public static List <T> GetClusterCenters(List <T> points, T nilValue, double radius)
{
try
{
//var result = new KdTreePointClusters<T>();
Func <T, T, int> xWise = (p1, p2) => p1.X.CompareTo(p2.X);
Func <T, T, int> yWise = (p1, p2) => p1.Y.CompareTo(p2.Y);
Func <T, T, int>[] funcs = { xWise, yWise };
HashSet <T> set = new HashSet <T>();
var kdtree = new BalancedKdTree <T>(points, funcs.ToList(), nilValue, i => i);
if (!(points?.Count > 0))
{
return(new List <T>());
}
List <T> result = new List <T>();
for (int i = 0; i < points.Count; i++)
{
try
{
if (set.Contains(points[i]))
{
continue;
}
result.Add(points[i]);
var neighbours = kdtree.FindNeighbours(points[i], radius);
set.Add(points[i]);
set.UnionWith(neighbours);
//for (int j = 0; j < neighbours?.Count; j++)
//{
// set.Add(neighbours[j]);
//}
}
catch (Exception ex)
{
return(new List <T>());
}
}
return(result);
}
catch (Exception ex)
{
return(new List <T>());
}
}
public void TestNearestNeighbour()
{
List <Point> points = new List <Point>();
points.Add(new Point(1, 9));
points.Add(new Point(2, 2));
points.Add(new Point(2, 5));
points.Add(new Point(2, 10));
points.Add(new Point(2, 12));
points.Add(new Point(3, 7));
points.Add(new Point(4, 11));
points.Add(new Point(5, 8));
points.Add(new Point(6, 7));
points.Add(new Point(7, 3));
points.Add(new Point(7, 4));
points.Add(new Point(7, 5));
points.Add(new Point(7, 11));
points.Add(new Point(8, 3));
points.Add(new Point(8, 4));
points.Add(new Point(8, 5));
points.Add(new Point(9, 3));
points.Add(new Point(9, 4));
points.Add(new Point(9, 5));
points.Add(new Point(9, 10));
points.Add(new Point(9, 11));
points.Add(new Point(10, 3));
points.Add(new Point(10, 10));
points.Add(new Point(10, 11));
points.Add(new Point(11, 6));
Func <Point, Point, int> xWise = (p1, p2) => p1.X.CompareTo(p2.X);
Func <Point, Point, int> yWise = (p1, p2) => p1.Y.CompareTo(p2.Y);
Func <Point, Point, int>[] funcs = { xWise, yWise };
var kdtree = new BalancedKdTree <Point>(points.ToArray(), funcs.ToList(), Point.NaN, i => i);
Assert.AreEqual(new Point(6, 7), kdtree.FindNearestNeighbour(new Point(7, 7)));
Assert.AreEqual(new Point(7, 4), kdtree.FindNearestNeighbour(new Point(7, 4)));
Assert.AreEqual(new Point(11, 6), kdtree.FindNearestNeighbour(new Point(10, 6)));
Assert.AreEqual(new Point(4, 11), kdtree.FindNearestNeighbour(new Point(3, 11)));
for (int i = 0; i < 100; i++)
{
var point = new Point(Math.Sin(RandomHelper.Get(0, 100)) * 20,
Math.Cos(RandomHelper.Get(0, 100)) * 20);
System.Diagnostics.Debug.WriteLine(point.ToString());
Assert.AreEqual(kdtree.FindNearestNeighbour(point), FindNearestBruteForce(points, point));
}
}
public void GetClusters(Func <T, T, bool> groupLogic)
{
Func <Group <T>, Group <T>, int> xWise = (p1, p2) => p1.Center.X.CompareTo(p2.Center.X);
Func <Group <T>, Group <T>, int> yWise = (p1, p2) => p1.Center.Y.CompareTo(p2.Center.Y);
Func <Group <T>, Group <T>, int>[] funcs = { xWise, yWise };
//this.Groups = new List<Group<T>>();
if (_allSingleMembers?.Count > 0)
{
this.Groups = new BalancedKdTree <Group <T> >(new Group <T>[] { new Group <T>(_allSingleMembers[0]) }, funcs.ToList(), _nilValue, g => g.Center);
//Groups.Add(new Group<T>(_allSingleMembers[0]));
for (int i = 1; i < _allSingleMembers.Count; i++)
{
bool hasGroup = false;
var tempGroup = new Group <T>(_allSingleMembers[i]);
var nearestGroup = Groups.FindNearestNeighbour(tempGroup, ((g1, g2) => g1.Center.DistanceTo(g2.Center)));
if (groupLogic(nearestGroup.Center, _allSingleMembers[i]))
{
nearestGroup.Add(_allSingleMembers[i]);
hasGroup = true;
}
//bool hasGroup = false;
//for (int g = 0; g < Groups.Count; g++)
//{
//if (groupLogic(Groups[g].Center, _allSingleMembers[i]))
//{
// Groups[g].Add(_allSingleMembers[i]);
// hasGroup = true;
// break;
//}
//}
if (!hasGroup)
{
MakeNewGroup(_allSingleMembers[i]);
}
}
}
}
public void TestBoundingBox()
{
List <Point> points = new List <Point>();
points.Add(new Point(1, 9));
points.Add(new Point(2, 2));
points.Add(new Point(2, 5));
points.Add(new Point(2, 10));
points.Add(new Point(2, 12));
points.Add(new Point(3, 7));
points.Add(new Point(4, 11));
points.Add(new Point(5, 8));
points.Add(new Point(6, 7));
points.Add(new Point(7, 3));
points.Add(new Point(7, 4));
points.Add(new Point(7, 5));
points.Add(new Point(7, 11));
points.Add(new Point(8, 3));
points.Add(new Point(8, 4));
points.Add(new Point(8, 5));
points.Add(new Point(9, 3));
points.Add(new Point(9, 4));
points.Add(new Point(9, 5));
points.Add(new Point(9, 10));
points.Add(new Point(9, 11));
points.Add(new Point(10, 3));
points.Add(new Point(10, 10));
points.Add(new Point(10, 11));
points.Add(new Point(11, 6));
Func <Point, Point, int> xWise = (p1, p2) => p1.X.CompareTo(p2.X);
Func <Point, Point, int> yWise = (p1, p2) => p1.Y.CompareTo(p2.Y);
Func <Point, Point, int>[] funcs = { xWise, yWise };
var kdtree = new BalancedKdTree <Point>(points.ToArray(), funcs.ToList(), Point.NaN, i => i);
Assert.AreEqual(true, CheckBoundingBox(kdtree.Root));
}
