SSE and Silhouette Value for Evaluate K-means

Hi, I wrote a program that uses k-means for clustering data, my data is 2D and in range(-2, 2). I want to know how SSE and Silhouette Value works to find optimum "k"?? Besides I want to write a code and don't want to use built-in functions. Thanks

Answer 1

[Ting Su]

The silhouette value can be used to estimate the number of clusters. Function “evalclusters†also provides a few other criteria to estimate the optimal number of clusters. SSE is the measure that K-means tries to minimize when the number of clusters is given. It can’t be used to estimate the number of clusters because SSE values are monotonically non-decreasing as the numbers of clusters increases.