recommenderlab (version 0.1-2)

dissimilarity: Dissimilarity Calculation Between Rating Data

Description

Calculate dissimilarities between ratings by users and for items.

Usage

## S3 method for class 'binaryRatingMatrix':
dissimilarity(x, y = NULL, method = NULL, args = NULL, which="users")
## S3 method for class 'realRatingMatrix':
dissimilarity(x, y = NULL, method = NULL, args = NULL, which="users")

Arguments

x

a rating matrix.

y

NULL or a second rating matrix to calculate cross-dissimilarities.

method

dissimilarity measure to use. Available measures are typically "cosine", "pearson", "jaccard", etc. See dissimilarity for class itemMatrix in arules for details about measur

args

a list of additional arguments for the methods.

which

a character string indicating if the dissimilarity should be calculated between "users" or "items".

Value

• returns an object of class dist of an appropriate object (e.g., a matrix) to represent a cross-dissimilarity.

See Also

ratingMatrix, dissimilarity in arules.

Examples

data(MSWeb)

## between 5 users
dissimilarity(sample(MSWeb, 5), method = "jaccard")

## between first 3 items
dissimilarity(MSWeb[,1:3], method = "jaccard", which = "items")

## cross-dissimilarity between first 2 users and users 10-20
dissimilarity(MSWeb[1:2,], MSWeb[10:20,])