public MediaLiteRatingPredictor(MyMediaLite.IRecommender recommender, IEnumerable <Relation> relations)
            : this(recommender)
        {
            if (recommender is SocialMF)
            {
                _relations = new SparseBooleanMatrix();

                foreach (var con in relations)
                {
                    _relations[_usersMap.ToInternalID(con.UserId), _usersMap.ToInternalID(con.ConnectedId)] = true;
                }

                ((SocialMF)recommender).UserRelation = _relations;
            }
        }
 public MediaLiteRatingPredictor(MyMediaLite.IRecommender recommender)
 {
     _ratingPredictor = recommender as MyMediaLite.RatingPrediction.IRatingPredictor;
     _usersMap        = new Mapping();
     _itemsMap        = new Mapping();
 }