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
    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
    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
    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
    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
    Nov 25, 2013 at 19:32


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