High performance distances and similarities for various dense and sparse representations with primary focus on applications in NLP and recommender systems.

Supported and Planned Object Types

• matrix from base R
• dgCMatrix, dgRMatrix and dgTMatrix from Matrix package
• simple_triplet_matrix from slam package
• data.frames in primary-secondary-value (psv) format
• list of named numeric or character vectors

Distances for 2D Representations

	matrix	dgCMatrix	dgRMatrix	dgTMatrix	slam	psv	list
cosine	✔	✔	✔	✔		✔
euclidean	✔	✔	✔	✔		✔
mahalanobis
jaccard

Aggregation Distances for 3D Representations

	dgCMatrix	dgRMatrix	dgTMatrix	slam	psv	list
centroid	✔	✔	✔		✔
semantic_min_max1	✔	✔	✔		✔
semantic_min_sum2	✔	✔	✔		✔

[1] More commonly known as "Relaxed Word Mover Distance" (RWMD) proposed in Kusner et. al. ‘From Word Embeddings To Document Distances’ (2015).

[2] Similar to RWMD measure, proposed in Mihalcea et.al. 'Corpus-Based and Knowledge-Based Measures of Text Semantic Similarity' (2006)

Transformations

norm_l1, norm_l2.