dev.langchain4j.store.embedding

Class CosineSimilarity

java.lang.Object

dev.langchain4j.store.embedding.CosineSimilarity

public class CosineSimilarity
extends Object

Constructor Summary

Constructors

Constructor and Description
CosineSimilarity()

Method Summary

Modifier and Type	Method and Description
static double	between(Embedding embeddingA, Embedding embeddingB) Calculates cosine similarity between two vectors.
static double	fromRelevanceScore(double relevanceScore) Converts relevance score into cosine similarity.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CosineSimilarity

public CosineSimilarity()

Method Detail

between

public static double between(Embedding embeddingA,
                             Embedding embeddingB)

Calculates cosine similarity between two vectors.

Cosine similarity measures the cosine of the angle between two vectors, indicating their directional similarity. It produces a value in the range:

-1 indicates vectors are diametrically opposed (opposite directions).

0 indicates vectors are orthogonal (no directional similarity).

1 indicates vectors are pointing in the same direction (but not necessarily of the same magnitude).

Not to be confused with cosine distance ([0..2]), which quantifies how different two vectors are.

Parameters:

embeddingA - first embedding vector

embeddingB - second embedding vector

Returns:

cosine similarity in the range [-1..1]

fromRelevanceScore

public static double fromRelevanceScore(double relevanceScore)

Converts relevance score into cosine similarity.

Parameters:

relevanceScore - Relevance score in the range [0..1] where 0 is not relevant and 1 is relevant.

Returns:

Cosine similarity in the range [-1..1] where -1 is not relevant and 1 is relevant.