org.terrier.matching.dsms

Class BooleanScoreModifier

java.lang.Object

org.terrier.matching.dsms.BooleanScoreModifier

All Implemented Interfaces:

Serializable, Cloneable, DocumentScoreModifier

public class BooleanScoreModifier
extends Object
implements DocumentScoreModifier, Serializable

If not all the query terms appear in a document, then this modifier zeros the document's score.

Author:

Vassilis Plachouras and Craig Macdonald

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.apache.log4j.Logger	logger the logger for this class
protected ArrayList<Query>	terms The terms to check.

Constructor Summary

Constructors

Constructor and Description
BooleanScoreModifier() An empty default constructor.
BooleanScoreModifier(ArrayList<Query> ts) A constructor where we specify which of the query terms should exist in the documents.

Method Summary

Methods

Modifier and Type	Method and Description
Object	clone() Clone this DSM.
String	getName() Returns the name of the document score modifier.
boolean	modifyScores(Index index, MatchingQueryTerms query, ResultSet resultSet) Zeros the scores of documents in which only some of the query terms appear.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected static final org.apache.log4j.Logger logger

the logger for this class

terms

protected ArrayList<Query> terms

The terms to check. If this is null, then we check for the whole query. This property can only be set from the constructor.

Constructor Detail

BooleanScoreModifier

public BooleanScoreModifier()

An empty default constructor.

BooleanScoreModifier

public BooleanScoreModifier(ArrayList<Query> ts)

A constructor where we specify which of the query terms should exist in the documents.

Parameters:

ts - ArrayList the query terms that should appear in the retrieved documents after applying this modifier.

Method Detail

getName

public String getName()

Returns the name of the document score modifier.

Specified by:

getName in interface DocumentScoreModifier

Returns:

String the name of the modifier.

modifyScores

public boolean modifyScores(Index index,
                   MatchingQueryTerms query,
                   ResultSet resultSet)

Zeros the scores of documents in which only some of the query terms appear.

Specified by:

modifyScores in interface DocumentScoreModifier

Parameters:

index - Index the data structures used for retrieval.

query - TermTreeNode[] the array of the query terms.

resultSet - ResultSet the set of retrieved documents.

Returns:

true if any scores have been altered

clone

public Object clone()

Clone this DSM. Note that terms is shall copied.

Specified by:

clone in interface DocumentScoreModifier

Overrides:

clone in class Object