SpanWeightpublic class SpanWeight extends Object implements Weight| Copyright 2004 The Apache Software Foundation
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License. |
| Fields Summary |
|---|
| private Searcher | searcher | | private float | value | | private float | idf | | private float | queryNorm | | private float | queryWeight | | private Collection | terms | | private SpanQuery | query |
| Constructors Summary |
|---|
public SpanWeight(SpanQuery query, Searcher searcher)
this.searcher = searcher;
this.query = query;
this.terms = query.getTerms();
|
| Methods Summary |
|---|
| public org.apache.lucene.search.Explanation | explain(org.apache.lucene.index.IndexReader reader, int doc)
Explanation result = new Explanation();
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(searcher.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
Explanation fieldExpl = new Explanation();
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.setValue(tfExpl.getValue() *
idfExpl.getValue() *
fieldNormExpl.getValue());
result.addDetail(fieldExpl);
// 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,
query.getSimilarity(searcher),
reader.norms(query.getField()));
| | public float | sumOfSquaredWeights()
idf = this.query.getSimilarity(searcher).idf(terms, searcher);
queryWeight = idf * query.getBoost(); // compute query weight
return queryWeight * queryWeight; // square it
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