/// <summary>
/// Returns the nearest neighbours for the given point.
/// </summary>
/// <param name="point"></param>
/// <returns></returns>
public PointType SearchNearestNeighbour(PointType point)
{
return(_root.SearchNearestNeighbour(point, null));
}
/// <summary>
/// Returns the nearest neighbours for the given point.
/// </summary>
/// <param name="point"></param>
/// <param name="exceptions"></param>
/// <returns></returns>
public PointType SearchNearestNeighbour(PointType point, ICollection <PointType> exceptions)
{
// keeps the result.
PointType result = default(PointType);
// decide where to get the result from.
double value_dimension = point[_dimension];
bool lesser = true;
if (value_dimension < _value[_dimension])
{ // get from the lesser side.
if (_lesser == null)
{
if (exceptions == null ||
!exceptions.Contains(_value))
{
result = _value;
}
}
else
{
result = _lesser.SearchNearestNeighbour(point, exceptions);
}
}
else
{ // get from the bigger side.
lesser = false;
if (_bigger == null)
{
if (exceptions == null ||
!exceptions.Contains(_value))
{
result = _value;
}
}
else
{
result = _bigger.SearchNearestNeighbour(point, exceptions);
}
}
// do we need to search the other side.
double distance = double.MaxValue;
if (result != null)
{
_distance_delegate.Invoke(result, point);
}
// check if the current point is closer.
double distance_this = _distance_delegate.Invoke(_value, point);
if (distance > distance_this)
{
result = _value;
distance = distance_this;
}
// test if the other side needs to be tested.
double distance_to_other_side = 0;
if (result != null)
{
System.Math.Abs(result[_dimension] - _value[_dimension]);
}
if (distance > distance_to_other_side)
{
PointType other_result = default(PointType);
if (lesser)
{
if (_bigger != null)
{
other_result = _bigger.SearchNearestNeighbour(point, exceptions);
}
}
else
{
if (_lesser != null)
{
other_result = _lesser.SearchNearestNeighbour(point, exceptions);
}
}
if (other_result != null)
{
double distance_other = _distance_delegate.Invoke(other_result, point);
if (distance_other < distance)
{
result = other_result;
}
}
}
return(result);
}
