kmeans_silhouette

Finds the optimal number of clusters (k) for a given dataset using the Silhuette method.

The function takes in a dataset in the format of [Nx2] where each data-point is represented as [xi,yi] and the maximum number of clusters to consider (kmax). The function then uses kmeans and Silhouette coefficients to determine the optimal number of clusters. The function outputs S-score for each k and the optimal k.

Refer to the following link for details about the Silhouette clustering algorithm:
https://en.wikipedia.org/wiki/Silhouette_(clustering)