agrag.evidence.search.reciprocal_rank_fusion

reciprocal_rank_fusion(rankings:Sequence[Sequence[str]], *, constant:int = 60) -> dict[str, float]

Fuse ranked id lists into one score per id.

Each list adds 1 / (constant + rank) to the score of every id it contains, with ranks starting at 1. An id that several lists rank highly scores highest.

Parameters:

• rankings (Sequence[Sequence[str]]) – Lists of ids, best first. An id should appear once per list.
• constant (int) – The damping constant of the formula. The value 60 is the one from the original RRF paper, and it damps the effect of the top ranks.

Returns:

• dict[str, float] – The fused score of each id that appears in any list.