Message-ID: <Pine.LNX.4.64.1206221125560.30121@orpheus.qimr.edu.au>
Date: 2012-06-22T02:13:35Z
From: David Duffy
Subject: Do glmer and glmmadmb calculate log likelihood on thesame scale ?
In-Reply-To: <CANz9Z_+DieCW7Lz=2gMVLW2Fy17jW8LvoBYhoEmchKfJmG8FnA@mail.gmail.com>
On Thu, 21 Jun 2012, Joshua Wiley wrote:
> Just a note that those are not the same models.
Huh.
> OR you could change glmmadmb() to
>
> fm2 <- glmmadmb(y~Base*trt+Age+Visit+(Visit|subject),
> data=epil2, family="poisson", corStruct = "full")
> however, on my machine, there are warnings about the matrix not being
> positive definite, and the model never converges.
I haven't updated glmmADMB recently (0.6.4 2011-08-30), so it
gives the warning, but continues merrily to give:
(Intercept) Visit
(Intercept) 0.24931 0.24931
Visit 0.54572 0.54572
and the same likelihood as before
Log-likelihood: -655.41
glmer was
Groups Name Variance Std.Dev. Corr
subject (Intercept) 0.24912 0.49912
Visit 0.53962 0.73459 0.011
'log Lik.' -262.6586 (df=9)
Your suggestion Visit + (1 | Visit) + (0 + Visit | subject)
gave me
Groups Name Variance Std.Dev.
subject Visit 0.77301 0.87921
Visit (Intercept) 5.1845e-16 2.2769e-08
'log Lik.' -421.1128 (df=8)
I have to admit, the direction of the change in loglikelihood here
confuses me a little ;)
My lme4 is also a little antiquated: 0.999375-42 (2011-10-02).
--
| David Duffy (MBBS PhD) ,-_|\
| email: davidD at qimr.edu.au ph: INT+61+7+3362-0217 fax: -0101 / *
| Epidemiology Unit, Queensland Institute of Medical Research \_,-._/
| 300 Herston Rd, Brisbane, Queensland 4029, Australia GPG 4D0B994A v