How the argument "goodRating" work in function "calcPredictionAccuracy" about recommenderlab HOT 3 CLOSED

I think the documentation was a little sparse on this one. I have added the following to ?calcPredictionAccuracy

If the ratings are a "topNList" and the observed data is a "realRatingMatrix" then \code{goodRating} is used to determine what rating in \code{data} is considered a good rating for calculating binary classification measures. This means that an item in the topNList is considered a true positive if it has a rating of \code{goodRating} or better in the observed data.

I hope this helps.

from recommenderlab.

I think I've figured it out.

The goodRating is for deciding whether the observed data should be classified to positive or negative, and for topNList method it gives the top n items as recommendation only conditional on the order of the value of predicting rating regardless of the value itself or any threshold.

It helps a lot. Thanks for helping!

from recommenderlab.

You are welcome.

from recommenderlab.