k-means, step by step
Nobody labeled these points. k-means looks for k groups by alternating two simple steps.
The centers start at randomly chosen data points. Next: assign every point to its nearest center.
Center moves0
Inertia (spread within clusters)n/a
Try this
- Step through Three blobs one half-step at a time and watch the inertia chart only ever go down.
- Press New starting centers a few times with random starts until two centers share one blob.
- Try Stretched and No groups to see k-means find groups that are not really there.