net.sf.tweety.logics.commons.analysis

Class HsInconsistencyMeasure<B extends BeliefBase,S extends Formula>

java.lang.Object

net.sf.tweety.logics.commons.analysis.BeliefSetInconsistencyMeasure<S>

net.sf.tweety.logics.commons.analysis.HsInconsistencyMeasure<B,S>

Type Parameters:

B - some belief base type

S - some formula type

All Implemented Interfaces:

PostulateEvaluatable<S>, InconsistencyMeasure<BeliefSet<S>>

public class HsInconsistencyMeasure<B extends BeliefBase,S extends Formula>
extends BeliefSetInconsistencyMeasure<S>

This class implements the Hitting Set inconsistency measure as proposed in [Thimm, 2014, in preparation]. The inconsistency value is defined as one plus the minimal number of interpretations, s.t. every formula of the belief set is satisfied by at least one interpretation. This is equivalent in the cardinality of a minimal partitioning of the knowledge base such that each partition is consistent.

Author:

Matthias Thimm

Field Summary

Fields

Modifier and Type	Field and Description
private InterpretationIterator<S,B,? extends Interpretation<B,S>>	it Used for iterating over interpretations of the underlying language.

Fields inherited from interface net.sf.tweety.logics.commons.analysis.InconsistencyMeasure

MEASURE_TOLERANCE

Constructor Summary

Constructors

Constructor and Description
HsInconsistencyMeasure(InterpretationIterator<S,B,? extends Interpretation<B,S>> it) Creates a new inconsistency measure that uses the interpretations given by the given iterator.

Method Summary

Modifier and Type	Method and Description
private java.util.Collection<Interpretation<B,S>>	getHittingSet(java.util.Collection<S> formulas, int card, java.util.Collection<Interpretation<B,S>> interpretations) Determines a hitting set of the given cardinality.
java.lang.Double	inconsistencyMeasure(java.util.Collection<S> formulas) This method measures the inconsistency of the given set of formulas.
private boolean	isHittingSet(java.util.Collection<S> formulas, java.util.Collection<Interpretation<B,S>> candidate) Checks whether the given candidate is a hitting set.
java.lang.String	toString()

Methods inherited from class net.sf.tweety.logics.commons.analysis.BeliefSetInconsistencyMeasure

inconsistencyMeasure

Methods inherited from class java.lang.Object

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

Field Detail

it

private InterpretationIterator<S extends Formula,B extends BeliefBase,? extends Interpretation<B extends BeliefBase,S extends Formula>> it

Used for iterating over interpretations of the underlying language.

Constructor Detail

HsInconsistencyMeasure

public HsInconsistencyMeasure(InterpretationIterator<S,B,? extends Interpretation<B,S>> it)

Creates a new inconsistency measure that uses the interpretations given by the given iterator.

Parameters:

it - some interpretation iterator.

Method Detail

inconsistencyMeasure

public java.lang.Double inconsistencyMeasure(java.util.Collection<S> formulas)

Description copied from class: BeliefSetInconsistencyMeasure

This method measures the inconsistency of the given set of formulas.

Specified by:

inconsistencyMeasure in class BeliefSetInconsistencyMeasure<S extends Formula>

Parameters:

formulas - a collection of formulas.

Returns:

a Double indicating the degree of inconsistency.

getHittingSet

private java.util.Collection<Interpretation<B,S>> getHittingSet(java.util.Collection<S> formulas,
                                                                int card,
                                                                java.util.Collection<Interpretation<B,S>> interpretations)

Determines a hitting set of the given cardinality. If no such hitting set exists null is returned.

Parameters:

formulas - a collection of formulas

card - some cardinality.

interpretations - in addition to the card interpretations also use this set for satisfying formulas.

Returns:

a hitting set or null.

isHittingSet

private boolean isHittingSet(java.util.Collection<S> formulas,
                             java.util.Collection<Interpretation<B,S>> candidate)

Checks whether the given candidate is a hitting set.

Parameters:

formulas - some set of formulas

candidate - some set of interpretation.

Returns:

"true" if the candidate is a hitting set.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object