public bool Step()
{
var prevIteration = State.Iterations.Last();
if (prevIteration.Clusters.Count <= 1)
{
return(false);
}
if (MinClusters > 0 && prevIteration.Clusters.Count <= MinClusters)
{
return(false);
}
if (DistanceLimit > 0 && prevIteration.ClosestPair.Distance >= DistanceLimit)
{
return(false);
}
HCCluster clusterI = prevIteration.ClosestPair.I;
HCCluster clusterJ = prevIteration.ClosestPair.J;
HCCluster joinedCluster = HCCluster.Join(clusterI, clusterJ);
List <HCCluster> newClusters = new();
foreach (HCCluster oldCluster in prevIteration.Clusters)
{
if (oldCluster != clusterI && oldCluster != clusterJ)
{
newClusters.Add(oldCluster);
}
}
var closest = distanceMatrix.FindClosestPair(
clusterPairs: joinedCluster.PairsWith(newClusters),
metric: (joinedCluster, other) => distanceMatrix.LanceWillamsSingleLinkage(clusterI, clusterJ, other)
);
newClusters.Add(joinedCluster);
if (closest.Distance > prevIteration.ClosestPair.Distance)
{
closest = distanceMatrix.FindClosestPair(
clusterPairs: HCCluster.AllPairs(newClusters),
metric: distanceMatrix.GetDistance
);
}
State.Iterations.Add(new HCIteration(
clusters: newClusters,
closestPair: closest
));
return(true);
}
