org.terrier.matching.daat

Class FullNoPLM

java.lang.Object

org.terrier.matching.BaseMatching

org.terrier.matching.daat.FullNoPLM

All Implemented Interfaces:

Matching

public class FullNoPLM
extends BaseMatching

Performs the matching of documents with a query, in a document-at-a-time (DAAT) manner. In particular, the posting lists for all query terms are processed in parallel (but without threads). In comparision to TAAT matching, this reduces the memory consumption during matching, as documents which will not make the final retrieved set are discarded. After matching, the document score modifiers are applied if necessary. Documents are matched in a document-at-a-time fashion.

Author:

Nicola Tonellotto and Craig Macdonald

See Also:

Matching, Full

Field Summary

Fields inherited from class org.terrier.matching.BaseMatching

collectionStatistics, documentModifiers, dsmNamespace, IGNORE_LOW_IDF_TERMS, index, invertedIndex, lexicon, logger, MATCH_EMPTY_QUERY, numberOfRetrievedDocuments, queryTermsToMatchList, resultSet, RETRIEVED_SET_SIZE, totalTime, wm

Constructor Summary

Constructors

Constructor and Description
FullNoPLM(Index index) Create a new Matching instance based on the specified index

Method Summary

Methods

Modifier and Type	Method and Description
String	getInfo() Return a human readable description of this Matching class
ResultSet	match(String queryNumber, MatchingQueryTerms queryTerms) Get a ResultSet for the given query terms.
protected double	scoreIt(WeightingModel[] wModels, Posting posting) calculate the score for this posting using the specified weighting models
protected int	selectMinimumDocId(it.unimi.dsi.fastutil.longs.LongPriorityQueue postingHeap) returns the docid of the lowest posting

Methods inherited from class org.terrier.matching.BaseMatching

finalise, getTotalTime, initialise, initialisePostings, setCollectionStatistics, updateEndTime, updateStartTime

Methods inherited from class java.lang.Object

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

Constructor Detail

FullNoPLM

public FullNoPLM(Index index)

Create a new Matching instance based on the specified index

Method Detail

match

public ResultSet match(String queryNumber,
              MatchingQueryTerms queryTerms)
                throws IOException

Get a ResultSet for the given query terms.

Specified by:

match in interface Matching

Specified by:

match in class BaseMatching

Parameters:

queryNumber - - some ID of the query

queryTerms - - query terms to match

Returns:

ResultSet - the matched results

Throws:

IOException - if a problem occurs during matching

scoreIt

protected double scoreIt(WeightingModel[] wModels,
             Posting posting)

calculate the score for this posting using the specified weighting models

Parameters:

wModels - weighting models for this term

posting - the posting for the current term

selectMinimumDocId

protected final int selectMinimumDocId(it.unimi.dsi.fastutil.longs.LongPriorityQueue postingHeap)

returns the docid of the lowest posting

getInfo

public String getInfo()

Description copied from class: BaseMatching

Return a human readable description of this Matching class

Specified by:

getInfo in interface Matching

Specified by:

getInfo in class BaseMatching