Package org.apache.mahout.cf.taste.impl.similarity

Class Summary

Class	Description
AbstractItemSimilarity
AveragingPreferenceInferrer	Implementations of this interface compute an inferred preference for a user and an item that the user has not expressed any preference for.
CachingItemSimilarity	Caches the results from an underlying ItemSimilarity implementation.
CachingUserSimilarity	Caches the results from an underlying UserSimilarity implementation.
CityBlockSimilarity	Implementation of City Block distance (also known as Manhattan distance) - the absolute value of the difference of each direction is summed.
EuclideanDistanceSimilarity	An implementation of a "similarity" based on the Euclidean "distance" between two users X and Y.
GenericItemSimilarity	A "generic" ItemSimilarity which takes a static list of precomputed item similarities and bases its responses on that alone.
GenericItemSimilarity.ItemItemSimilarity	Encapsulates a similarity between two items.
GenericUserSimilarity
GenericUserSimilarity.UserUserSimilarity
LogLikelihoodSimilarity	See http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.14.5962 and http://tdunning.blogspot.com/2008/03/surprise-and-coincidence.html.
PearsonCorrelationSimilarity	An implementation of the Pearson correlation.
SpearmanCorrelationSimilarity	Like PearsonCorrelationSimilarity, but compares relative ranking of preference values instead of preference values themselves.
TanimotoCoefficientSimilarity	An implementation of a "similarity" based on the Tanimoto coefficient, or extended Jaccard coefficient.
UncenteredCosineSimilarity	An implementation of the cosine similarity.