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RE: st: RE: loglink and normality, mixed model
From
"Feiveson, Alan H. (JSC-SK311)" <[email protected]>
To
"[email protected]" <[email protected]>
Subject
RE: st: RE: loglink and normality, mixed model
Date
Tue, 25 Feb 2014 14:17:01 +0000
Hi Ruud - I experimented with some simulated clustered normally distributed data (y) with positive subject-specific means, but large enough error term so that some values of y were negative. -meglm- worked fine. In my simulation, I purposely generated all the subject-specific means to be positive. I think the problem may be that with a log link, all the subject-specific means must be positive, so that if the estimated variance of the random intercept is too large at any stage of the estimation, some subject-specific means would become negative, thus conflicting with the model.
Al
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Ruud van Lieshout
Sent: Tuesday, February 25, 2014 4:08 AM
To: [email protected]
Subject: RE: st: RE: loglink and normality, mixed model
hi Al,
well in theory you are right, but my question also holds for negative values ..The model can generate negative values (eps ~N(0, sigma^2)) but meglm can't handles those !! Why not?
regards,
Ruud
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