From: Stéphanie D'agata <dagatastephanie_at_gmail.com>

Date: Mon, 21 Jun 2010 14:46:01 +0200

Date: Mon, 21 Jun 2010 14:46:01 +0200

I now need to get a confidence interval for my predicted count and I want to compute the coefficient of variation.

My questions are the following:

About the coefficient of variation, is it equal to the standard deviation/ mean for all the distributions???

Can I say that for a poisson distribution, it is therefore equal to 1/sqrt(mean) and for a negative binomial distribution, variance = mean + mean^2/theta (theta the canonical parameter given in glm.nb summary). I can then calculate my St. Dev and then CV?

I really appreciate your help.

Regards,

-- Stéphanie D'agata [[alternative HTML version deleted]]Received on Mon 21 Jun 2010 - 12:51:29 GMT______________________________________________ R-help_at_r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.

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