| """Reciprocal Rank Fusion for combining multiple ranked-id lists.""" | |
| def reciprocal_rank_fusion(rankings, k=60): | |
| """rankings: list of ranked-id lists (best first). Returns a single fused ranking.""" | |
| scores = {} | |
| for ranking in rankings: | |
| for rank, doc_id in enumerate(ranking, start=1): | |
| scores[doc_id] = scores.get(doc_id, 0.0) + 1.0 / (k + rank) | |
| return sorted(scores, key=scores.get, reverse=True) | |