public double CalculateDistance(IDistribution <T> obj1, IDistribution <T> obj2)
{
Func <Dictionary <T, int>, T, int, int> getRankOrDefault =
(rankedDistribution, event_, defaultRank) =>
{
int rank;
if (rankedDistribution.TryGetValue(event_, out rank) == false)
{
rank = defaultRank;
}
return(rank);
};
var rankedDistribution1 = obj1.OrderByDescending <KeyValuePair <T, long>, long>(e => e.Value).Select((e, i) => new { event_ = e.Key, rank = i + 1 }).ToDictionary(p => p.event_, p => p.rank);
var rankedDistribution2 = obj2.OrderByDescending <KeyValuePair <T, long>, long>(e => e.Value).Select((e, i) => new { event_ = e.Key, rank = i + 1 }).ToDictionary(p => p.event_, p => p.rank);
// todo: 400 is hardcoded!
int distance =
obj1.DistinctRepresentedEvents
.Union(obj2.DistinctRepresentedEvents)
.Select(
e =>
Math.Abs(getRankOrDefault(rankedDistribution1, e, 400) -
getRankOrDefault(rankedDistribution2, e, 400)))
.Sum();
return(distance);
}
private static IDictionary <T, int> GetRankedLanguageModel(IDistribution <T> languageModel)
{
Dictionary <T, int> rankedLanguageModel = languageModel.OrderByDescending <KeyValuePair <T, long>, long>(e => e.Value).Select((e, i) => new { event_ = e.Key, rank = i + 1 }).ToDictionary(p => p.event_, p => p.rank);
return(rankedLanguageModel);
}