public Explanation explain(IndexReader reader, int doc) throws IOException {
ComplexExplanation result = new ComplexExplanation();
result.setDescription("weight(" + getQuery() + " in " + doc + "), product of:");
Explanation idfExpl = new Explanation(idf, "idf(docFreq=" + reader.docFreq(term) + ")");
// explain query weight
Explanation queryExpl = new Explanation();
queryExpl.setDescription("queryWeight(" + getQuery() + "), product of:");
Explanation boostExpl = new Explanation(getBoost(), "boost");
if (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
String field = term.field();
ComplexExplanation fieldExpl = new ComplexExplanation();
fieldExpl.setDescription("fieldWeight(" + term + " 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;
}
@Override
public final Explanation explain(BasicStats stats, float tfn) {
Explanation result = new Explanation();
result.setDescription(getClass().getSimpleName() + ", computed from: ");
result.setValue(score(stats, tfn));
result.addDetail(new Explanation(tfn, "tfn"));
return result;
}
/**
* Returns an explanation for the normalized term frequency.
*
* <p>The default normalization methods use the field length of the document and the average field
* length to compute the normalized term frequency. This method provides a generic explanation for
* such methods. Subclasses that use other statistics must override this method.
*/
public Explanation explain(BasicStats stats, float tf, float len) {
Explanation result = new Explanation();
result.setDescription(getClass().getSimpleName() + ", computed from: ");
result.setValue(tfn(stats, tf, len));
result.addDetail(new Explanation(tf, "tf"));
result.addDetail(new Explanation(stats.getAvgFieldLength(), "avgFieldLength"));
result.addDetail(new Explanation(len, "len"));
return result;
}
/**
* This method is no longer an official member of {@link Scorer}, but it is needed by SpanWeight
* to build an explanation.
*/
protected Explanation explain(final int doc) throws IOException {
Explanation tfExplanation = new Explanation();
int expDoc = advance(doc);
float phraseFreq = (expDoc == doc) ? freq : 0.0f;
tfExplanation.setValue(similarity.tf(phraseFreq));
tfExplanation.setDescription("tf(phraseFreq=" + phraseFreq + ")");
return tfExplanation;
}
/*
* (non-Javadoc)
*
* @see org.apache.lucene.search.Scorer#explain(int)
*/
public Explanation explain(int doc) throws IOException {
// TODO: Work out what a proper explanation would be here?
Explanation tfExplanation = new Explanation();
while (next() && doc() < doc) {}
float phraseFreq = (doc() == doc) ? freq : 0.0f;
tfExplanation.setValue(getSimilarity().tf(phraseFreq));
tfExplanation.setDescription("tf(phraseFreq=" + phraseFreq + ")");
return tfExplanation;
}
@Override
protected Explanation explain(int doc) throws IOException {
Explanation result = new Explanation();
// Add detail about tf/idf...
Explanation nonPayloadExpl = super.explain(doc);
result.addDetail(nonPayloadExpl);
// Add detail about payload
Explanation payloadExpl = function.explain(doc, payloadsSeen, payloadScore);
result.addDetail(payloadExpl);
result.setValue(nonPayloadExpl.getValue() * payloadExpl.getValue());
result.setDescription("PayloadNearQuery, product of:");
return result;
}
@Override
protected Explanation explain(final int doc) throws IOException {
ComplexExplanation result = new ComplexExplanation();
Explanation nonPayloadExpl = super.explain(doc);
result.addDetail(nonPayloadExpl);
// QUESTION: Is there a way to avoid this skipTo call? We need to know
// whether to load the payload or not
Explanation payloadBoost = new Explanation();
result.addDetail(payloadBoost);
float payloadScore = getPayloadScore();
payloadBoost.setValue(payloadScore);
// GSI: I suppose we could toString the payload, but I don't think that
// would be a good idea
payloadBoost.setDescription("scorePayload(...)");
result.setValue(nonPayloadExpl.getValue() * payloadScore);
result.setDescription("btq, product of:");
result.setMatch(
nonPayloadExpl.getValue() == 0 ? Boolean.FALSE : Boolean.TRUE); // LUCENE-1303
return result;
}
@Override
protected Explanation createExplain(Explanation innerExplain, IndexReader reader, int doc)
throws IOException {
if (reader instanceof BoboIndexReader) {
Explanation finalExpl = new Explanation();
finalExpl.addDetail(innerExplain);
_func.initializeReader((BoboIndexReader) reader, _jsonParam);
float innerValue = innerExplain.getValue();
float value = 0;
if (_func.useInnerScore()) value = _func.newScore(innerValue, doc);
else value = _func.newScore(doc);
finalExpl.setValue(value);
finalExpl.setDescription("Custom score: " + _func.getExplainString(innerValue, doc));
return finalExpl;
} else {
throw new IllegalStateException("reader not instance of " + BoboIndexReader.class);
}
}