org.terrier.matching.daat
Class FullNoPLM

java.lang.Object
  extended by org.terrier.matching.BaseMatching
      extended by 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
FullNoPLM(Index index)
          Create a new Matching instance based on the specified index
 
Method Summary
 java.lang.String getInfo()
          Return a human readable description of this Matching class
 ResultSet match(java.lang.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(java.lang.String queryNumber,
                       MatchingQueryTerms queryTerms)
                throws java.io.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:
java.io.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 java.lang.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


Terrier 3.5. Copyright © 2004-2011 University of Glasgow