Message-ID: <Pine.A41.4.44.0208221527170.93374-100000@homer16.u.washington.edu>
Date: 2002-08-22T22:29:38Z
From: Thomas Lumley
Subject: Calculating dispersion in glm
In-Reply-To: <F130hm9R30xyhgvpx9P0000cc4f@hotmail.com>
On Fri, 23 Aug 2002, David Mackie wrote:
> Hi all,
>
> How is dispersion calculated within the glm function in R ?
>
It isn't.
It's calculated within the summary.glm function (or supplied by the user).
as
sum(object$weights * object$residuals^2)/df.r
which works out to be equal to the mean square of the Pearson residuals.
-thomas
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