I want to override TermScorer.score() method to take position info
into scoring. e.g. any occurence whose position is less than 100 will
get a boost
The original score method:
public float score() {
assert doc != -1;
int f = freqs[pointer];
float raw = // compute tf(f)*weight
f < SCORE_CACHE_SIZE // check cache
? scoreCache[f] // cache hit
: getSimilarity().tf(f)*weightValue; // cache miss
return norms == null ? raw : raw * SIM_NORM_DECODER[norms[doc] &
0xFF]; // normalize for field
}
I want to modify it to:
public float score() {
assert doc != -1;
int f = freqs[pointer];
float raw = // compute tf(f)*weight
f < SCORE_CACHE_SIZE // check cache
? scoreCache[f] // cache hit
: getSimilarity().tf(f)*weightValue; // cache miss
//modified
int[] termPositions=getPositionOfDoc(doc);
float positionBoost=1.0;
for(int pos:termPositions){
positionBoost*=getPositionScore(pos);
}
raw*=positionBoost;
//end
return norms == null ? raw : raw * SIM_NORM_DECODER[norms[doc] &
0xFF]; // normalize for field
}
So I need to get position info of a term given a doc id by int[]
getPositionOfDoc(doc);
I read some codes of SpanQuery
TermPositions positions;
while(positions.next()){//enum all docs containing the term
doc = positions.doc();
freq = positions.freq(); //current doc's tf
for(int i=0;i<freq;i++){
position = positions.nextPosition(); // get all the
position information of current doc
}
}
But to get the doc's position info, I have to sequentially call
positions.next() like this
int[] getPositionOfDoc(doc){
while(positions.next()){
currentDoc = positions.doc();
if(currentDoc==doc){// find it
freq = positions.freq(); //current doc's tf
for(int i=0;i<freq;i++){
//collect info
}
return result;
}
}
}
is there any method like random access to the position of doc? as far
as I know, lucene's invert index is implemented by skip list which
support log(n) search
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
