public List <UsersSimilarity> CreateUserSimilarities(ISettings settings,
int userId,
List <int> comparedUserId,
BookScore[] userBooks,
List <BookScore[]> comparedUserBooks,
List <double?> similarity = null)
{
var userSimilarities = new List <UsersSimilarity>();
var comparer = new BookScoreEqualityComparer();
for (int i = 0; i < comparedUserId.Count; i++)
{
var comparedUserRatesForMutualBooks = comparedUserBooks[i].Intersect(userBooks, comparer).ToArray();
var userRatesForMutualBooks = userBooks.Intersect(comparedUserBooks[i], comparer).ToArray();
var booksUniqueForComparedUser = comparedUserBooks[i].Except(userBooks, comparer).ToArray();
var temp = new UsersSimilarity
{
AverageScoreForComparedUser = RandomNumber(3),
ComparedUserId = comparedUserId[i],
UserId = userId,
Similarity = similarity?[i],
SimilarityType = (int)settings.SimilarityDistance,
ComparedUserRatesForMutualBooks = comparedUserRatesForMutualBooks,
BooksUniqueForComparedUser = booksUniqueForComparedUser,
UserRatesForMutualBooks = userRatesForMutualBooks
};
userSimilarities.Add(temp);
}
return(userSimilarities);
}
public UsersSimilarity SelectMutualAndUniqueBooksForUsers(int userId, int comparedUserId)
{
var books1 = _context.GetBooksRatesByUserId(userId);
var books2 = _context.GetBooksRatesByUserId(comparedUserId);
var comparer = new BookScoreEqualityComparer();
var userRatesForMutualBooks = books1.Intersect(books2, comparer).ToArray();
if (userRatesForMutualBooks.Length == 0)
{
return(null);
}
var comparedUserRatesForMutualBooks = books2.Intersect(books1, comparer).ToArray();
var uniqueBooksForComparedUser = books2.Except(books1, comparer).ToArray();
return(new UsersSimilarity
{
BooksUniqueForComparedUser = uniqueBooksForComparedUser,
UserRatesForMutualBooks = userRatesForMutualBooks,
ComparedUserRatesForMutualBooks = comparedUserRatesForMutualBooks,
UserId = userId,
ComparedUserId = comparedUserId,
AverageScoreForComparedUser = _context.GetAverageRateForUser(comparedUserId),
});
}
