Package net.sf.tweety.preferences

Class PreferenceOrder<T>

java.lang.Object

net.sf.tweety.preferences.PreferenceOrder<T>

Type Parameters:

T - the generic type of objects/pairs in this preference order

All Implemented Interfaces:

Iterable<net.sf.tweety.commons.util.Triple<T,T,Relation>>, Collection<net.sf.tweety.commons.util.Triple<T,T,Relation>>, Set<net.sf.tweety.commons.util.Triple<T,T,Relation>>, BinaryRelation<T>

public class PreferenceOrder<T>
extends Object
implements BinaryRelation<T>

This class extends the BinaryRelation-class with a check for totality and transitivity

Author:

Bastian Wolf

Constructor Summary

Constructors

Constructor	Description
PreferenceOrder()	Creates an empty HashSet of preference order.
PreferenceOrder(Collection<? extends net.sf.tweety.commons.util.Triple<T,T,Relation>> relations)	generates a preference order with a given set of elements

Method Summary

Modifier and Type	Method	Description
boolean	add(net.sf.tweety.commons.util.Triple<T,T,Relation> t)	adds a given pair of generic elements to the set.
boolean	addAll(Collection<? extends net.sf.tweety.commons.util.Triple<T,T,Relation>> c)	adds all given elements to the preference order
boolean	addPair(T f, T s, Relation relation)	adds two given (single) elements as pair into the set
void	clear()	clears the current preference order element set
boolean	compareEqualityWith(PreferenceOrder<T> po)	compares this preference order to another given one whether each relation is contained in both
boolean	contains(Object o)	checks whether this preference order contains a given pair
boolean	containsAll(Collection<?> c)	checks, whether all of the given elements are contained in the preference order
boolean	containsRelation(T a, T b)	checks whether this preference order contains a pair of given elements
boolean	containsTriple(T firstElement, T secondElement, Relation relation)	checks whether the given triple is contained
boolean	equals(Object obj)
net.sf.tweety.commons.util.Triple<T,T,Relation>	get(net.sf.tweety.commons.util.Triple<T,T,Relation> e)	checks existence and returns a demanded pair
Set<T>	getDomainElements()	(re-)computes a set of single elements in this preference order
LevelingFunction<T>	getLevelingFunction()	returns the ranking function for this preference order
net.sf.tweety.commons.util.Triple<T,T,Relation>	getTriple(T a, T b)	returns a pair if it consists of of two given elements
boolean	isEmpty()	returns whether the set is empty or not
boolean	isRelated(T a, T b)	returns whether the elements a and b are related
boolean	isTotal()	checks whether the set is total or not
boolean	isTransitive()	checks whether the given set is transitive or not
boolean	isValid()	checks whether the given set represents a valid preference order
Iterator<net.sf.tweety.commons.util.Triple<T,T,Relation>>	iterator()
Iterator<net.sf.tweety.commons.util.Triple<T,T,Relation>>	iterator(Set<net.sf.tweety.commons.util.Triple<T,T,Relation>> s)	returns an iterator over a set of triples
boolean	remove(Object o)	removes specific pair of the set
boolean	removeAll(Collection<?> c)	removes all given elements from the preference order
boolean	retainAll(Collection<?> c)
int	size()	returns the size of the set
void	strengthenElementInLF(T element)	strengthens the given element in this preference order in its leveling function
void	strengthenElementInRF(T element)	strengthens the given element in this preference order in its ranking function
Object[]	toArray()	returns an array containing all objects
<T> T[]	toArray(T[] a)	returns all elements in an array
String	toString()	returns a String with the elements of this set
void	weakenElementInLF(T element)	weakens the given element in this preference order in its leveling function
void	weakenElementInRF(T element)	weakens the given element in this preference order in its ranking function

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.Set

hashCode, spliterator

Constructor Detail

PreferenceOrder

public PreferenceOrder()

Creates an empty HashSet of preference order.

PreferenceOrder

public PreferenceOrder(Collection<? extends net.sf.tweety.commons.util.Triple<T,T,Relation>> relations)

generates a preference order with a given set of elements

Parameters:

relations - the set of given element pairs

Method Detail

getLevelingFunction

public LevelingFunction<T> getLevelingFunction()

returns the ranking function for this preference order

Returns:

the ranking function for this preference order

add

public boolean add(net.sf.tweety.commons.util.Triple<T,T,Relation> t)

adds a given pair of generic elements to the set.

Specified by:

add in interface BinaryRelation<T>

Specified by:

add in interface Collection<T>

Specified by:

add in interface Set<T>

Parameters:

t - the given set

Returns:

true if successful, false if not

addPair

public boolean addPair(T f,
                       T s,
                       Relation relation)

adds two given (single) elements as pair into the set

Parameters:

f - first element of the new pair

s - second element of the new pair

relation - the relation

Returns:

true if successful, false if not

getDomainElements

public Set<T> getDomainElements()

(re-)computes a set of single elements in this preference order

Specified by:

getDomainElements in interface BinaryRelation<T>

Returns:

a set of the single elements in this binary relation

remove

public boolean remove(Object o)

removes specific pair of the set

Specified by:

remove in interface Collection<T>

Specified by:

remove in interface Set<T>

Parameters:

o - the pair to be removed

Returns:

true if successful, false if not

isEmpty

public boolean isEmpty()

returns whether the set is empty or not

Specified by:

isEmpty in interface Collection<T>

Specified by:

isEmpty in interface Set<T>

Returns:

true if empty, false if not

isRelated

public boolean isRelated(T a,
                         T b)

returns whether the elements a and b are related

Specified by:

isRelated in interface BinaryRelation<T>

Parameters:

a - the first element to be checked

b - the second element to be checked

Returns:

true if related, false if not.

iterator

public Iterator<net.sf.tweety.commons.util.Triple<T,T,Relation>> iterator(Set<net.sf.tweety.commons.util.Triple<T,T,Relation>> s)

returns an iterator over a set of triples

Parameters:

s - a set of triples

Returns:

an iterator over a set of triples

get

public net.sf.tweety.commons.util.Triple<T,T,Relation> get(net.sf.tweety.commons.util.Triple<T,T,Relation> e)

checks existence and returns a demanded pair

Parameters:

e - the demanded pair

Returns:

a pair if it exists, null otherwise

getTriple

public net.sf.tweety.commons.util.Triple<T,T,Relation> getTriple(T a,
                                                                             T b)

returns a pair if it consists of of two given elements

Parameters:

a - the first element

b - the second element

Returns:

a pair if found, null if not

containsRelation

public boolean containsRelation(T a,
                                T b)

checks whether this preference order contains a pair of given elements

Parameters:

a - the first element

b - the second element

Returns:

true if pair is in this preference order, false if not

contains

public boolean contains(Object o)

checks whether this preference order contains a given pair

Specified by:

contains in interface Collection<T>

Specified by:

contains in interface Set<T>

Parameters:

o - the given pair

Returns:

true if pair is in this preference order, false if not

containsTriple

public boolean containsTriple(T firstElement,
                              T secondElement,
                              Relation relation)

checks whether the given triple is contained

Parameters:

firstElement - the first element

secondElement - the second element

relation - the relation

Returns:

true iff the given triple is contained

size

public int size()

returns the size of the set

Specified by:

size in interface Collection<T>

Specified by:

size in interface Set<T>

Returns:

the size of the set

toString

public String toString()

returns a String with the elements of this set

Specified by:

toString in interface BinaryRelation<T>

Overrides:

toString in class Object

Returns:

a String with the elements of this set

toArray

public Object[] toArray()

returns an array containing all objects

Specified by:

toArray in interface Collection<T>

Specified by:

toArray in interface Set<T>

Returns:

the Object[]-array

toArray

public <T> T[] toArray(T[] a)

returns all elements in an array

Specified by:

toArray in interface Collection<T>

Specified by:

toArray in interface Set<T>

Parameters:

a - is a given array

Returns:

an array

isTotal

public boolean isTotal()

checks whether the set is total or not

Specified by:

isTotal in interface BinaryRelation<T>

Returns:

true if total, false otherwise

isTransitive

public boolean isTransitive()

checks whether the given set is transitive or not

Specified by:

isTransitive in interface BinaryRelation<T>

Returns:

true if transitive, false otherwise

isValid

public boolean isValid()

checks whether the given set represents a valid preference order

Specified by:

isValid in interface BinaryRelation<T>

Returns:

true if valid, false if not

clear

public void clear()

clears the current preference order element set

Specified by:

clear in interface Collection<T>

Specified by:

clear in interface Set<T>

containsAll

public boolean containsAll(Collection<?> c)

checks, whether all of the given elements are contained in the preference order

Specified by:

containsAll in interface Collection<T>

Specified by:

containsAll in interface Set<T>

Returns:

true iff all elements are contained, false otherwise

removeAll

public boolean removeAll(Collection<?> c)

removes all given elements from the preference order

Specified by:

removeAll in interface Collection<T>

Specified by:

removeAll in interface Set<T>

Returns:

true if elements-set has changed, false if not

retainAll

public boolean retainAll(Collection<?> c)

Specified by:

retainAll in interface Collection<T>

Specified by:

retainAll in interface Set<T>

addAll

public boolean addAll(Collection<? extends net.sf.tweety.commons.util.Triple<T,T,Relation>> c)

adds all given elements to the preference order

Specified by:

addAll in interface Collection<T>

Specified by:

addAll in interface Set<T>

Returns:

true if element-set changed, false if not

iterator

public Iterator<net.sf.tweety.commons.util.Triple<T,T,Relation>> iterator()

Specified by:

iterator in interface Collection<T>

Specified by:

iterator in interface Iterable<T>

Specified by:

iterator in interface Set<T>

equals

public boolean equals(Object obj)

Specified by:

equals in interface Collection<T>

Specified by:

equals in interface Set<T>

Overrides:

equals in class Object

compareEqualityWith

public boolean compareEqualityWith(PreferenceOrder<T> po)

compares this preference order to another given one whether each relation is contained in both

Parameters:

po - the preference order to compare with

Returns:

true if both are equal, false if not

weakenElementInLF

public void weakenElementInLF(T element)

weakens the given element in this preference order in its leveling function

Parameters:

element - the element to be weaken

strengthenElementInLF

public void strengthenElementInLF(T element)

strengthens the given element in this preference order in its leveling function

Parameters:

element - the element to be strengthen

weakenElementInRF

public void weakenElementInRF(T element)

weakens the given element in this preference order in its ranking function

Parameters:

element - the element to be weaken

strengthenElementInRF

public void strengthenElementInRF(T element)

strengthens the given element in this preference order in its ranking function

Parameters:

element - the element to be strengthen