Hotspots Detection in Spatial Analysis via the Extended Gustafson-Kessel Algorithm

Table 1

Results of the EGK applied to the event’s subsets.

Year	Initial number of clusters	Final number of clusters	|𝑈^(𝑙)−𝑈^(𝑙−1)|	𝜀
2004–2006	15	7	0.79×10^−2	1×10^−2
2007	15	7	0.65×10^−2	1×10^−2
2008	15	7	0.68×10^−2	1×10^−2
2009	15	8	0.74×10^−2	1×10^−2
2010	15	8	0.81×10^−2	1×10^−2