public static ClusterObject Create(string rawData)
{
ClusterObject newClusterObject = new ClusterObject();
string[] coordList = rawData.Split(" ".ToCharArray());
foreach (string coord in coordList)
{
newClusterObject.Coordinates.Add(Double.Parse(coord));
}
return newClusterObject;
}
public override double CalculateDistance(ClusterObject obj1, ClusterObject obj2)
{
double dDistance = 0;
double dTemp = 0;
for (int i = 0; i < obj1.Coordinates.Count; i++)
{
dTemp += Math.Pow((obj2.Coordinates[i] - obj1.Coordinates[i]), 2);
}
dDistance = Math.Sqrt(dTemp);
return dDistance;
}
public void UpdateClusterMeans()
{
ClusterObject newCentroid = new ClusterObject();
double[] newCoordinates = new double[m_nDimensionCount];
foreach (KeyValuePair<int, ClusterObject> kvp in m_dictObjects)
{
for (int i = 0; i < m_nDimensionCount; i++)
{
newCoordinates[i] += kvp.Value.Coordinates[i];
}
}
for (int i = 0; i < m_nDimensionCount; i++)
{
newCoordinates[i] /= m_dictObjects.Count;
}
newCentroid.Coordinates = new List<double>(newCoordinates);
if (m_OldClusterCentroid == null)
{
m_OldClusterCentroid = newCentroid;
}
else
{
m_OldClusterCentroid = m_ClusterCentroid;
}
m_ClusterCentroid = newCentroid;
EuclidianDistanceStrategy e = new EuclidianDistanceStrategy();
double dDistance = e.CalculateDistance(m_OldClusterCentroid, m_ClusterCentroid);
if (dDistance > 0) //TODO: Set an acceptable margin to determine if the
// center moved or not. To aviod osciallation, small changes
// may be neglected.
{
CenterMoved = true;
}
else
{
CenterMoved = false;
}
}
public void AddObject(int rowId, ClusterObject newObject)
{
m_dictObjects.Add(rowId, newObject);
m_nDimensionCount = newObject.Coordinates.Count;
}
public static double CalculateDistance(ClusterObject object1, ClusterObject object2)
{
EuclidianDistanceStrategy distance = new EuclidianDistanceStrategy();
return distance.CalculateDistance(object1, object2);
}
abstract public double CalculateDistance(ClusterObject obj1, ClusterObject obj2);
private Cluster FindClosestCluster(ClusterObject clusterObject)
{
Trace.WriteLineIf(SystemDefinitions.ErrSev.TraceVerbose, HelperMethods.GenerateLogLine("Find closest cluster to object : " + clusterObject.ToString()));
double[] distances = new double[K];
Cluster closestCluster = null;
for (int i = 0; i < clusters.Length; i++)
{
distances[i] = ClusterObject.CalculateDistance(clusterObject, clusters[i].ClusterCentroid);
Trace.WriteLineIf(SystemDefinitions.ErrSev.TraceVerbose, HelperMethods.GenerateLogLine(String.Format("Distance for cluster [{0}] = {1}", i, distances[i])));
}
int nSmallestDistanceIndex = 0;
double dSmallestDistance = Double.MaxValue;
for (int i = 0; i < distances.Length; i++)
{
if (distances[i] < dSmallestDistance)
{
dSmallestDistance = distances[i];
nSmallestDistanceIndex = i;
}
}
closestCluster = clusters[nSmallestDistanceIndex];
Trace.WriteLineIf(SystemDefinitions.ErrSev.TraceVerbose, HelperMethods.GenerateLogLine(String.Format("Closest cluster : [{0}] ", nSmallestDistanceIndex)));
return closestCluster;
}
public override double CalculateDistance(ClusterObject obj1, ClusterObject obj2)
{
throw new NotImplementedException();
}