public TSvdBoostedKnnModel TrainKnnModel(TSvdBoostedKnnModel model, List <IUser> trainUsers)
{
foreach (var user in trainUsers)
{
model.Users.Add(SvdBoostedKnnUser.FromIUser(user, NewUserFeatureGenerator.GetNewUserFeatures(model, user)));
}
return(model);
}
public IEnumerable <IRecommendation> GenerateRecommendations(IUser user, TSvdBoostedKnnModel model, List <IArtist> artists, int nearestNeighboursCount)
{
var svdBoostedKnnUser = SvdBoostedKnnUser.FromIUser(user, NewUserFeatureGenerator.GetNewUserFeatures(model, user));
var neighbours = CalculateKNearestNeighbours(svdBoostedKnnUser, model.Users, nearestNeighboursCount);
if (neighbours.Count == 0)
{
return(null);
}
return(RecommendationGenerator.GenerateRecommendations(svdBoostedKnnUser, neighbours, model, artists));
}
public float PredictRatingForArtist(IUser user, TSvdBoostedKnnModel model, List <IArtist> artists, int artistIndex, int nearestNeighboursCount)
{
var svdBoostedKnnUser = SvdBoostedKnnUser.FromIUser(user, NewUserFeatureGenerator.GetNewUserFeatures(model, user));
var neighbours = CalculateKNearestNeighbours(svdBoostedKnnUser, model.Users, nearestNeighboursCount);
if (neighbours.Count == 0)
{
return(1.0f);
}
return(RecommendationGenerator.PredictRatingForArtist(svdBoostedKnnUser, neighbours, model, artists, artistIndex));
}