Happy Holidays !
Test case
doc1 : test -- one two three
doc2 : test, one two three
doc3 : one two three
Search query : "one two three" by QueryParser and StandardAnalyzer
Question: why all of three documents have the same score? I really want
the doc3 has higher score because it is an exact match and short. Can
anybody explain this? I will appreciate a lot
Here is my code and its output
public class Test {
public static void main(String[] args){
test();
}
private static void test(){
String[] contents = {"test -- one two three",
"test, one two three",
"one two three"};
Directory dir = new RAMDirectory();
try {
IndexWriter writer = new IndexWriter(dir, new
StandardAnalyzer(Version.LUCENE_30), IndexWriter.MaxFieldLength.UNLIMITED);
for (int i=0; i<contents.length; i++){
Document doc = new Document();
doc.add(new Field("de", contents[i], Field.Store.YES,
Field.Index.ANALYZED));
writer.addDocument(doc);
}
writer.close();
IndexSearcher searcher = new IndexSearcher(dir);
QueryParser parser = new QueryParser(Version.LUCENE_30,"de", new
StandardAnalyzer(Version.LUCENE_30));
Query q = parser.parse("one two three");
TopDocs topDocs = searcher.search(q, 10);
for (ScoreDoc scoreDoc : topDocs.scoreDocs){
Document doc = searcher.doc(scoreDoc.doc);
System.out.println(doc.get("de"));
Explanation explan = searcher.explain(q, scoreDoc.doc);
System.out.println(explan.toString());
}
} catch (CorruptIndexException e) {
e.printStackTrace();
} catch (LockObtainFailedException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
test -- one two three
0.6168854 = (MATCH) sum of:
0.20562847 = (MATCH) weight(de:one in 0), product of:
0.57735026 = queryWeight(de:one), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:one in 0), product of:
1.0 = tf(termFreq(de:one)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=0)
0.20562847 = (MATCH) weight(de:two in 0), product of:
0.57735026 = queryWeight(de:two), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:two in 0), product of:
1.0 = tf(termFreq(de:two)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=0)
0.20562847 = (MATCH) weight(de:three in 0), product of:
0.57735026 = queryWeight(de:three), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:three in 0), product of:
1.0 = tf(termFreq(de:three)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=0)
test, one two three
0.6168854 = (MATCH) sum of:
0.20562847 = (MATCH) weight(de:one in 1), product of:
0.57735026 = queryWeight(de:one), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:one in 1), product of:
1.0 = tf(termFreq(de:one)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=1)
0.20562847 = (MATCH) weight(de:two in 1), product of:
0.57735026 = queryWeight(de:two), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:two in 1), product of:
1.0 = tf(termFreq(de:two)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=1)
0.20562847 = (MATCH) weight(de:three in 1), product of:
0.57735026 = queryWeight(de:three), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:three in 1), product of:
1.0 = tf(termFreq(de:three)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=1)
one two three
0.6168854 = (MATCH) sum of:
0.20562847 = (MATCH) weight(de:one in 2), product of:
0.57735026 = queryWeight(de:one), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:one in 2), product of:
1.0 = tf(termFreq(de:one)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=2)
0.20562847 = (MATCH) weight(de:two in 2), product of:
0.57735026 = queryWeight(de:two), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:two in 2), product of:
1.0 = tf(termFreq(de:two)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=2)
0.20562847 = (MATCH) weight(de:three in 2), product of:
0.57735026 = queryWeight(de:three), product of:
0.71231794 = idf(docFreq=3, maxDocs=3)
0.8105233 = queryNorm
0.35615897 = (MATCH) fieldWeight(de:three in 2), product of:
1.0 = tf(termFreq(de:three)=1)
0.71231794 = idf(docFreq=3, maxDocs=3)
0.5 = fieldNorm(field=de, doc=2)
Best regards,
Qi Li
