R/predict.R

In audachang/recommenderlab.test: Lab for Developing and Testing Recommender Algorithms

setMethod("predict", signature(object = "Recommender"),
  function(object, newdata, n = 10, data=NULL, type="topNList", ...) {

    if(!is(newdata, "ratingMatrix") && !is(newdata, "numeric"))
      stop("newdata needs to be a subclass of class ratingMatrix or a numeric vector with user IDs!")

    object@predict(object@model, newdata, n = n, data=data, type= type, ...)
  }
)

### helper to return ratings
returnRatings <- function(ratings, newdata,
  type=c("topNList", "ratings", "ratingMatrix"), n,
  randomize = NULL, minRating = NA) {

  type <- match.arg(type)

  ratings <- as(ratings, "realRatingMatrix")
  ratings <- denormalize(ratings)

  if(type=="ratingMatrix") {
    ### replace with known ratings
    nm <- as(newdata, "matrix")
    rm <- as(ratings, "matrix")
    rm[!is.na(nm)] <- nm[!is.na(nm)]
    return(as(rm, "realRatingMatrix"))
  }


  ratings <- removeKnownRatings(ratings, newdata)
  if(type=="ratings") return(ratings)

  getTopNLists(ratings, n, randomize = randomize,minRating = minRating)
}