Examples of org.terrier.matching.PostingListManager

org.terrier.matching.PostingListManager
The PostingListManager is reponsible for opening the appropriate posting lists {@link IterablePosting} giventhe MatchingQueryTerms object. Moreover, it knows how each Posting should be scored.
Plugins are also supported by PostingListManager. Each plugin class should implement the PostingListManagerPlugin interface, and be named explicitly in the matching.postinglist.manager.plugins property.
Properties:
- ignore.low.idf.terms - should terms with low IDF (i.e. very frequent) be ignored? Defaults to true, i.e. ignored
- matching.postinglist.manager.plugins - Comma delimited list of PostingListManagerPlugin classes to load.
Example Usage
Following code shows how term-at-a-time matching may occur using the PostingListManager:
```
  MatchingQueryTerms mqt; Index index; PostingListManager plm = new PostingListManager(index, index.getCollectionStatistics(), mqt); plm.prepare(false); for(int term = 0;term < plm.size(); term++) { IterablePosting ip = plm.get(term); while(ip.next() != IterablePosting.EOL) { double score = plm.score(term); int id = ip.getId(); } } plm.close(); 
```
@author Nicola Tonellotto and Craig Macdonald @since 3.5 @see org.terrier.matching.Matching

      if (phraseQTWfnid < 1 || phraseQTWfnid > 4) {
        System.err
        .println("ERROR: Wrong function id specified for ProximityScoreModifierTREC2009");
      }
  
      PostingListManager plm = new PostingListManager(index, index.getCollectionStatistics(), terms);
      plm.prepare(false);
      phraseTerms = new String[plm.getNumTerms()];
      EntryStatistics[] es = new EntryStatistics[plm.getNumTerms()];
      IterablePosting[] ips = new IterablePosting[plm.getNumTerms()];
      
      for (int i = 0; i < plm.getNumTerms(); i++) {
        phraseTerms[i] = plm.getTerm(i);
        es[i] = plm.getStatistics(i);
        ips[i] = plm.getPosting(i);
      }
      
      final int phraseLength = phraseTerms.length;
      if (phraseLength == 1)
        return false;

View Full Code Here

  public ResultSet match(String queryNumber, MatchingQueryTerms queryTerms) throws IOException 
  {
    final long starttime = System.currentTimeMillis();
    initialise(queryTerms);
    
    plm = new PostingListManager(index, super.collectionStatistics, queryTerms);
    if (MATCH_EMPTY_QUERY && plm.size() == 0)
    {
      // Check whether we need to match an empty query. If so, then return the existing result set.
      resultSet = new CollectionResultSet(collectionStatistics.getNumberOfDocuments());
      resultSet.setExactResultSize(collectionStatistics.getNumberOfDocuments());

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  @Override
  public ResultSet match(String queryNumber, MatchingQueryTerms queryTerms) throws IOException 
  {
    // The first step is to initialise the arrays of scores and document ids.
    initialise(queryTerms);
    plm = new PostingListManager(index, super.collectionStatistics, queryTerms);
    plm.prepare(true);
    
    // Check whether we need to match an empty query. If so, then return the existing result set.
    String[] queryTermStrings = queryTerms.getTerms();
    if (MATCH_EMPTY_QUERY && queryTermStrings.length == 0) {

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Related Classes of org.terrier.matching.PostingListManager

org.terrier.matching.daat.Full

org.terrier.matching.dsms.DependenceScoreModifier

org.terrier.matching.taat.Full

org.terrier.structures.EntryStatistics

org.terrier.structures.LexiconEntry

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