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Re: st: zero-inflated analyses: when do you decide that is zero-inflated?
From
David Hoaglin <[email protected]>
To
[email protected]
Subject
Re: st: zero-inflated analyses: when do you decide that is zero-inflated?
Date
Wed, 17 Jul 2013 06:49:52 -0400
Cris,
A GLM with a log link is what I had in mind. I would explore first,
by using -regress- on the nonzero sizes, untransformed and in some
transformed scales, and making the customary plots of residuals. The
log is often a good transformation to try. Since size is a linear
measure, I would also try (size)^2, because area has a meaningful
interpretation.
David Hoaglin
On Wed, Jul 17, 2013 at 3:39 AM, Cris Dogaru (Oregon State University)
<[email protected]> wrote:
> Thanks a lot David.
> It's a good idea to use a transformed scale for the regression part. I
> could probably use the link(log) in a glm model?..
> There's the tpm user-written command
> tpm outcome predictors, firstpart(logit) secondpart(glm,
> family(gaussian) link(log))
>
> Cris
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