Examples with Constraint org.cpsolver.ifs.model.Constraint used on opensource projects

Example 11 with Constraint

use of org.cpsolver.ifs.model.Constraint in project cpsolver by UniTime.

the class CSPModel method buildBinaryConstraintGraph.

private void buildBinaryConstraintGraph(Random rnd) {
    int numberOfAllPairs = variables().size() * (variables().size() - 1) / 2;
    CSPVariable[][] allPairs = new CSPVariable[numberOfAllPairs][];
    int idx = 0;
    for (CSPVariable v1 : variables()) {
        for (CSPVariable v2 : variables()) {
            if (v1.getId() >= v2.getId())
                continue;
            allPairs[idx++] = new CSPVariable[] { v1, v2 };
        }
    }
    idx = 0;
    for (Iterator<Constraint<CSPVariable, CSPValue>> i = constraints().iterator(); i.hasNext(); ) {
        CSPBinaryConstraint c = (CSPBinaryConstraint) i.next();
        swap(allPairs, idx, idx + (int) (rnd.nextDouble() * (numberOfAllPairs - idx)));
        c.addVariable(allPairs[idx][0]);
        c.addVariable(allPairs[idx][1]);
        c.init(rnd);
        idx++;
    }
}

Example 12 with Constraint

use of org.cpsolver.ifs.model.Constraint in project cpsolver by UniTime.

the class GroupConstraint method forwardCheck.

public boolean forwardCheck(Assignment<Lecture, Placement> assignment, Placement value, Set<GroupConstraint> ignore, int depth) {
    try {
        if (depth < 0)
            return true;
        ignore.add(this);
        int neededSize = value.variable().maxRoomUse();
        for (Lecture lecture : variables()) {
            // Skip this lecture
            if (lecture.equals(value.variable()))
                continue;
            Placement current = assignment.getValue(lecture);
            if (current != null) {
                // Has assignment, check whether it is conflicting
                if (isSatisfiedPair(assignment, value, current)) {
                    // Increase needed size if the assignment is of the same room and overlapping in time
                    if (canShareRoom() && sameRoomAndOverlaps(value, current)) {
                        neededSize += lecture.maxRoomUse();
                    }
                    continue;
                }
                return false;
            }
            // Look for supporting assignments assignment
            boolean shareRoomAndOverlaps = canShareRoom();
            Placement support = null;
            int nrSupports = 0;
            if (lecture.nrValues() >= iForwardCheckMaxDomainSize) {
                // ignore variables with large domains
                return true;
            }
            List<Placement> values = lecture.values(assignment);
            if (values.isEmpty()) {
                // ignore variables with empty domain
                return true;
            }
            for (Placement other : lecture.values(assignment)) {
                if (nrSupports < 2) {
                    if (isSatisfiedPair(assignment, value, other)) {
                        if (support == null)
                            support = other;
                        nrSupports++;
                        if (shareRoomAndOverlaps && !sameRoomAndOverlaps(value, other))
                            shareRoomAndOverlaps = false;
                    }
                } else if (shareRoomAndOverlaps && !sameRoomAndOverlaps(value, other) && isSatisfiedPair(assignment, value, other)) {
                    shareRoomAndOverlaps = false;
                }
                if (nrSupports > 1 && !shareRoomAndOverlaps)
                    break;
            }
            // No supporting assignment -> fail
            if (nrSupports == 0) {
                // other class cannot be assigned with this value
                return false;
            }
            // Increase needed size if all supporters are of the same room and in overlapping times
            if (shareRoomAndOverlaps) {
                neededSize += lecture.maxRoomUse();
            }
            // Only one supporter -> propagate the new assignment over other hard constraints of the lecture
            if (nrSupports == 1) {
                for (Constraint<Lecture, Placement> other : lecture.hardConstraints()) {
                    if (other instanceof WeakeningConstraint)
                        continue;
                    if (other instanceof GroupConstraint) {
                        GroupConstraint gc = (GroupConstraint) other;
                        if (depth > 0 && !ignore.contains(gc) && !gc.forwardCheck(assignment, support, ignore, depth - 1))
                            return false;
                    } else {
                        if (other.inConflict(assignment, support))
                            return false;
                    }
                }
                for (GlobalConstraint<Lecture, Placement> other : getModel().globalConstraints()) {
                    if (other instanceof WeakeningConstraint)
                        continue;
                    if (other.inConflict(assignment, support))
                        return false;
                }
            }
        }
        if (canShareRoom() && neededSize > value.getRoomSize()) {
            // room is too small to fit all meet with classes
            return false;
        }
        return true;
    } finally {
        ignore.remove(this);
    }
}

Example 13 with Constraint

use of org.cpsolver.ifs.model.Constraint in project cpsolver by UniTime.

the class GroupConstraint method forwardCheck.

public void forwardCheck(Assignment<Lecture, Placement> assignment, Placement value, Set<Placement> conflicts, Set<GroupConstraint> ignore, int depth) {
    try {
        if (depth < 0)
            return;
        ignore.add(this);
        List<Placement> neededSize = null;
        for (Lecture lecture : variables()) {
            // already conflicting
            if (conflicts.contains(value))
                break;
            // Skip this lecture
            if (lecture.equals(value.variable()))
                continue;
            Placement current = assignment.getValue(lecture);
            if (current != null) {
                // Has assignment, check whether it is conflicting
                if (isSatisfiedPair(assignment, value, current)) {
                    // Increase needed size if the assignment is of the same room and overlapping in time
                    if (canShareRoom() && sameRoomAndOverlaps(value, current)) {
                        if (neededSize == null)
                            neededSize = new ArrayList<Placement>();
                        neededSize.add(current);
                    }
                    continue;
                }
                conflicts.add(current);
            }
            // Look for supporting assignments assignment
            boolean shareRoomAndOverlaps = canShareRoom();
            Placement support = null;
            int nrSupports = 0;
            if (lecture.nrValues() >= iForwardCheckMaxDomainSize) {
                // ignore variables with large domains
                return;
            }
            List<Placement> values = lecture.values(assignment);
            if (values.isEmpty()) {
                // ignore variables with empty domain
                return;
            }
            for (Placement other : values) {
                if (nrSupports < 2) {
                    if (isSatisfiedPair(assignment, value, other)) {
                        if (support == null)
                            support = other;
                        nrSupports++;
                        if (shareRoomAndOverlaps && !sameRoomAndOverlaps(value, other))
                            shareRoomAndOverlaps = false;
                    }
                } else if (shareRoomAndOverlaps && !sameRoomAndOverlaps(value, other) && isSatisfiedPair(assignment, value, other)) {
                    shareRoomAndOverlaps = false;
                }
                if (nrSupports > 1 && !shareRoomAndOverlaps)
                    break;
            }
            // No supporting assignment -> fail
            if (nrSupports == 0) {
                // other class cannot be assigned with this value
                conflicts.add(value);
                return;
            }
            // Increase needed size if all supporters are of the same room and in overlapping times
            if (shareRoomAndOverlaps && support != null) {
                if (neededSize == null)
                    neededSize = new ArrayList<Placement>();
                neededSize.add(support);
            }
            // Only one supporter -> propagate the new assignment over other hard constraints of the lecture
            if (nrSupports == 1) {
                for (Constraint<Lecture, Placement> other : lecture.hardConstraints()) {
                    if (other instanceof WeakeningConstraint)
                        continue;
                    if (other instanceof GroupConstraint) {
                        GroupConstraint gc = (GroupConstraint) other;
                        if (depth > 0 && !ignore.contains(gc))
                            gc.forwardCheck(assignment, support, conflicts, ignore, depth - 1);
                    } else {
                        other.computeConflicts(assignment, support, conflicts);
                    }
                }
                for (GlobalConstraint<Lecture, Placement> other : getModel().globalConstraints()) {
                    if (other instanceof WeakeningConstraint)
                        continue;
                    other.computeConflicts(assignment, support, conflicts);
                }
                if (conflicts.contains(support))
                    conflicts.add(value);
            }
        }
        if (canShareRoom() && neededSize != null) {
            if (value.getRoomLocations() != null) {
                for (RoomLocation room : value.getRoomLocations()) if (room.getRoomConstraint() != null && !room.getRoomConstraint().checkRoomSize(value, neededSize)) {
                    // room is too small to fit all meet with classes
                    conflicts.add(value);
                }
            } else if (value.getRoomLocation() != null) {
                RoomLocation room = value.getRoomLocation();
                if (room.getRoomConstraint() != null && !room.getRoomConstraint().checkRoomSize(value, neededSize)) {
                    // room is too small to fit all meet with classes
                    conflicts.add(value);
                }
            }
        }
    } finally {
        ignore.remove(this);
    }
}

Example 14 with Constraint

use of org.cpsolver.ifs.model.Constraint in project cpsolver by UniTime.

the class TimetableModel method saveAsXML.

public void saveAsXML(DataProperties cfg, boolean gen, Solution<Activity, Location> solution, Assignment<Activity, Location> assignment, File outFile) throws IOException {
    outFile.getParentFile().mkdirs();
    sLogger.debug("Writting XML data to:" + outFile);
    Document document = DocumentHelper.createDocument();
    document.addComment("Interactive Timetabling - University Timetable Generator (version 2.0)");
    if (assignment == null && solution != null)
        assignment = solution.getAssignment();
    if (assignment == null)
        assignment = new DefaultSingleAssignment<Activity, Location>();
    if (!assignedVariables(assignment).isEmpty()) {
        StringBuffer comments = new StringBuffer("Solution Info:\n");
        Map<String, String> solutionInfo = (solution == null ? getInfo(assignment) : solution.getInfo());
        for (String key : new TreeSet<String>(solutionInfo.keySet())) {
            String value = solutionInfo.get(key);
            comments.append("    " + key + ": " + value + "\n");
        }
        document.addComment(comments.toString());
    }
    Element root = document.addElement("Timetable");
    if (gen) {
        Element generator = root.addElement("Generator");
        generator.addAttribute("version", "2.0");
        generator.addElement("DaysPerWeek").setText(String.valueOf(iNrDays));
        generator.addElement("SlotsPerDay").setText(String.valueOf(iNrHours));
        generator.addElement("NrRooms").setText(cfg.getProperty("Generator.NrRooms", "20"));
        generator.addElement("NrInstructors").setText(cfg.getProperty("Generator.NrInstructors", "20"));
        generator.addElement("NrClasses").setText(cfg.getProperty("Generator.NrClasses", "20"));
        generator.addElement("FillFactor").setText(cfg.getProperty("Generator.FillFactor", "0.8"));
        generator.addElement("ActivityLengthMax").setText(cfg.getProperty("Generator.ActivityLengthMax", "5"));
        generator.addElement("NrGroupsOfRooms").setText(cfg.getProperty("Generator.NrGroupsOfRooms", "20"));
        generator.addElement("NrRoomsInGroupMin").setText(cfg.getProperty("Generator.NrRoomsInGroupMin", "1"));
        generator.addElement("NrRoomsInGroupMax").setText(cfg.getProperty("Generator.NrRoomsInGroupMax", "10"));
        generator.addElement("NrRoomInGroupMin").setText(cfg.getProperty("Generator.NrRoomInGroupMin", "1"));
        generator.addElement("HardFreeResource").setText(cfg.getProperty("Generator.HardFreeResource", "0.05"));
        generator.addElement("SoftFreeResource").setText(cfg.getProperty("Generator.SoftFreeResource", "0.3"));
        generator.addElement("SoftUsedResource").setText(cfg.getProperty("Generator.SoftUsedResource", "0.05"));
        generator.addElement("SoftUsedActivity").setText(cfg.getProperty("Generator.SoftUsedActivity", "0.05"));
        generator.addElement("SoftFreeActivity").setText(cfg.getProperty("Generator.SoftFreeActivity", "0.3"));
        generator.addElement("HardFreeActivity").setText(cfg.getProperty("Generator.HardFreeActivity", "0.05"));
        generator.addElement("NrDependencies").setText(cfg.getProperty("Generator.NrDependencies", "50"));
    }
    ArrayList<Resource> rooms = new ArrayList<Resource>();
    ArrayList<Resource> classes = new ArrayList<Resource>();
    ArrayList<Resource> instructors = new ArrayList<Resource>();
    ArrayList<Resource> specials = new ArrayList<Resource>();
    ArrayList<Dependence> dependencies = new ArrayList<Dependence>();
    for (Constraint<Activity, Location> c : constraints()) {
        if (c instanceof Resource) {
            Resource r = (Resource) c;
            switch(r.getType()) {
                case Resource.TYPE_ROOM:
                    rooms.add(r);
                    break;
                case Resource.TYPE_CLASS:
                    classes.add(r);
                    break;
                case Resource.TYPE_INSTRUCTOR:
                    instructors.add(r);
                    break;
                default:
                    specials.add(r);
            }
        } else if (c instanceof Dependence) {
            dependencies.add((Dependence) c);
        }
    }
    Element problem = root.addElement("Problem");
    problem.addAttribute("version", "2.0");
    Element problemGen = problem.addElement("General");
    problemGen.addElement("DaysPerWeek").setText(String.valueOf(iNrDays));
    problemGen.addElement("SlotsPerDay").setText(String.valueOf(iNrHours));
    Element resourceGen = problemGen.addElement("Resources");
    resourceGen.addElement("Classrooms").setText(String.valueOf(rooms.size()));
    resourceGen.addElement("Teachers").setText(String.valueOf(instructors.size()));
    resourceGen.addElement("Classes").setText(String.valueOf(classes.size()));
    resourceGen.addElement("Special").setText(String.valueOf(specials.size()));
    problemGen.addElement("Activities").setText(String.valueOf(variables().size()));
    problemGen.addElement("Dependences").setText(String.valueOf(dependencies.size()));
    Element resources = problem.addElement("Resources");
    Element resEl = resources.addElement("Classrooms");
    for (Resource r : rooms) {
        Element el = resEl.addElement("Resource");
        el.addAttribute("id", r.getResourceId());
        el.addElement("Name").setText(r.getName());
        Element pref = el.addElement("TimePreferences");
        for (Integer slot : new TreeSet<Integer>(r.getDiscouragedSlots())) pref.addElement("Soft").setText(slot.toString());
        for (Integer slot : new TreeSet<Integer>(r.getProhibitedSlots())) pref.addElement("Hard").setText(slot.toString());
    }
    resEl = resources.addElement("Teachers");
    for (Resource r : instructors) {
        Element el = resEl.addElement("Resource");
        el.addAttribute("id", r.getResourceId());
        el.addElement("Name").setText(r.getName());
        Element pref = el.addElement("TimePreferences");
        for (Integer slot : new TreeSet<Integer>(r.getDiscouragedSlots())) pref.addElement("Soft").setText(slot.toString());
        for (Integer slot : new TreeSet<Integer>(r.getProhibitedSlots())) pref.addElement("Hard").setText(slot.toString());
    }
    resEl = resources.addElement("Classes");
    for (Resource r : classes) {
        Element el = resEl.addElement("Resource");
        el.addAttribute("id", r.getResourceId());
        el.addElement("Name").setText(r.getName());
        Element pref = el.addElement("TimePreferences");
        for (Integer slot : new TreeSet<Integer>(r.getDiscouragedSlots())) pref.addElement("Soft").setText(slot.toString());
        for (Integer slot : new TreeSet<Integer>(r.getProhibitedSlots())) pref.addElement("Hard").setText(slot.toString());
    }
    resEl = resources.addElement("Special");
    for (Resource r : specials) {
        Element el = resEl.addElement("Resource");
        el.addAttribute("id", r.getResourceId());
        el.addElement("Name").setText(r.getName());
        Element pref = el.addElement("TimePreferences");
        for (Integer slot : new TreeSet<Integer>(r.getDiscouragedSlots())) pref.addElement("Soft").setText(slot.toString());
        for (Integer slot : new TreeSet<Integer>(r.getProhibitedSlots())) pref.addElement("Hard").setText(slot.toString());
    }
    boolean hasSolution = false;
    Element actEl = problem.addElement("Activities");
    for (Activity a : variables()) {
        Element el = actEl.addElement("Activity");
        el.addAttribute("id", a.getActivityId());
        el.addElement("Name").setText(a.getName());
        el.addElement("Length").setText(String.valueOf(a.getLength()));
        if (assignment.getValue(a) != null)
            hasSolution = true;
        Element pref = el.addElement("TimePreferences");
        for (Integer slot : new TreeSet<Integer>(a.getDiscouragedSlots())) pref.addElement("Soft").setText(slot.toString());
        for (Integer slot : new TreeSet<Integer>(a.getProhibitedSlots())) pref.addElement("Hard").setText(slot.toString());
        Element reqRes = el.addElement("RequiredResources");
        for (List<Resource> gr : a.getResourceGroups()) {
            if (gr.size() == 1) {
                reqRes.addElement("Resource").setText(gr.get(0).getResourceId());
            } else {
                Element grEl = reqRes.addElement("Group").addAttribute("conjunctive", "no");
                for (Resource r : gr) grEl.addElement("Resource").setText(r.getResourceId());
            }
        }
    }
    Element depEl = problem.addElement("Dependences");
    for (Dependence d : dependencies) {
        Element el = depEl.addElement("Dependence");
        el.addAttribute("id", d.getResourceId());
        el.addElement("FirstActivity").setText((d.first()).getActivityId());
        el.addElement("SecondActivity").setText((d.second()).getActivityId());
        switch(d.getType()) {
            case Dependence.TYPE_AFTER:
                el.addElement("Operator").setText("After");
                break;
            case Dependence.TYPE_BEFORE:
                el.addElement("Operator").setText("Before");
                break;
            case Dependence.TYPE_CLOSELY_BEFORE:
                el.addElement("Operator").setText("Closely before");
                break;
            case Dependence.TYPE_CLOSELY_AFTER:
                el.addElement("Operator").setText("Closely after");
                break;
            case Dependence.TYPE_CONCURRENCY:
                el.addElement("Operator").setText("Concurrently");
                break;
            default:
                el.addElement("Operator").setText("Unknown");
        }
    }
    if (hasSolution) {
        Element solutionEl = root.addElement("Solution");
        solutionEl.addAttribute("version", "2.0");
        for (Activity a : variables()) {
            Element el = solutionEl.addElement("Activity");
            el.addAttribute("id", a.getActivityId());
            Location location = assignment.getValue(a);
            if (location != null) {
                el.addElement("StartTime").setText(String.valueOf(location.getSlot()));
                Element res = el.addElement("UsedResources");
                for (int i = 0; i < location.getResources().length; i++) res.addElement("Resource").setText(location.getResources()[i].getResourceId());
            }
        }
    }
    FileOutputStream fos = new FileOutputStream(outFile);
    (new XMLWriter(fos, OutputFormat.createPrettyPrint())).write(document);
    fos.flush();
    fos.close();
}

Example 15 with Constraint

use of org.cpsolver.ifs.model.Constraint in project cpsolver by UniTime.

the class StructuredCSPModel method generate.

@SuppressWarnings("unchecked")
private void generate(long seed) {
    int nrVariables = iProperties.getPropertyInt("CSP.NrVariables", 60);
    int nrValues = iProperties.getPropertyInt("CSP.DomainSize", 15);
    int nrKernels = iProperties.getPropertyInt("CSP.NrKernels", 2);
    int nrKernelVariables = iProperties.getPropertyInt("CSP.KernelSize", 8);
    int nrPairValues = nrValues * nrValues;
    float tightnessPerc = iProperties.getPropertyFloat("CSP.Tightness", 0.01f);
    float kernelTightnessPerc = iProperties.getPropertyFloat("CSP.KernelTightness", 0.097f);
    int nrCompatiblePairs = (int) Math.round((1.0 - tightnessPerc) * nrPairValues);
    int kernelNrCompatiblePairs = (int) Math.round((1.0 - kernelTightnessPerc) * nrPairValues);
    int nrPairVariables = (nrVariables * (nrVariables - 1)) / 2;
    int nrPairKernelVariables = (nrKernelVariables * (nrKernelVariables - 1)) / 2;
    nrPairVariables -= nrKernels * nrPairKernelVariables;
    float densityPerc = iProperties.getPropertyFloat("CSP.Density", 0.01f);
    float densityKernelPerc = iProperties.getPropertyFloat("CSP.KernelDensity", 0.097f);
    int density = Math.round(densityPerc * nrPairVariables);
    int kernelDensity = Math.round(densityKernelPerc * nrPairKernelVariables);
    Random rnd = new Random(seed);
    List<CSPVariable> generalVariables = new ArrayList<CSPVariable>(nrVariables - (nrKernels * nrKernelVariables));
    int varId = 1;
    for (int i = 0; i < nrVariables - (nrKernels * nrKernelVariables); i++) {
        CSPVariable var = new CSPVariable(varId++, nrValues);
        generalVariables.add(var);
        addVariable(var);
    }
    sLogger.debug("Created " + generalVariables.size() + " general variables.");
    List<CSPVariable>[] kernelVariables = new ArrayList[nrKernels];
    for (int k = 0; k < nrKernels; k++) {
        kernelVariables[k] = new ArrayList<CSPVariable>(nrKernelVariables);
        for (int i = 0; i < nrKernelVariables; i++) {
            CSPVariable var = new CSPVariable(varId++, nrValues, k);
            kernelVariables[k].add(var);
            addVariable(var);
        }
        if (k == 0)
            sLogger.debug("Created " + kernelVariables[0].size() + " kernel variables (per kernel).");
    }
    sLogger.debug("Created " + variables().size() + " variables at total.");
    int constId = 1;
    List<CSPBinaryConstraint> generalConstraints = new ArrayList<CSPBinaryConstraint>(density);
    for (int i = 0; i < density; i++) {
        CSPBinaryConstraint c = new CSPBinaryConstraint(constId++, nrCompatiblePairs);
        generalConstraints.add(c);
        addConstraint(c);
    }
    sLogger.debug("Created " + generalConstraints.size() + " general constraints (tightness=" + tightnessPerc + ").");
    List<CSPBinaryConstraint>[] kernelConstraints = new List[nrKernels];
    for (int k = 0; k < nrKernels; k++) {
        kernelConstraints[k] = new ArrayList<CSPBinaryConstraint>(kernelDensity);
        for (int i = 0; i < kernelDensity; i++) {
            CSPBinaryConstraint c = new CSPBinaryConstraint(constId++, kernelNrCompatiblePairs);
            kernelConstraints[k].add(c);
            addConstraint(c);
        }
        if (k == 0)
            sLogger.debug("Created " + kernelConstraints[0].size() + " kernel constraints (per kernel, tightness=" + kernelTightnessPerc + ").");
    }
    sLogger.debug("Created " + constraints().size() + " constraints at total.");
    for (int k = 0; k < nrKernels; k++) {
        buildBinaryConstraintGraph(kernelVariables[k], kernelConstraints[k], rnd);
    }
    buildBinaryConstraintGraph2(variables(), nrPairVariables, generalConstraints, rnd);
    for (Constraint<CSPVariable, CSPValue> c : constraints()) {
        CSPBinaryConstraint constraint = (CSPBinaryConstraint) c;
        constraint.init(rnd);
    }
    if (iProperties.getPropertyBoolean("General.MPP", false)) {
        for (CSPVariable variable : variables()) {
            variable.generateInitialValue(rnd);
        }
    }
}