public List <XY> RunClusterAlgo(int grxid, int gryid)
{
GlobalClass.program += "43. GridBaseCluster.RunClusterAlgo .. ";
// var clusterPoints = new List<XY>();
// params invalid
if (BaseDataset == null || BaseDataset.Count == 0 ||
grxid <= 0 || gryid <= 0)
{
return(clusterPoints);
}
// put points in buckets
foreach (var p in BaseDataset)
{
// find relative val
var relativeX = p.X - MinX;
var relativeY = p.Y - MinY;
int xid = (int)(relativeX / DeltaX);
int yid = (int)(relativeY / DeltaY);
// bucket id
string id = GetId(xid, yid);
// bucket exists, add point
if (BaseBucketsLookup.ContainsKey(id))
{
BaseBucketsLookup[id].Points.Add(p);
}
// new bucket, create and add point
else
{
Bucket bucket = new Bucket(xid, yid);
bucket.Points.Add(p);
BaseBucketsLookup.Add(id, bucket);
}
}
// calc centrod for all buckets
BaseSetCentroidForAllBuckets(BaseBucketsLookup.Values);
// merge if gridpoint is to close
MergeClustersGrid();
return(BaseGetClusterResult());
}
void MergeClustersGridHelper(string currentKey, string[] neighborKeys)
{
GlobalClass.program += "41. GridBaseCluster.MergeClustersGridHelper .. ";
double minDistX = DeltaX / 2.0;//heuristic, higher value gives less merging
double minDistY = DeltaY / 2.0;
//if clusters in grid are too close to each other, merge them
double minDist = MathTool.Max(minDistX, minDistY);
foreach (var neighborKey in neighborKeys)
{
if (!BaseBucketsLookup.ContainsKey(neighborKey))
{
continue;
}
var neighbor = BaseBucketsLookup[neighborKey];
if (neighbor.IsUsed == false)
{
continue;
}
var current = BaseBucketsLookup[currentKey];
var dist = MathTool.Distance(current.Centroid, neighbor.Centroid);
if (dist > minDist)
{
continue;
}
var centroidgroup = current.Centroid.CGroup;
foreach (var p in neighbor.Points)
{
//update CGroup
p.CGroup = centroidgroup;
}//end
neighP = neighbor.Points.ToArray();
current.Points.AddRange(neighbor.Points);//O(n)
// recalc centroid
var cp = BaseGetCentroidFromCluster(current.Points);
current.Centroid = cp;
neighbor.IsUsed = false; //merged, then not used anymore
}
}
void MergeClustersGridHelper(string currentKey, string[] neighborKeys)
{
double minDistX = DeltaX / 2.0; //heuristic, higher value gives less merging
double minDistY = DeltaY / 2.0;
//if clusters in grid are too close to each other, merge them
double minDist = MathTool.Max(minDistX, minDistY);
foreach (var neighborKey in neighborKeys)
{
if (!BaseBucketsLookup.ContainsKey(neighborKey))
{
continue;
}
var neighbor = BaseBucketsLookup[neighborKey];
if (neighbor.IsUsed == false)
{
continue;
}
var current = BaseBucketsLookup[currentKey];
var dist = MathTool.Distance(current.Centroid, neighbor.Centroid);
if (dist > minDist)
{
continue;
}
// merge
var color = current.Centroid.Color;
foreach (var p in neighbor.Points)
{
//update color
p.Color = color;
}
current.Points.AddRange(neighbor.Points); //O(n)
// recalc centroid
var cp = BaseGetCentroidFromCluster(current.Points);
current.Centroid = cp;
neighbor.IsUsed = false; //merged, then not used anymore
neighbor.Points.Clear(); //clear mem
}
}
public List <XY> RunClusterAlgo(int gridx, int gridy)
{
// params invalid
if (gridx <= 0 || gridy <= 0)
{
throw new ApplicationException("GridCluster.RunClusterAlgo gridx or gridy is <= 0");
}
// put points in buckets
foreach (var p in BaseDataset)
{
// find relative val
var relativeX = p.X - MinX;
var relativeY = p.Y - MinY;
int idx = (int)(relativeX / DeltaX);
int idy = (int)(relativeY / DeltaY);
// bucket id
string id = GetId(idx, idy);
// bucket exists, add point
if (BaseBucketsLookup.ContainsKey(id))
{
BaseBucketsLookup[id].Points.Add(p);
}
// new bucket, create and add point
else
{
Bucket bucket = new Bucket(idx, idy);
bucket.Points.Add(p);
BaseBucketsLookup.Add(id, bucket);
}
}
// calc centrod for all buckets
BaseSetCentroidForAllBuckets(BaseBucketsLookup.Values);
// merge if gridpoint is to close
if (DoMergeGridIfCentroidsAreCloseToEachOther)
{
MergeClustersGrid();
}
if (DoUpdateAllCentroidsToNearestContainingPoint)
{
BaseUpdateAllCentroidsToNearestContainingPoint();
}
// check again
// merge if gridpoint is to close
if (DoMergeGridIfCentroidsAreCloseToEachOther &&
DoUpdateAllCentroidsToNearestContainingPoint)
{
MergeClustersGrid();
// and again set centroid to closest point in bucket
BaseUpdateAllCentroidsToNearestContainingPoint();
}
return(BaseGetClusterResult());
}