“…In particular spatial clustering algorithms, which group similar spatial objects into classes, can be used for knowledge discovery in spatial databases, i.e., databases managing 2D or 3D points, polygons, etc., or points in some d-dimensional feature space (see, e.g., Fayyad et al, 1996;Han et al, 2001;Koperski et al, 1998;Steinbach et al, 2003;Xu and Wunsch, 2005). …”