/// <summary>
/// Инициализация начальных кластеров
/// </summary>
/// <param name="points">Исходные точки</param>
/// <returns>Кластера с дополнительной информацией <seealso cref="CalculatedCluster"/></returns>
private Dictionary <Guid, CalculatedCluster> InitClusters(IEnumerable <CurePoint> points)
{
var clusters = points.Select(x => new CureCluster(x)).ToList();
var dict = new Dictionary <Guid, CalculatedCluster>();
foreach (var cluster1 in clusters)
{
var minDistance = Double.MaxValue;
CureCluster closest = null;
foreach (var cluster2 in clusters)
{
if (cluster1 == cluster2)
{
continue;
}
var distance = Distance(cluster1, cluster2);
if (distance < minDistance)
{
minDistance = distance;
closest = cluster2;
}
}
dict.Add(cluster1.Number, new CalculatedCluster {
Closest = closest, Cluster = cluster1, Distance = minDistance
});
}
return(dict);
}
/// <summary>
/// Слияние кластеров
/// </summary>
/// <param name="cluster1">Кластер№1</param>
/// <param name="cluster2">Кластер№2</param>
/// <returns>Итоговый кластер</returns>
private CureCluster MergeClusters(CureCluster cluster1, CureCluster cluster2)
{
var totalPoints = cluster1.Points.Union(cluster2.Points).ToList();
var meanPoint = new double[totalPoints.First().Vector.Length];
for (var i = 0; i < meanPoint.Length; ++i)
{
meanPoint[i] = totalPoints.Sum(x => x.Vector[i]) / totalPoints.Count * 1.0;
}
var ordered = totalPoints
.Select(x => new
{
Point = x,
Distance = _distanceCalculator.GetDistance(meanPoint, x.Vector)
})
.OrderBy(x => x.Distance).ToList();
var rep = (_c > ordered.Count ? ordered : ordered.Take(_c))
.Select(x => x.Point.Vector.Select((v, i) => v + _a * (meanPoint[i] - v)).ToArray())
.ToList();
return(new CureCluster(totalPoints, rep));
}
/// <summary>
/// Перерасчет метрки кластеров для определенного кластера с номером
/// </summary>
/// <param name="clusters">Кластеры</param>
/// <param name="number">Номер кластера</param>
private void RecalculateClosest(Dictionary <Guid, CalculatedCluster> clusters, Guid number)
{
var minDistance = Double.MaxValue;
CureCluster closest = null;
foreach (var pair in clusters)
{
if (pair.Key == number)
{
continue;
}
var distance = Distance(pair.Value.Cluster, clusters[number].Cluster);
if (distance < minDistance)
{
minDistance = distance;
closest = pair.Value.Cluster;
}
}
clusters[number].Closest = closest;
clusters[number].Distance = minDistance;
}
/// <summary>
/// Расчет растояния между двумя кластерами
/// </summary>
/// <param name="cluster1">Калстер№1</param>
/// <param name="cluster2">Кластер№2</param>
/// <returns>Расстояние</returns>
public double Distance(CureCluster cluster1, CureCluster cluster2)
{
var repPoints = cluster2.RepPoints.ToList();
var min = _distanceCalculator.GetDistance(cluster1.RepPoints.First(), repPoints.First());
foreach (var repPoint1 in cluster1.RepPoints)
{
foreach (var repPoint2 in repPoints)
{
var distance = _distanceCalculator.GetDistance(repPoint1, repPoint2);
if (distance < min)
{
min = distance;
}
}
}
var maxWeights = Math.Max(cluster1.Points.Sum(x => x.Weight), cluster2.Points.Sum(x => x.Weight));
return(maxWeights > _averageCount ? (min * maxWeights * _targetClustersCount / _averageCount) : min);
}
