public double userSimilarity(long userID1, long userID2)
{
DataModel model = base.getDataModel();
FastIDSet other = model.getItemIDsFromUser(userID1);
FastIDSet set2 = model.getItemIDsFromUser(userID2);
int num = other.size();
int num2 = set2.size();
if ((num == 0) && (num2 == 0))
{
return(double.NaN);
}
if ((num == 0) || (num2 == 0))
{
return(0.0);
}
int num3 = (num < num2) ? set2.intersectionSize(other) : other.intersectionSize(set2);
if (num3 == 0)
{
return(double.NaN);
}
int num4 = (num + num2) - num3;
return(((double)num3) / ((double)num4));
}
public double userSimilarity(long userID1, long userID2)
{
DataModel model = base.getDataModel();
FastIDSet other = model.getItemIDsFromUser(userID1);
FastIDSet set2 = model.getItemIDsFromUser(userID2);
int num = other.size();
int num2 = set2.size();
int intersection = (num < num2) ? set2.intersectionSize(other) : other.intersectionSize(set2);
return(doSimilarity(num, num2, intersection));
}
public override int getNumUsersWithPreferenceFor(long itemID1, long itemID2)
{
FastIDSet other = this.preferenceForItems.get(itemID1);
if (other == null)
{
return(0);
}
FastIDSet set2 = this.preferenceForItems.get(itemID2);
if (set2 == null)
{
return(0);
}
return((other.size() < set2.size()) ? set2.intersectionSize(other) : other.intersectionSize(set2));
}
public double userSimilarity(long userID1, long userID2)
{
DataModel model = base.getDataModel();
FastIDSet other = model.getItemIDsFromUser(userID1);
FastIDSet set2 = model.getItemIDsFromUser(userID2);
long num = other.size();
long num2 = set2.size();
long num3 = (num < num2) ? ((long)set2.intersectionSize(other)) : ((long)other.intersectionSize(set2));
if (num3 == 0L)
{
return(double.NaN);
}
long num4 = model.getNumItems();
double num5 = LogLikelihood.logLikelihoodRatio(num3, num2 - num3, num - num3, ((num4 - num) - num2) + num3);
return(1.0 - (1.0 / (1.0 + num5)));
}