Prediction accuracy cannot be computed in a purely unsupervised setting: you don't have labels for the samples. You can compare the cluster found by k-means ru

Prediction accuracy cannot be computed in a purely unsupervised setting: you don't have labels for the samples. You can compare the cluster found by k-means run several times against what you get with a randomized version of your dataset though: http://blog.echen.me/2011/03/19/counting-clusters/ http://blog.echen.me/2011/03/19/counting-clusters/