How may I calculate Accuracy in NLTK KMeans Clustering
Precision, Recall, and thus the F-measure are inappropriate for cluster analysis. Clustering is not classification, and clusters are not classes!
Common measures for clustering (if you are trying to compare with existing labels, which does not make a whole lot of sense - if you already know the classes, then use classification and not clustering) are the Adjusted Rand Index and its variants.
I am trying to use NLTK's KMeans Clustering Algorithm. 
It is generally going fine. 
I want to use the Metrics package of NLTK to determine precision,recall and f measure.
I searched for some examples in web and in other references but may be without a clue. 
If any one may kindly cite an example or reference. 
Thanks in Advance.