net.sf.cpsolver.coursett.constraint
Class SpreadConstraint

java.lang.Object
  net.sf.cpsolver.ifs.model.Constraint
      net.sf.cpsolver.coursett.constraint.SpreadConstraint

All Implemented Interfaces:

WeakeningConstraint

Direct Known Subclasses:

DepartmentSpreadConstraint

public class SpreadConstraint
extends Constraint
implements WeakeningConstraint

Spread given set of classes in time as much as possible. See DepartmentSpreadConstraint for more details.

Version:

CourseTT 1.1 (University Course Timetabling)
Copyright (C) 2006 Tomáš Müller
muller@unitime.org
Lazenska 391, 76314 Zlin, Czech Republic

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

Field Summary

static boolean

USE_MOST_IMPROVEMENT_ADEPTS

Fields inherited from class net.sf.cpsolver.ifs.model.Constraint

iAssignedVariables, iConstraintListeners, iId

Constructor Summary

SpreadConstraint(DataProperties config, String name)

SpreadConstraint(String name, double spreadFactor, int unassignmentsToWeaken, boolean interactiveMode)

Method Summary

void	addVariable(Variable variable) Add a variable to this constraint
void	assigned(long iteration, Value value) Given value is to be assigned to its varable.
void	computeConflicts(Value value, Set conflicts) The only method which has to be implemented by any constraint.
Placement	getAdept(Placement placement, int[][] nrCourses, Set conflicts)
Vector[][]	getCourses()
int[][]	getMaxCourses()
int	getMaxPenalty(Placement placement)
String	getName() Constraint's name -- for printing purposes
int[][]	getNrCourses()
int	getPenalty() Department balancing penalty for this department
int	getPenalty(Placement placement) Department balancing penalty of the given placement
int	getPenaltyEstimate()
boolean	inConflict(Value value) Returns true if the given assignment is inconsistent with the existing assignments respecting this constraint.
void	init() Initialize constraint (to be called after all variables are added to this constraint)
boolean	isConsistent(Value value1, Value value2) Returns true if the given assignments are consistent respecting this constraint.
String	toString()
void	unassigned(long iteration, Value value) Given value is unassigned from its varable.
void	weaken() Weaken the constraint.

Methods inherited from class net.sf.cpsolver.ifs.model.Constraint

addConstraintListener, assignedVariables, constraintListeners, countAssignedVariables, countVariables, equals, getDescription, getId, getModel, hashCode, isHard, removeConstraintListener, removeVariable, setModel, variables

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

USE_MOST_IMPROVEMENT_ADEPTS

public static boolean USE_MOST_IMPROVEMENT_ADEPTS

Constructor Detail

SpreadConstraint

public SpreadConstraint(String name,
                        double spreadFactor,
                        int unassignmentsToWeaken,
                        boolean interactiveMode)

SpreadConstraint

public SpreadConstraint(DataProperties config,
                        String name)

Method Detail

init

public void init()

Initialize constraint (to be called after all variables are added to this constraint)

getAdept

public Placement getAdept(Placement placement,
                          int[][] nrCourses,
                          Set conflicts)

computeConflicts

public void computeConflicts(Value value,
                             Set conflicts)

Description copied from class: Constraint

The only method which has to be implemented by any constraint. It returns the values which needs to be unassigned in order to make this constraint consistent with the given value if it is assigned to its variable. The computed list of conflicting values is added to the given set of conflicts.

Specified by:

computeConflicts in class Constraint

Parameters:

value - value to be assigned to its varaible

conflicts - resultant set of conflicting values

inConflict

public boolean inConflict(Value value)

Description copied from class: Constraint

Returns true if the given assignment is inconsistent with the existing assignments respecting this constraint. This method is used by MAC (see MacPropagation).

Overrides:

inConflict in class Constraint

isConsistent

public boolean isConsistent(Value value1,
                            Value value2)

Description copied from class: Constraint

Returns true if the given assignments are consistent respecting this constraint. This method is used by MAC (see MacPropagation).

Overrides:

isConsistent in class Constraint

weaken

public void weaken()

Description copied from interface: WeakeningConstraint

Weaken the constraint. This method is called if the constraint participates in an unassigned of a variable.

Specified by:

weaken in interface WeakeningConstraint

assigned

public void assigned(long iteration,
                     Value value)

Description copied from class: Constraint

Given value is to be assigned to its varable. In this method, the constraint should unassigns all varaibles which are in conflict with the given assignment because of this constraint.

Overrides:

assigned in class Constraint

unassigned

public void unassigned(long iteration,
                       Value value)

Description copied from class: Constraint

Given value is unassigned from its varable.

Overrides:

unassigned in class Constraint

getName

public String getName()

Description copied from class: Constraint

Constraint's name -- for printing purposes

Overrides:

getName in class Constraint

toString

public String toString()

Overrides:

toString in class Object

getPenalty

public int getPenalty()

Department balancing penalty for this department

getPenaltyEstimate

public int getPenaltyEstimate()

getMaxPenalty

public int getMaxPenalty(Placement placement)

getPenalty

public int getPenalty(Placement placement)

Department balancing penalty of the given placement

getMaxCourses

public int[][] getMaxCourses()

getNrCourses

public int[][] getNrCourses()

getCourses

public Vector[][] getCourses()

addVariable

public void addVariable(Variable variable)

Description copied from class: Constraint

Add a variable to this constraint

Overrides:

addVariable in class Constraint