstraints.remove(constraint);
321            } else if (constraint instanceof SpreadConstraint) {
322                iSpreadConstraints.remove(constraint);
323            } else if (constraint instanceof ClassLimitConstraint) {
324                iClassLimitConstraints.remove(constraint);
325            } else if (constraint instanceof GroupConstraint) {
326                iGroupConstraints.remove(constraint);
327            } else if (constraint instanceof FlexibleConstraint) {
328                iFlexibleConstraints.remove(constraint);
329            }
330        }
331    
332        /** The list of all instructor constraints */
333        public List<InstructorConstraint> getInstructorConstraints() {
334            return iInstructorConstraints;
335        }
336    
337        /** The list of all group constraints */
338        public List<GroupConstraint> getGroupConstraints() {
339            return iGroupConstraints;
340        }
341    
342        /** The list of all jenrl constraints */
343        public List<JenrlConstraint> getJenrlConstraints() {
344            return iJenrlConstraints;
345        }
346    
347        /** The list of all room constraints */
348        public List<RoomConstraint> getRoomConstraints() {
349            return iRoomConstraints;
350        }
351    
352        /** The list of all departmental spread constraints */
353        public List<DepartmentSpreadConstraint> getDepartmentSpreadConstraints() {
354            return iDepartmentSpreadConstraints;
355        }
356    
357        public List<SpreadConstraint> getSpreadConstraints() {
358            return iSpreadConstraints;
359        }
360    
361        public List<ClassLimitConstraint> getClassLimitConstraints() {
362            return iClassLimitConstraints;
363        }
364        
365        public List<FlexibleConstraint> getFlexibleConstraints() {
366            return iFlexibleConstraints;
367        }
368        
369        @Override
370        public double getTotalValue() {
371            double ret = 0;
372            for (Criterion<Lecture, Placement> criterion: getCriteria())
373                ret += criterion.getWeightedValue();
374            return ret;
375        }
376    
377        @Override
378        public double getTotalValue(Collection<Lecture> variables) {
379            double ret = 0;
380            for (Criterion<Lecture, Placement> criterion: getCriteria())
381                ret += criterion.getWeightedValue(variables);
382            return ret;
383        }
384    
385        public int getYear() {
386            return iYear;
387        }
388    
389        public void setYear(int year) {
390            iYear = year;
391        }
392    
393        public Set<Student> getAllStudents() {
394            return iAllStudents;
395        }
396    
397        public void addStudent(Student student) {
398            iAllStudents.add(student);
399        }
400    
401        public void removeStudent(Student student) {
402            iAllStudents.remove(student);
403        }
404    
405        /**
406         * Returns amount of allocated memory.
407         * 
408         * @return amount of allocated memory to be written in the log
409         */
410        public static synchronized String getMem() {
411            Runtime rt = Runtime.getRuntime();
412            return sDoubleFormat.format(((double) (rt.totalMemory() - rt.freeMemory())) / 1048576) + "M";
413        }
414        
415        
416        /**
417         * Returns the set of conflicting variables with this value, if it is
418         * assigned to its variable. Conflicts with constraints that implement
419         * {@link WeakeningConstraint} are ignored.
420         */
421        public Set<Placement> conflictValuesSkipWeakeningConstraints(Placement value) {
422            Set<Placement> conflictValues = new HashSet<Placement>();
423            for (Constraint<Lecture, Placement> constraint : value.variable().hardConstraints()) {
424                if (constraint instanceof WeakeningConstraint) continue;
425                constraint.computeConflicts(value, conflictValues);
426            }
427            for (GlobalConstraint<Lecture, Placement> constraint : globalConstraints()) {
428                if (constraint instanceof WeakeningConstraint) continue;
429                constraint.computeConflicts(value, conflictValues);
430            }
431            return conflictValues;
432        }
433        
434        
435        /**
436         * Weaken all weakening constraint so that the given value can be assigned without
437         * them creating a conflict using {@link WeakeningConstraint#weaken(Placement)}.
438         * This method is handy for instance when an existing solution is being loaded
439         * into the solver.
440         */
441        public void weaken(Placement value) {
442            for (Constraint<Lecture, Placement> constraint : value.variable().hardConstraints()) {
443                if (constraint instanceof WeakeningConstraint)
444                    ((WeakeningConstraint)constraint).weaken(value);
445            }
446            for (GlobalConstraint<Lecture, Placement> constraint : globalConstraints()) {
447                if (constraint instanceof WeakeningConstraint)
448                    ((WeakeningConstraint)constraint).weaken(value);
449            }
450        }
451        
452        /**
453         * The method creates date patterns (bitsets) which represent the weeks of a
454         * semester.
455         *      
456         * @return a list of BitSets which represents the weeks of a semester.
457         */
458        public List<BitSet> getWeeks() {
459            if (iWeeks == null) {
460                String defaultDatePattern = getProperties().getProperty("DatePattern.CustomDatePattern", null);
461                if (defaultDatePattern == null){                
462                    defaultDatePattern = getProperties().getProperty("DatePattern.Default");
463                }
464                if (defaultDatePattern == null) return null;
465                
466                // Create default date pattern
467                BitSet fullTerm = new BitSet(defaultDatePattern.length());
468                for (int i = 0; i < defaultDatePattern.length(); i++) {
469                    if (defaultDatePattern.charAt(i) == 49) {
470                        fullTerm.set(i);
471                    }
472                }
473                
474                // Cut date pattern into weeks (every week contains 7 positive bits)
475                iWeeks = new ArrayList<BitSet>();
476                int cnt = 0;
477                for (int i = 0; i < fullTerm.length(); i++) {
478                    if (fullTerm.get(i)) {
479                        int w = (cnt++) / 7;
480                        if (iWeeks.size() == w) {
481                            iWeeks.add(new BitSet(fullTerm.length()));
482                        }
483                        iWeeks.get(w).set(i);
484                    }
485                }
486            }
487            return iWeeks;            
488        }
489    }