/// <summary>
/// Given an instance to classify, scores and returns
/// score by class.
/// </summary>
/// <remarks>
/// Given an instance to classify, scores and returns
/// score by class.
/// NOTE: supports only RVFDatums
/// </remarks>
public virtual ClassicCounter <K> ScoresOf(IDatum <K, V> datum)
{
if (datum is RVFDatum <object, object> )
{
RVFDatum <K, V> vec = (RVFDatum <K, V>)datum;
if (l2Normalize)
{
ClassicCounter <V> featVec = new ClassicCounter <V>(vec.AsFeaturesCounter());
Counters.Normalize(featVec);
vec = new RVFDatum <K, V>(featVec);
}
ClassicCounter <ICounter <V> > scores = new ClassicCounter <ICounter <V> >();
foreach (ICounter <V> instance in instances.AllValues())
{
scores.SetCount(instance, Counters.Cosine(vec.AsFeaturesCounter(), instance));
}
// set entry, for given instance and score
IList <ICounter <V> > sorted = Counters.ToSortedList(scores);
ClassicCounter <K> classScores = new ClassicCounter <K>();
for (int i = 0; i < k && i < sorted.Count; i++)
{
K label = classLookup[sorted[i]];
double count = 1.0;
if (weightedVotes)
{
count = scores.GetCount(sorted[i]);
}
classScores.IncrementCount(label, count);
}
return(classScores);
}
else
{
return(null);
}
}