Package org.tweetyproject.logics.translators.adfpossibilistic

Class PossibilityDistribution

java.lang.Object

org.tweetyproject.logics.translators.adfpossibilistic.PossibilityDistribution

public class PossibilityDistribution
extends Object

Models a possibility distribution (PD) as defined in Christoph Beierle / Gabriele Kern-Isberner: Methoden Wissensbasierter Systeme

Author:

Jonas Schumacher

Field Summary

Fields

Modifier and Type	Field	Description
static final double	LOWER_BOUND	lower bound
static final double	UPPER_BOUND	upper bound

Constructor Summary

Constructors

Constructor	Description
PossibilityDistribution(PlSignature signature)	Creates a new possibility distribution (PD) mapping each given interpretation to 1.0 (least specific value = maximal entropy).

Method Summary

Modifier and Type	Method	Description
boolean	atLeastAsSpecificAs(PossibilityDistribution other)	Check whether this PD is at least as specific as another PD "other"
boolean	equals(Object other)
Double	getNecessity(PlFormula formula)	Gets the necessity measure of the given formula.
Set<PossibleWorld>	getPlausibleWorlds()	Returns all interpretations that are mapped to 1
Double	getPossibility(PossibleWorld w)	Gets the possibility of the given possible world.
Double	getPossibility(PlFormula formula)	Gets the possibility measure of the given formula.
Set<PossibleWorld>	getPossibleWorlds()	Returns all interpretations that are mapped to a possibility unequal to zero.
PlSignature	getSignature()	Returns the signature of the first-order language this PD is defined on.
boolean	isNormalized()	Check whether this PD is normalized, i.e.
void	setPossibility(PossibleWorld w, Double value)	Sets the possibility for the given possible world.
String	toString()

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

LOWER_BOUND

public static final double LOWER_BOUND

lower bound

See Also:

• Constant Field Values

UPPER_BOUND

public static final double UPPER_BOUND

upper bound

See Also:

• Constant Field Values

Constructor Details

PossibilityDistribution

public PossibilityDistribution(PlSignature signature)

Creates a new possibility distribution (PD) mapping each given interpretation to 1.0 (least specific value = maximal entropy).

Parameters:

signature - the signature of the language this PD is defined on.

Method Details

getPossibility

public Double getPossibility(PossibleWorld w)
                      throws IllegalArgumentException

Gets the possibility of the given possible world.

Parameters:

w - an possible world.

Returns:

the possibility of the given possible world.

Throws:

IllegalArgumentException - if the given possible world has no possibility in this PD.

setPossibility

public void setPossibility(PossibleWorld w,
 Double value)

Sets the possibility for the given possible world.

Parameters:

w - an possible world.

value - the possibility for the possible world.

getPossibility

public Double getPossibility(PlFormula formula)
                      throws IllegalArgumentException

Gets the possibility measure of the given formula. Throws an IllegalArgumentException when the language of the formula does not correspond to the language of the interpretations this PD is defined on. Otherwise the possibility of a formula is defined as the maximal possibility of its satisfying interpretations.

Parameters:

formula - a formula.

Returns:

the possibility of the given formula.

Throws:

IllegalArgumentException - if the languages of the formula does not correspond to the language of the interpretations this PD is defined on.

getNecessity

public Double getNecessity(PlFormula formula)
                    throws IllegalArgumentException

Gets the necessity measure of the given formula.

Parameters:

formula - a formula.

Returns:

the necessity of the given formula.

Throws:

IllegalArgumentException - if the languages of the formula does not correspond to the language of the interpretations this PD is defined on.

isNormalized

public boolean isNormalized()

Check whether this PD is normalized, i.e. whether its max. possibility value equals one.

Returns:

"true" if this PD is normalized

getPossibleWorlds

public Set<PossibleWorld> getPossibleWorlds()

Returns all interpretations that are mapped to a possibility unequal to zero.

Returns:

all interpretations that are mapped to a possibility unequal to zero.

getPlausibleWorlds

public Set<PossibleWorld> getPlausibleWorlds()

Returns all interpretations that are mapped to 1

Returns:

all interpretations that are mapped to 1

getSignature

public PlSignature getSignature()

Returns the signature of the first-order language this PD is defined on.

Returns:

the signature of the first-order language this PD is defined on.

atLeastAsSpecificAs

public boolean atLeastAsSpecificAs(PossibilityDistribution other)

Check whether this PD is at least as specific as another PD "other"

Parameters:

other - : another PD to be compared with

Returns:

true, if this PD is at least as specific as the other PD

toString

public String toString()

Overrides:

toString in class Object

equals

public boolean equals(Object other)

Overrides:

equals in class Object