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: [EMAIL PROTECTED] web: http://www.synequanon.com Number of attachments included with this message: 0 This message (and any associated files) is confidential and\...{{dropped}} ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help