ttsolver.constraint
Class InstructorConstraint

java.lang.Object
  ifs.model.Constraint
      ttsolver.constraint.ResourceConstraint
          ttsolver.constraint.InstructorConstraint

public class InstructorConstraint
extends ResourceConstraint

Instructor constraint.
Classes with this instructor can not overlap in time. Also, for back-to-back classes, there is the following reasoning:

• if the distance is equal or below sNoPreferenceLimit .. no preference
• if the distance is above sNoPreferenceLimit and below sDiscouragedLimit .. constraint is discouraged (soft, preference = 1)
• if the distance is above sDiscouragedLimit and below sProhibitedLimit .. constraint is strongly discouraged (soft, preference = 2)
• if the distance is above sProhibitedLimit .. constraint is prohibited (hard)

Version:

1.0

Author:

Tomáš Müller

Field Summary

static double	sDiscouragedLimit Back-to-back classes: maximal distance for discouraged prefernce
static double	sNoPreferenceLimit Back-to-back classes: maximal distance for no prefernce
static double	sProhibitedLimit Back-to-back classes: maximal distance for strongly discouraged prefernce (everything above is prohibited)

Fields inherited from class ttsolver.constraint.ResourceConstraint

iDays, iResource, iSlotsPerDay

Constructor Summary

InstructorConstraint(String id, String name, int slotsPerDay, int days)
Constructor

Method Summary

void	computeConflicts(Value value, Set conflicts) The only method which has to be implemented by any constraint.
static int	getDistancePreference(Placement p1, Placement p2) Back-to-back preference of two placements (3 means prohibited)
int	getPreference() Overall back-to-back preference of this instructor
int	getPreference(Value value) Back-to-back preference of the given placement
int	getWorstPreference() Worst back-to-back preference of this instructor
boolean	inConflict(Value value) Returns true if the given assignment is inconsistent with the existing assignments respecting this constraint.
boolean	isConsistent(Value value1, Value value2) Returns true if the given assignments are consistent respecting this constraint.

Methods inherited from class ttsolver.constraint.ResourceConstraint

assigned, countUselessSlots, getDays, getName, getResource, getResourceId, getSlotsPerDay, printUsage, toString, unassigned

Methods inherited from class ifs.model.Constraint

addConstraintListener, addVariable, assignedVariables, countAssignedVariables, countVariables, getDescription, getId, getInfo, getModel, hashCode, isHard, removeConstraintListener, removeVariable, setModel, variables

Methods inherited from class java.lang.Object

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

Field Detail

sNoPreferenceLimit

public static double sNoPreferenceLimit

Back-to-back classes: maximal distance for no prefernce

sDiscouragedLimit

public static double sDiscouragedLimit

Back-to-back classes: maximal distance for discouraged prefernce

sProhibitedLimit

public static double sProhibitedLimit

Back-to-back classes: maximal distance for strongly discouraged prefernce (everything above is prohibited)

Constructor Detail

InstructorConstraint

public InstructorConstraint(String id,
                            String name,
                            int slotsPerDay,
                            int days)

Constructor

Parameters:

id - instructor id

name - instructor name

slotsPerDay - number of slots per day

days - number of days

Method Detail

getDistancePreference

public static int getDistancePreference(Placement p1,
                                        Placement p2)

Back-to-back preference of two placements (3 means prohibited)

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.

Overrides:

computeConflicts in class ResourceConstraint

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 ResourceConstraint

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 ResourceConstraint

getPreference

public int getPreference(Value value)

Back-to-back preference of the given placement

getPreference

public int getPreference()

Overall back-to-back preference of this instructor

getWorstPreference

public int getWorstPreference()

Worst back-to-back preference of this instructor