public double EvaluateScoreForUSer(int userId, ISettings settings)
{
_helpers.SaveSettings(settings.Id);
var users = _selector.SelectUsersIdsToCompareWith(userId);
var similarUsers = _nearestNeighbors.GetNearestNeighbors(userId, users, settings);
var scores = _recommender.PredictScoreForAllUsersBooks(similarUsers, userId);
_helpers.PersistSimilarUsersInDb(similarUsers, settings.Id);
_helpers.PersistTestResult(scores, settings.Id);
return(EvaluatePredictionsUsingRSME(scores));
}
public void EvaluateScoreForUSer_ShouldComputeError(double[] predicted, short[] actual,
double error)
{
const int userId = 1;
var scores = _testHelpers.CreateBookScores(userId, new[] { "1", "2", "3" }, actual, predicted).ToList();
var users = new List <int> {
};
var similarUsers = new List <UsersSimilarity>();
_selector.SelectUsersIdsToCompareWith(userId).Returns(users);
_nearestNeighbors.GetNearestNeighbors(userId, users, _settings).Returns(similarUsers);
_recommender.PredictScoreForAllUsersBooks(similarUsers, userId).Returns(scores);
_sut.EvaluateScoreForUSer(userId, _settings).ShouldBe(error);
_cfHelpers.Received().PersistSimilarUsersInDb(similarUsers, _settings.Id);
_cfHelpers.Received().PersistTestResult(scores, _settings.Id);
_cfHelpers.Received().SaveSettings(_settings.Id);
}
public Book[] RecommendBooksForUser(int userId, ISettings settings)
{
// get from db by default
var books = _recommender.GetRecommendedBooksFromDatabase(userId);
if (books.Length != 0)
{
return(books);
}
var users = _selector.SelectUsersIdsToCompareWith(userId);
var similarUsers = _nearestNeighbors.GetNearestNeighbors(userId, users, settings);
return(_recommender.GetRecommendedBooks(similarUsers, userId));
}
