“…Beside traditional PCs produced mostly by 3D scanners [9], a set of points can also represent general spatial information [10] such as location, GPS coordinates on the map [11], swarm particles [12], nodes of graph generated by visualization algorithms [13], etc. We focus on 2D point clouds as they are highly investigated in the areas such as data mining [2,3,10], computer graphics [14,15], image analysis [16][17][18], geographic information systems (GISs) [19][20][21][22][23], sensor networks [24,25], triangulation [26][27][28][29] and data visualization [12]. In the mentioned application fields, the point indexing/clustering algorithms are crucial, e.g., for efficient organization of data in the memory, analyzing their properties, visualization of clusters, computation of forces in particle systems and searching near neighbors.…”