“…In these figures, the samples of two clusters provided by the clustering methods are presented by black triangle symbol "▽", and blue pentagram symbol " ". As mentioned above, the algorithms used in the competitions are K-means, FCM, KFCM Chen, 2003a, 2003b), NJW (Ng et al, 2002), GKFCM (Gustafson and Kessel, 1979), PFCM (Pal et al, 2005), KPCA (Scholkopf et al, 1999), GSOM (Ilc and Dobnikar, 2012), SGC (Teng and Jin, 2006) and the proposed gravity clustering.…”