recommenderlab (version 0.1-4)

realRatingMatrix-class: Class "realRatingMatrix": Real-valued Rating Matrix

Description

A matrix containing ratings (typically 1-5 stars, etc.).

Objects from the Class

Objects can be created by calls of the form new("realRatingMatrix", data = m), where m is sparse matrix of class dgCMatrix (see package Matrix), or by coercion from a regular matrix.

Extends

Class "ratingMatrix", directly.

See Also

See ratingMatrix inherited methods, binaryRatingMatrix, topNList, getList and getData.frame. Also see dgCMatrix, dgTMatrix and ngCMatrix in Matrix.

Examples

## create a matrix with ratings
m <- matrix(sample(c(NA,0:5),100, replace=TRUE, prob=c(.7,rep(.3/6,6))), 
	nrow=10, ncol=10, dimnames = list(
	    user=paste('u', 1:10, sep=''),
	    item=paste('u', 1:10, sep='')    
    ))
m

## coerce into a realRatingMAtrix
r <- as(m, "realRatingMatrix")
r

## get some information
dimnames(r)
rowCounts(r)
colCounts(r)
rowMeans(r)


## histogram of ratings
hist(getRatings(r), breaks="FD")

## inspect a subset
image(r[1:5,1:5])

## coerce it back to see if it worked
as(r, "matrix")

## coerce to data.frame
as(r, "data.frame")

## binarize into a binaryRatingMatrix with all 4+ rating a 1
b <- binarize(r, minRating=4)
b
as(b, "matrix")