The Jester5k
dataset is what we will be using to build our recommender system using collaborative filtering. It contains user ratings in the scale of -10 to 10 for several jokes. In this chapter, we will use these ratings as an input and produce ratings for jokes which the users have not seen or not rated before. For more information about the Jester5k
dataset, visit: http://www.ieor.berkeley.edu/%7Egoldberg/jester-data/
Fortunately, a sample of this data is available with the recommenderlab
package.
Let us quickly look at this data:
> library(recommenderlab, quietly = TRUE) > data("Jester5k") > str(Jester5k) Formal class 'realRatingMatrix' [package "recommenderlab"] with 2 slots ..@ data :Formal class 'dgCMatrix' [package "Matrix"] with 6 slots .. .. ..@ i : int [1:362106] 0 1 2 3 4 5 6 7 8 9 ... .. .. ..@ p : int [1:101] 0 3314 6962 10300 13442 18440 22513 27512 32512 35685 ... .. .. ..@ Dim : int [1:2] 5000 100 .. .. ..@ Dimnames...