The ALS algorithm takes the RDD of ratings for training. To do so, the following code illustrates for building the recommendation model using APIs:
val ratingsRDD = trainingData.rdd.map(row => { val userId = row.getString(0) val movieId = row.getString(1) val ratings = row.getString(2) Rating(userId.toInt, movieId.toInt, ratings.toDouble)})
The ratingsRDD is an RDD of ratings that contains userId, movieId, and the corresponding ratings from the training dataset we prepared in the previous step. On the other hand, a test RDD is also required for evaluating the model. The following testRDD also contains the same information coming from the test DataFrame we prepared ...
