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

You are confusing the concepts of clustering and classification. When you have labeled data, you already know how the data is clustered according to the labels and there is no point in clustering the data unless if you want to find out how well your features can discriminate the classes.

If you run the k-means algorithm to find the centroid of each class and then use the distances from the centroids to classify a new data point, you in fact implement a form of the linear discriminant analysis algorithm assuming the same multiple-of-identity covariance matrix for all classes.