I'm wondering how to calculate the C-Index for determining a 'good' number of groups in a cluster analysis in Stata? It's mentioned in this post (What is an acceptable value of the Calinski & Harabasz (CH) criterion?) for R, but it seems Stata does not provide a built-in solution.

Thank you!

  • $\begingroup$ What makes it difficult for you to calculate it as soon as you understood it? Or you haven't undersood it yet? $\endgroup$
    – ttnphns
    Commented Nov 25, 2013 at 16:33
  • $\begingroup$ P.s. My macro for SPSS computes it. But you said you want code for Stata... $\endgroup$
    – ttnphns
    Commented Nov 25, 2013 at 16:35
  • $\begingroup$ Where can I find your macro? It seems it can be implemented in Stata using the cluster programming subroutines, but I have no experience in programming those kind of things. $\endgroup$
    – yumba
    Commented Nov 25, 2013 at 16:45
  • $\begingroup$ OK then, if you have SPSS, try it. Visit my web-page and download "Clustering criterions". The documentation is only partly in english, so, if you get questions ask me by email. Please note: 1) C-Index takes time to compute (I don't recommend the macro if you have, say, 500+ objects) but point-biserial r is fast and often give similar results; 2) C-Index is just one of many clustering indices, and you might want to choose another (e.g. Silhouette is quite popular nowadays). $\endgroup$
    – ttnphns
    Commented Nov 25, 2013 at 16:58
  • $\begingroup$ My instinct is that this would require delving much deeper into Stata's code than is easy or even possible. A more fundamental concern is that the criterion is of dubious relevance unless it was used to define clusters in the first place or can be related directly to cluster generation. $\endgroup$
    – Nick Cox
    Commented Nov 25, 2013 at 19:32


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.