/// <summary>
/// Get the minimum distance between two clusters
/// </summary>
/// <param name="a">Cluster A</param>
/// <param name="b">Cluster B</param>
/// <returns>Minimum straight-line distance between the two clusters of points</returns>
public static double GetMinDistance(Cluster a, Cluster b)
{
// Compute all distances
List<double> distances = new List<double>();
foreach (Point3D pointA in a.points)
{
foreach (Point3D pointB in b.points)
{
distances.Add(pointA.DistanceTo(pointB));
}
}
return distances.Min();
}
private void WorkerOnDoWork(object sender, DoWorkEventArgs doWorkEventArgs)
{
// Prepare the output file path
string outputPath = Path.GetDirectoryName(this.InputFile);
string outputName = Path.GetFileNameWithoutExtension(this.InputFile) + ".cluster";
string outputFile = Path.Combine(outputPath, outputName);
// Load the points
List<Point3D> rawPoints = LoadPointsFromFile(this.InputFile);
// Collapse the points to the central Z
var pointZValues = from x in rawPoints select x.Z;
double centralZ = (pointZValues.Max() + pointZValues.Min())/2.0;
List<Point3D> freePoints = (from x in rawPoints select new Point3D(x.X, x.Y, centralZ)).ToList();
// Begin the clustering!
List<Cluster> clusters = (from x in freePoints select new Cluster(x)).ToList();
bool action = true;
int iteration = 0;
int merges = 0;
double toleranceInMeters = this.Tolerance/100.0;
while (action)
{
action = false;
// Iterate through all of the clusters, checking each one against all of the other clusters to see
// if any valid merges can be made.
for (int i = 0; i < clusters.Count; i++)
{
// We start with an empty list of valid merges. As we go through the clusters will we check each one for
// clusters that are below the minimum tolerance distance and add them to the list of valid merges. When
// we have finished going through the clusters we will see if there are any valid merges, and if there are
// we will perform the merges and construct a new list of clusters, beginning the process again.
List<int> validMerges = new List<int>();
for (int j = 0; j < clusters.Count; j++)
{
if (i == j)
continue;
if (Cluster.GetMinDistance(clusters[i], clusters[j]) < toleranceInMeters)
{
validMerges.Add(j);
}
}
// If there are valid merges we must now perform them.
if (validMerges.Any())
{
merges += validMerges.Count;
validMerges.Add(i);
var clustersToMerge = from x in validMerges select clusters[x];
Cluster merged = new Cluster(clustersToMerge);
// Construct the new list of clusters without any of the ones that were merged
List<Cluster> newClusterList = new List<Cluster> {merged};
// Now add every cluster after i
for (int j = i; j < clusters.Count; j++)
{
if (!validMerges.Contains(j))
newClusterList.Add(clusters[j]);
}
// Now add every cluster before i, which presumably has no merges
for (int j = 0; j < i; j++)
{
if (!validMerges.Contains(j))
newClusterList.Add(clusters[j]);
}
clusters = newClusterList;
action = true;
break;
}
}
// Count the total points
int totalPoints = 0;
foreach (var cluster in clusters)
{
totalPoints += cluster.Count;
}
iteration++;
string updateText = string.Format("Clusters: {0}, Merges: {1}, Total Points: {3}, Iteration {2}", clusters.Count, merges, iteration, totalPoints);
WorkerOnProgressChanged(sender, new ProgressChangedEventArgs(0, updateText));
}
File.WriteAllText(outputFile, JsonConvert.SerializeObject(clusters, Formatting.Indented));
}
/// <summary>
/// Create a cluster from the merge of two clusters
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
public Cluster(Cluster a, Cluster b)
{
this.points = new List<Point3D>();
this.points.AddRange(a.points);
this.points.AddRange(b.points);
}