/// <summary>Compute similarity between one item and a collection of items</summary>
/// <param name="item_id">the item ID</param>
/// <param name="items">a collection of items</param>
/// <param name="distances">the distance measure to use</param>
/// <returns>the similarity between the item and the collection</returns>
public static double Diversity(int item_id, ICollection<int> items, EuclideanMatrix distances)
{
double diversity = 0;
foreach (int other_item_id in items){
//Console.WriteLine (other_item_id);
//Console.WriteLine ("item: " + distances [item_id-1, other_item_id-1]);
diversity += distances [item_id-1, other_item_id-1];
}
return (double) diversity;
}
/// <summary>Constructor</summary>
/// <param name="item_correlation">the similarity measure to use for diversification</param>
public LatentFeatureDiversfication(EuclideanMatrix distances)
{
Distances = distances;
}