SpanWeightpublic class SpanWeight extends Object implements Weight| Expert-only. Public for use by other weight implementations |
| Fields Summary |
|---|
| protected Similarity | similarity | | protected float | value | | protected float | idf | | protected float | queryNorm | | protected float | queryWeight | | protected Set | terms | | protected SpanQuery | query |
| Constructors Summary |
|---|
public SpanWeight(SpanQuery query, Searcher searcher)
this.similarity = query.getSimilarity(searcher);
this.query = query;
terms=new HashSet();
query.extractTerms(terms);
idf = this.query.getSimilarity(searcher).idf(terms, searcher);
|
| Methods Summary |
|---|
| public org.apache.lucene.search.Explanation | explain(org.apache.lucene.index.IndexReader reader, int doc)
ComplexExplanation result = new ComplexExplanation();
result.setDescription("weight("+getQuery()+" in "+doc+"), product of:");
String field = ((SpanQuery)getQuery()).getField();
StringBuffer docFreqs = new StringBuffer();
Iterator i = terms.iterator();
while (i.hasNext()) {
Term term = (Term)i.next();
docFreqs.append(term.text());
docFreqs.append("=");
docFreqs.append(reader.docFreq(term));
if (i.hasNext()) {
docFreqs.append(" ");
}
}
Explanation idfExpl =
new Explanation(idf, "idf(" + field + ": " + docFreqs + ")");
// explain query weight
Explanation queryExpl = new Explanation();
queryExpl.setDescription("queryWeight(" + getQuery() + "), product of:");
Explanation boostExpl = new Explanation(getQuery().getBoost(), "boost");
if (getQuery().getBoost() != 1.0f)
queryExpl.addDetail(boostExpl);
queryExpl.addDetail(idfExpl);
Explanation queryNormExpl = new Explanation(queryNorm,"queryNorm");
queryExpl.addDetail(queryNormExpl);
queryExpl.setValue(boostExpl.getValue() *
idfExpl.getValue() *
queryNormExpl.getValue());
result.addDetail(queryExpl);
// explain field weight
ComplexExplanation fieldExpl = new ComplexExplanation();
fieldExpl.setDescription("fieldWeight("+field+":"+query.toString(field)+
" in "+doc+"), product of:");
Explanation tfExpl = scorer(reader).explain(doc);
fieldExpl.addDetail(tfExpl);
fieldExpl.addDetail(idfExpl);
Explanation fieldNormExpl = new Explanation();
byte[] fieldNorms = reader.norms(field);
float fieldNorm =
fieldNorms!=null ? Similarity.decodeNorm(fieldNorms[doc]) : 0.0f;
fieldNormExpl.setValue(fieldNorm);
fieldNormExpl.setDescription("fieldNorm(field="+field+", doc="+doc+")");
fieldExpl.addDetail(fieldNormExpl);
fieldExpl.setMatch(Boolean.valueOf(tfExpl.isMatch()));
fieldExpl.setValue(tfExpl.getValue() *
idfExpl.getValue() *
fieldNormExpl.getValue());
result.addDetail(fieldExpl);
result.setMatch(fieldExpl.getMatch());
// combine them
result.setValue(queryExpl.getValue() * fieldExpl.getValue());
if (queryExpl.getValue() == 1.0f)
return fieldExpl;
return result;
| | public org.apache.lucene.search.Query | getQuery() return query;
| | public float | getValue() return value;
| | public void | normalize(float queryNorm)
this.queryNorm = queryNorm;
queryWeight *= queryNorm; // normalize query weight
value = queryWeight * idf; // idf for document
| | public org.apache.lucene.search.Scorer | scorer(org.apache.lucene.index.IndexReader reader)
return new SpanScorer(query.getSpans(reader), this,
similarity,
reader.norms(query.getField()));
| | public float | sumOfSquaredWeights()
queryWeight = idf * query.getBoost(); // compute query weight
return queryWeight * queryWeight; // square it
|
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