I am using code from Using BIC to estimate the number of k in KMEANS (answer by Prabhath Nanisetty) to find BIC values for K-means using different number of components. However, using iris dataset, I get following results:
N_clusters BIC 1 -863.896405 2 -674.133038 3 -616.557809 4 -603.357368 5 -582.428798 6 -596.073710 7 -590.086212 8 -579.876476 9 -554.665433
This is shown in following plot:
The plot after standardization of data:
Is is normal to have negative values for BIC. Which is the best number of clusters by BIC here, especially considering that iris data set has 3 groups? Most negative value in above list is for 1 cluster only.