mlpy.knowledgerep.cbr.similarity.CosineSimilarity

class mlpy.knowledgerep.cbr.similarity.CosineSimilarity(**kwargs)[source]

Bases: mlpy.knowledgerep.cbr.similarity.ISimilarity

The cosine similarity model.

Cosine similarity is a measure of similarity between two vectors of an inner product space that measures the cosine of the angle between them. The cosine of 0 degree is 1, and it is less than 1 for any other angle. It is thus a judgement of orientation and not magnitude: tow vectors with the same orientation have a cosine similarity of 1, two vectors at 90 degrees have a similarity of 0, and two vectors diametrically opposed have a similarity of -1, independent of their magnitude [R1].

The cosine model employs the cosine_similarity function from the sklearn.metrics.pairwise module to determine similarity.

References

[R1](1, 2) Wikipidia::cosine_similarity

Methods

build_indexing_structure(data, id_map) Build the indexing structure.
compute_similarity(data_point) Computes the similarity.