/// <summary>
/// Creates a new 2-dimensional k-d tree.
/// </summary>
/// <param name="points"></param>
/// <param name="distance_delegate"></param>
public Tree2D(IEnumerable <PointType> points,
Distance distance_delegate)
{
// set the distance delegate.
_distance_delegate = distance_delegate;
// create the list.
List <PointType>[] sorted_points = new List <PointType> [2];
// sort points per dimension.
for (int dim = 0; dim < 2; dim++)
{
// create the points list.
List <PointType> points_list = new List <PointType>(points);
// sort the list.
points_list.Sort(new Comparison <PointType>(delegate(PointType p1, PointType p2)
{
return(p1[dim].CompareTo(p2[dim]));
}));
// add the list to the array.
sorted_points[dim] = points_list;
}
// construct the root.
_root = new Tree2DNode <PointType>(_distance_delegate, sorted_points, 0);
}
/// <summary>
/// Adds a point to the tree.
/// </summary>
/// <param name="value"></param>
public void Add(PointType value)
{
double value_dimension = value[_dimension];
if (value_dimension < _value[_dimension])
{ // add to the lesser side.
if (_lesser == null)
{
_lesser = new Tree2DNode <PointType>(_distance_delegate, value, _dimension + 1 % 2);
}
else
{
_lesser.Add(value);
}
}
else
{ // add to the bigger side.
if (_bigger == null)
{
_bigger = new Tree2DNode <PointType>(_distance_delegate, value, _dimension + 1 % 2);
}
else
{
_bigger.Add(value);
}
}
}
/// <summary>
/// Creates a 2D tree in a balanced way.
/// </summary>
/// <param name="distance_delegate"></param>
/// <param name="sorted_points"></param>
/// <param name="dimension"></param>
public Tree2DNode(Tree2D <PointType> .Distance distance_delegate, List <PointType>[] sorted_points, int dimension)
{
// set the distance delegate.
_distance_delegate = distance_delegate;
// set the dimension.
_dimension = dimension;
// get the sorted list in question.
List <PointType> points = sorted_points[_dimension];
// get the middle point.
int middle = points.Count / 2;
// create this point.
_value = points[middle];
// split the list.
List <PointType>[] lesser_points = new List <PointType> [2];
List <PointType>[] bigger_points = new List <PointType> [2];
lesser_points[_dimension] = new List <PointType>(points.GetRange(
0, middle - 1));
bigger_points[_dimension] = new List <PointType>(points.GetRange(
middle + 1, points.Count - (middle + 1)));
// calculate the other dimension.
int other_dimension =
(_dimension + 1) % 2;
// remove the points from the other dimension lists.
lesser_points[other_dimension] = new List <PointType>(
sorted_points[other_dimension].Except <PointType>(bigger_points[_dimension]));
lesser_points[other_dimension].Remove(_value);
bigger_points[other_dimension] = new List <PointType>(
sorted_points[other_dimension].Except <PointType>(lesser_points[_dimension]));
bigger_points[other_dimension].Remove(_value);
// create the other nodes.
if (lesser_points[other_dimension].Count == 1)
{
_lesser = new Tree2DNode <PointType>(_distance_delegate,
lesser_points[other_dimension][0], other_dimension);
}
else if (lesser_points[other_dimension].Count > 1)
{
_lesser = new Tree2DNode <PointType>(_distance_delegate,
lesser_points, other_dimension);
}
if (bigger_points[other_dimension].Count == 1)
{
_bigger = new Tree2DNode <PointType>(_distance_delegate,
bigger_points[other_dimension][0], other_dimension);
}
else if (bigger_points[other_dimension].Count > 1)
{
_bigger = new Tree2DNode <PointType>(_distance_delegate,
bigger_points, other_dimension);
}
}
public Tree2D(IEnumerable <PointType> points, Tree2D <PointType> .Distance distance_delegate)
{
this._distance_delegate = distance_delegate;
List <PointType>[] sorted_points = new List <PointType> [2];
int num;
for (int dim = 0; dim < 2; dim = num + 1)
{
List <PointType> pointTypeList = new List <PointType>(points);
pointTypeList.Sort((Comparison <PointType>)((p1, p2) => p1[dim].CompareTo(p2[dim])));
sorted_points[dim] = pointTypeList;
num = dim;
}
this._root = new Tree2DNode <PointType>(this._distance_delegate, sorted_points, 0);
}
public void Add(PointType value)
{
if (value[this._dimension] < this._value[this._dimension])
{
if (this._lesser == null)
{
this._lesser = new Tree2DNode <PointType>(this._distance_delegate, value, this._dimension + 1);
}
else
{
this._lesser.Add(value);
}
}
else if (this._bigger == null)
{
this._bigger = new Tree2DNode <PointType>(this._distance_delegate, value, this._dimension + 1);
}
else
{
this._bigger.Add(value);
}
}
public Tree2DNode(Tree2D <PointType> .Distance distance_delegate, List <PointType>[] sorted_points, int dimension)
{
this._distance_delegate = distance_delegate;
this._dimension = dimension;
List <PointType> sortedPoint = sorted_points[this._dimension];
int index = sortedPoint.Count / 2;
this._value = sortedPoint[index];
List <PointType>[] sorted_points1 = new List <PointType> [2];
List <PointType>[] sorted_points2 = new List <PointType> [2];
sorted_points1[this._dimension] = new List <PointType>((IEnumerable <PointType>)sortedPoint.GetRange(0, index - 1));
sorted_points2[this._dimension] = new List <PointType>((IEnumerable <PointType>)sortedPoint.GetRange(index + 1, sortedPoint.Count - (index + 1)));
int dimension1 = (this._dimension + 1) % 2;
sorted_points1[dimension1] = new List <PointType>(sorted_points[dimension1].Except <PointType>((IEnumerable <PointType>)sorted_points2[this._dimension]));
sorted_points1[dimension1].Remove(this._value);
sorted_points2[dimension1] = new List <PointType>(sorted_points[dimension1].Except <PointType>((IEnumerable <PointType>)sorted_points1[this._dimension]));
sorted_points2[dimension1].Remove(this._value);
if (sorted_points1[dimension1].Count == 1)
{
this._lesser = new Tree2DNode <PointType>(this._distance_delegate, sorted_points1[dimension1][0], dimension1);
}
else if (sorted_points1[dimension1].Count > 1)
{
this._lesser = new Tree2DNode <PointType>(this._distance_delegate, sorted_points1, dimension1);
}
if (sorted_points2[dimension1].Count == 1)
{
this._bigger = new Tree2DNode <PointType>(this._distance_delegate, sorted_points2[dimension1][0], dimension1);
}
else
{
if (sorted_points2[dimension1].Count <= 1)
{
return;
}
this._bigger = new Tree2DNode <PointType>(this._distance_delegate, sorted_points2, dimension1);
}
}
