bm25

Documentation

Overview

Package bm25 implements the Okapi BM25 ranking function for text retrieval.

Index

• type Scorer
  • func NewScorer() *Scorer
  • func NewScorerWithParams(k1, b float64) *Scorer
  • func (s *Scorer) AddDocument(id int64, text string)
  • func (s *Scorer) AddDocuments(ids []int64, texts []string)
  • func (s *Scorer) DocCount() int
  • func (s *Scorer) HasDocument(id int64) bool
  • func (s *Scorer) Score(query string) map[int64]float32
  • func (s *Scorer) ScoreDocIDs(query string, ids []int64) []float32
  • func (s *Scorer) TopK(query string, k int) ([]int64, []float32)

Types

type Scorer

type Scorer struct {
	// contains filtered or unexported fields
}

Scorer implements the BM25 scoring algorithm.

func NewScorer

func NewScorer() *Scorer

NewScorer creates a new BM25 scorer with default parameters.

func NewScorerWithParams

func NewScorerWithParams(k1, b float64) *Scorer

NewScorerWithParams creates a BM25 scorer with custom parameters.

func (*Scorer) AddDocument

func (s *Scorer) AddDocument(id int64, text string)

AddDocument adds a document to the BM25 index.

func (*Scorer) AddDocuments

func (s *Scorer) AddDocuments(ids []int64, texts []string)

AddDocuments adds multiple documents at once.

func (*Scorer) DocCount

func (s *Scorer) DocCount() int

DocCount returns the number of documents in the index.

func (*Scorer) HasDocument

func (s *Scorer) HasDocument(id int64) bool

HasDocument returns true if the document is already indexed.

func (*Scorer) Score

func (s *Scorer) Score(query string) map[int64]float32

Score computes BM25 scores for the query against all indexed documents. Returns a map from document ID to score.

func (*Scorer) ScoreDocIDs

func (s *Scorer) ScoreDocIDs(query string, ids []int64) []float32

ScoreDocIDs computes BM25 scores for the query against specific document IDs.

func (*Scorer) TopK

func (s *Scorer) TopK(query string, k int) ([]int64, []float32)

TopK returns the top K document IDs sorted by BM25 score.