/// <summary>
/// конструктор алгоритма
/// </summary>
/// <param name="xDist">distance function for input data space</param>
/// <param name="yDist">distance function for preprocessed data space</param>
/// <param name="xyConv">space conversion function (in some cases could be similar to feature mapping)</param>
/// <param name="comparePointFunction">nearest neihbor function for clusters, shoud return constant -1 to be trivial</param>
/// <param name="clusterFusionCriteria">similarity function to define cluster fusion, should return constant -1 to be trivial</param>
/// <param name="clusterDivider">a function for spliting cluster in two, should return empty collection of clusters to be trivial</param>
/// <param name="clusterSortCriteria">a function for cluster comparing</param>
/// <param name="cnt">cluster center function</param>
public ClusterAlgorithm(distanceFunction xDist, distanceFunction yDist, spaceConversionFunction xyConv, sameCluster comparePointFunction,
similarClusters clusterFusionCriteria, splitCluster clusterDivider, comapreClusters clusterSortCriteria, clusterCenterFunction cnt, bool isSplitTrivial = false)
{
this.xDist = xDist;
this.yDist = yDist;
this.xyConv = xyConv;
this.comparePointFunction = comparePointFunction;
this.clusterFusionCriteria = clusterFusionCriteria;
this.clusterDivider = clusterDivider;
this.clusterSortCriteria = clusterSortCriteria;
this.cntFunc = cnt;
this.isSplitingTrivial = isSplitTrivial;
}
public static float ComapreClustersBySize(Cluster k1, Cluster k2, distanceFunction yDist, clusterCenterFunction cnf, double[] cnfPars)
{
return(k1.Size - k2.Size);
}
public static ICollection <Cluster> SplitClusterGraph(Cluster k1, distanceFunction yDist, clusterCenterFunction cnf, double[] cnfPars, double[] splitPars)
{
List <Edge> edges = new List <Edge>(GetEdgesForCluster(k1, yDist));
List <int> inds = new List <int>();
for (int i = 0; i < k1.Size; i++)
{
inds.Add(i);
}
for (int i = 0; i < edges.Count; i++)
{
if (edges[i].Distance > splitPars[0])
{
edges.RemoveAt(i);
i--;
}
}
List <ICollection <int> > components = new List <ICollection <int> >(GetLinkedComponents(edges, inds));
List <Cluster> res = new List <Cluster>();
for (int i = 0; i < components.Count; i++)
{
List <double[]> data = new List <double[]>();
List <int> gInds = new List <int>();
for (int j = 0; j < components[i].Count; j++)
{
data.Add(k1.GetElementByLocalIndex(components[i].ElementAt(j)));
gInds.Add(k1.GetGlobalIndexByLocal(components[i].ElementAt(j)));
}
res.Add(new Cluster(gInds.ToArray(), data));
}
return(res);
}
public static ICollection <Cluster> SplitClusterTrivial(Cluster k1, distanceFunction yDist, clusterCenterFunction cnf, double[] cnfPars, double[] splitPars)
{
return(new Cluster[] { k1 });
}
public static float SimilarClusterBrute(Cluster y1, Cluster y2, distanceFunction yDist, clusterCenterFunction cnf, double[] cnfPars)
{
double[] center1 = cnf(y1, yDist, cnfPars), center2 = cnf(y2, yDist, cnfPars);
double max1 = yDist(center1, y1.GetElementByLocalIndex(0)), max2 = yDist(center2, y2.GetElementByLocalIndex(0));
double tmpDist;
for (int i = 0; i < y1.Size; i++)
{
tmpDist = yDist(y1.GetElementByLocalIndex(i), center1);
if (tmpDist > max1)
{
max1 = tmpDist;
}
}
for (int i = 0; i < y2.Size; i++)
{
tmpDist = yDist(y2.GetElementByLocalIndex(i), center2);
if (tmpDist > max2)
{
max2 = tmpDist;
}
}
double cDist = yDist(center1, center2);
double maxAvg = (max1 + max2) / 2;
if (cDist < maxAvg)
{
return(1.0f);
}
else
{
return((float)maxAvg / (float)cDist);
}
}
public static float SameClusterBrute(Cluster y1, Cluster y2, distanceFunction yDist, clusterCenterFunction cnf, double[] cnfPars)
{
double[] center1 = cnf(y1, yDist, cnfPars), center2 = cnf(y2, yDist, cnfPars);
double max1 = yDist(center1, y1.GetElementByLocalIndex(0)), max2 = yDist(center2, y2.GetElementByLocalIndex(0));
double tmpDist;
for (int i = 0; i < y1.Size; i++)
{
tmpDist = yDist(y1.GetElementByLocalIndex(i), center1);
if (tmpDist > max1)
{
max1 = tmpDist;
}
}
for (int i = 0; i < y2.Size; i++)
{
tmpDist = yDist(y2.GetElementByLocalIndex(i), center2);
if (tmpDist > max2)
{
max2 = tmpDist;
}
}
int counter1 = 0, counter2 = 0;
for (int i = 0; i < y1.Size; i++)
{
tmpDist = yDist(y1.GetElementByLocalIndex(i), center2);
if (tmpDist < max1)
{
counter1++;
}
}
for (int i = 0; i < y2.Size; i++)
{
tmpDist = yDist(y2.GetElementByLocalIndex(i), center1);
if (tmpDist < max2)
{
counter2++;
}
}
//подсчёт
float pre1 = ((float)counter1) / y1.Size, pre2 = ((float)counter2) / y2.Size;
return(pre1 * pre2);
}
