Can k-means clustering do classification?

Question

I want to know whether the k-means clustering algorithm can do classification?

If I have done a simple k-means clustering .

Assume I have many data , I use k

Answer 1

Yes, we can do classification.

I wouldn't say the algorithm itself (like #1) is particularly well-suited to classifying points, as incorporating data to be classified into your training data tends to be frowned upon (unless you have a real-time system, but I think elaborating on this would get a bit far from the point).

To classify a new point, simply calculate the Euclidean distance to each cluster centroid to determine the closest one, then classify it under that cluster.

There are data structures that allows you to more efficiently determine the closest centroid (like a kd-tree), but the above is the basic idea.