How can I decide the best number of clusters within 'Proc Fastclus'?

[Crubal]

Hi, I have a question when working on cluster analysis.

How can I draw an Elbow Evaluation plot in determining the best number of clusters? Thanks!

proc fastclus
data=HOTEL_EMEA 
maxc=10
maxiter=10
out=clust;
var avg_pct;
run;

[Ksharp]

I would do Primary Component Analysis and get those two PC and polt them by proc sgplot ,and you could probably get N of clusters. 

[Babloo]

Ksharp,

Could you please give me one simple example? What do you mean by 'get those two PC' in your reply?

[Ksharp · Accepted solution]

use proc princomp to get two primary component of your data. And plot them at X-Y axis .you can see the number of cluster you should split.

Here is an example:

http://blogs.sas.com/content/iml/2014/11/07/distribution-of-blood-types.html

[Crubal]

Cool!

[Babloo]

Can we cluster analysis only with continous varaibles?