[R] relationship between two discrete variables

[Simon Fear]

Don't use correlation for discrete variables; the 
correlation coefficient does not vary freely between -1 
and 1, it is tightly constrained by the joint probabilities of 
nonzero outcomes in a rather counterintuitive way.  
Please ask me off list if you don't follow this.

While I'm off-topic, following Tom B's comment, the only
way I know to break lines in emails using Explorer is to
actually type returns - is what I always do here and is a
pain in  the ****. If anyone knows how to overcome this
I'd be very grateful. [I don't have a choice about using
Explorer]  
 
Simon Fear 
Senior Statistician 
Syne qua non Ltd 
Tel: +44 (0) 1379 644449 
Fax: +44 (0) 1379 644445 
email: Simon.Fear at synequanon.com 
web: http://www.synequanon.com 
  
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