Kmeans Clustering CCC problem

Question

JMP Kmeans clustering is not calculating a CCC statistic for a subset of my data. I have a data file with a little over 4000 unique sites. Using this data set I have successfully used kmeans clustering and JMP displays a CCC statistic. I created a subset of this data using a variable and now have two new data tables (one with around 200 rows and the other with 4000+). Whenever I go through the same kmeans clustering process on the larger subset of the data JMP will not spit out a CCC statistic. Any ideas about what is going on here?

jessez · Accepted Answer

After a couple hours (and you will see they were wasted hours...) of trying to figure this out I caught the problem. One of the variables I used in the clustering process was zero for most of the data set. It turns out that it was zero for all of the rows in the subset I was interested in using Kmeans clustering. The zero values blow up the CCC. Problem solved.