KD tree data structure for searching N-dimensional vectors.

The KD tree data structure can be used for all kinds of searches that involve N-dimensional vectors, e.g. neighbor searches (find all points within a radius of a given point) or finding all point pairs in a set that are within a certain radius of each other. See “Computational Geometry: Algorithms and Applications” (Mark de Berg, Marc van Kreveld, Mark Overmars, Otfried Schwarzkopf). Author: Thomas Hamelryck.