/// <p>
/// Thanks to tsmorton for suggesting this functionality and writing part of the code.
/// </p>
///
/// @see GenericItemSimilarity#GenericItemSimilarity(Iterable, int)
/// @see GenericItemSimilarity#GenericItemSimilarity(NReco.CF.Taste.Similarity.ItemSimilarity,
/// NReco.CF.Taste.Model.DataModel, int)
public static List <GenericItemSimilarity.ItemItemSimilarity> GetTopItemItemSimilarities(
int howMany, IEnumerator <GenericItemSimilarity.ItemItemSimilarity> allSimilarities)
{
var topSimilarities
= new SortedSet <GenericItemSimilarity.ItemItemSimilarity>();
bool full = false;
double lowestTopValue = Double.NegativeInfinity;
while (allSimilarities.MoveNext())
{
GenericItemSimilarity.ItemItemSimilarity similarity = allSimilarities.Current;
double value = similarity.getValue();
if (!Double.IsNaN(value) && (!full || value > lowestTopValue))
{
topSimilarities.Add(similarity);
if (full)
{
topSimilarities.Remove(topSimilarities.Max); //poll();
}
else if (topSimilarities.Count > howMany)
{
full = true;
topSimilarities.Remove(topSimilarities.Max);//topSimilarities.poll();
}
lowestTopValue = topSimilarities.Max.getValue();
}
}
int size = topSimilarities.Count;
var result = new List <GenericItemSimilarity.ItemItemSimilarity>(size);
result.AddRange(topSimilarities);
return(result);
}
public static List <GenericItemSimilarity.ItemItemSimilarity> getTopItemItemSimilarities(int howMany, IEnumerator <GenericItemSimilarity.ItemItemSimilarity> allSimilarities)
{
SortedSet <GenericItemSimilarity.ItemItemSimilarity> collection = new SortedSet <GenericItemSimilarity.ItemItemSimilarity>();
bool flag = false;
double negativeInfinity = double.NegativeInfinity;
while (allSimilarities.MoveNext())
{
GenericItemSimilarity.ItemItemSimilarity current = allSimilarities.Current;
double d = current.getValue();
if (!double.IsNaN(d) && (!flag || (d > negativeInfinity)))
{
collection.Add(current);
if (flag)
{
collection.Remove(collection.Max);
}
else if (collection.Count > howMany)
{
flag = true;
collection.Remove(collection.Max);
}
negativeInfinity = collection.Max.getValue();
}
}
List <GenericItemSimilarity.ItemItemSimilarity> list = new List <GenericItemSimilarity.ItemItemSimilarity>(collection.Count);
list.AddRange(collection);
return(list);
}
