Once a model has been trained rrecsys may be used to generate either recommendation or predictions.
The prediction method will generate a new rating matrix with estimations on the missing ratings. Let’s predict using two models trained in the previous vignettes:
pSVD <- predict(svd) pIB <- predict(ibknn)
The predict method has a second argument, Round that rounds predicted values to the scale and binds them to the domain of the data set.
The recommend method generates a top-N list for each user:
rSVD <- recommendHPR(svd, topN = 3) rIB <- recommendHPR(ibknn, topN = 3) # Let’s compare results on user 3: rSVD rIB
The topN argument specifies the length of the recommended list for each user.