K-Medoids Clustering
K-Medoids is like K-Means but takes actual data points as centers (medoids), supporting clustering with arbitrary distance metrics.
Purpose
To provide clustering that is more robust to noise and outliers and supports arbitrary distances.
Mechanism
The center (medoid) is the actual data point in the cluster that minimizes total distance. The PAM algorithm swaps a medoid with a non-medoid whenever doing so reduces total distance. It is more robust than K-Means but costlier at O(n^2).
Use cases
- Robust clustering
- Non-Euclidean distance clustering
- Bioinformatics