public UserItem(User user, Item item)
: this()
{
User = user;
Item = item;
}
public UserItem(string userId, string itemId)
: this()
{
User = new User(userId);
Item = new Item(itemId);
}
public PositiveFeedback(User user, Item item)
: base(user, item)
{
}
public ItemRating(User user, Item item, float rating)
: base(user, item)
{
Rating = rating;
Domain = CrossDomainDataContainer.GetDefualtDomain();
}
private string BuildUserCrossDomainFeatureVector(User user)
{
string extendedVector = "";
Func<ItemRating, bool> checkActivation = r => r.Domain.IsActive == true; //r.IsActive == true;
var domainRatings = user.Ratings.Where(checkActivation).GroupBy(r => r.Domain.Id);
int userAuxDomains = user.Ratings.Select(r => r.Domain.Id).Distinct().Where(d => d != TargetDomain.Id).Count();
int perDomainRatings;
if (userAuxDomains > 0)
perDomainRatings = (int)Math.Ceiling((double)NumAuxRatings / userAuxDomains);
else
perDomainRatings = 0;
var avgUserRating = user.Ratings.Average(r => r.Rating);
int take = perDomainRatings;
int remain = NumAuxRatings;
foreach (var d in domainRatings)
{
if (d.Key != TargetDomain.Id)
{
int ratingCount = d.Count();
string domainExtendedVector = "";
var ratings = d.OrderByDescending(r => r.Item.Ratings.Count).Take(take);
if (ratings.Count() > 0)
{
domainExtendedVector = ratings
.Select(dr => string.Format("{0}:{1:0.0000}", Mapper.ToInternalID(dr.Item.Id), (double)(dr.Rating - avgUserRating) / 4 + 1)) // dr.Rating / ratingCount))
.Aggregate((cur, next) => cur + " " + next);
}
if (!String.IsNullOrEmpty(domainExtendedVector.TrimEnd(' ')))
extendedVector += " " + domainExtendedVector;
remain = remain - perDomainRatings;
if (remain > 0)
take = perDomainRatings;
else
take = 0;
}
}
return extendedVector;
}
public ItemRating CreateItemRating(string relationId, double? timestamp, string properties, string linkedEntities)
{
var ir = new ItemRating();
ir.Id = relationId;
ir.Timestamp = timestamp;
var jProperties = JObject.Parse(properties);
// add general properties
jProperties.Properties().ToList().ForEach(p => ir.AddProperty(p.Name, p.Value.ToString()));
// try to extract rating from properties
try
{
ir.Rating = float.Parse(jProperties["rating"].ToString());
}
catch (Exception)
{
throw new Exception("Can not find / parse rating in the relation.");
}
// parse linked entities
var jLinkedEntities = JObject.Parse(linkedEntities);
// user
string user = jLinkedEntities["subject"].ToString();
if (!user.Contains("user"))
throw new Exception("Expect subject of type user in the linked entities.");
string userId = user.Substring(user.IndexOf(':') + 1);
User u;
if (!Users.TryGetValue(userId, out u))
{
Console.WriteLine(string.Format("User with id {0} is not defined in the entities file.", userId));
u = new User(userId);
}
u.Ratings.Add(ir);
// item
string item = jLinkedEntities["object"].ToString();
if (!item.Contains("movie") && !item.Contains("item"))
throw new Exception("Expect object of type movie or item in the linked entities.");
string itemId = item.Substring(item.IndexOf(':') + 1);
Item i;
if (!Items.TryGetValue(itemId, out i))
{
Console.WriteLine(string.Format("Item with id {0} is not defined in the entities file.", itemId));
i = new Item(itemId);
}
i.Ratings.Add(ir);
ir.User = u;
ir.Item = i;
return ir;
}
public User CreateUser(string userId, double? timestamp, string properties)
{
var u = new User(userId);
u.Timestamp = timestamp;
var jObject = JObject.Parse(properties);
jObject.Properties().ToList().ForEach(p => u.AddProperty(p.Name, p.Value.ToString()));
return u;
}