Package net.sf.tweety.logics.pl.util

Class CnfSampler

java.lang.Object

net.sf.tweety.commons.BeliefSetSampler<PlFormula,PlBeliefSet>

net.sf.tweety.logics.pl.util.CnfSampler

All Implemented Interfaces:

java.util.Iterator<PlBeliefSet>, BeliefSetIterator<PlFormula,PlBeliefSet>

public class CnfSampler
extends BeliefSetSampler<PlFormula,PlBeliefSet>

A simple sampler for propositional belief bases. This sampler always generates belief bases in CNF, i.e. every formula appearing in the belief base is a disjunction of literals.

Author:

Matthias Thimm

Field Summary

Fields

Modifier and Type	Field	Description
private double	maxVariableRatio	The maximum ratio of variables appearing in a single formula.

Fields inherited from class net.sf.tweety.commons.BeliefSetSampler

DEFAULT_MAXIMUM_BELIEFBASE_LENGTH, DEFAULT_MINIMUM_BELIEFBASE_LENGTH

Constructor Summary

Constructors

Constructor	Description
CnfSampler(Signature signature, double maxVariableRatio)	Creates a new sampler for the given signature.
CnfSampler(Signature signature, double maxVariableRatio, int minLength, int maxLength)	Creates a new sampler for the given signature.

Method Summary

Modifier and Type	Method	Description
PlBeliefSet	next()
PlFormula	sampleFormula()	Returns a random formula

Methods inherited from class net.sf.tweety.commons.BeliefSetSampler

getMaxLength, getMinLength, getSamplerSignature, hasNext

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Field Detail

maxVariableRatio

private double maxVariableRatio

The maximum ratio of variables appearing in a single formula.

Constructor Detail

CnfSampler

public CnfSampler(Signature signature,
                  double maxVariableRatio)

Creates a new sampler for the given signature.

Parameters:

signature - a signature

maxVariableRatio - the maximum ratio (a value between 0 and 1) of variables of the signature appearing in some formula.

CnfSampler

public CnfSampler(Signature signature,
                  double maxVariableRatio,
                  int minLength,
                  int maxLength)

Creates a new sampler for the given signature.

Parameters:

signature - a signature

maxVariableRatio - the maximum ratio (a value between 0 and 1) of variables of the signature appearing in some formula.

minLength - the minimum length of knowledge bases

maxLength - the maximum length of knowledge bases

Method Detail

next

public PlBeliefSet next()

Specified by:

next in interface BeliefSetIterator<PlFormula,PlBeliefSet>

Specified by:

next in interface java.util.Iterator<PlBeliefSet>

Specified by:

next in class BeliefSetSampler<PlFormula,PlBeliefSet>

sampleFormula

public PlFormula sampleFormula()

Returns a random formula

Returns:

a random formula