[R-sig-ME] Question on glmmTMB

[Ebhodaghe Faith]

Thank you, Ben Bolker.

I find your response very helpful.

Regards,
Faith

On Sat, 19 Jun 2021, 1:13 a.m. Ben Bolker, <bbolker using gmail.com> wrote:

>    This should be fine. Unlike many mixed model packages, glmmTMB can
> handle models with no random effect.  When in doubt, you can just try
> out a comparison - this obviously isn't a 100% guarantee that something
> works reliably, but in this example all three approaches give very
> similar answers:
>
> library(glmmTMB)
> library(bbmle)
> m1 <- glmmTMB(count~spp + mined, Salamanders, family=nbinom2)
> m2 <- MASS::glm.nb(count~spp + mined, Salamanders)
> m3 <- mle2(count ~ dnbinom(mu = exp(logmu), size = exp(logk)),
>             parameters = list(logmu ~ spp + mined),
>             start = list(logmu = 0, logk = 0),
>             data = Salamanders)
>
> library(broom)
> library(broom.mixed)
> tidy(m1)
> tidy(m2)
> tidy(m3)
>
> On 6/18/21 4:10 AM, Ebhodaghe Faith wrote:
> > Dear All,
> >
> > The glmmTMB package is used to model data with mixed effects. For
> example:
> >
> > glmmTMB(count~spp + mined + (1|site), Salamanders, family=nbinom2)
> >
> > But I'm just curious to know what happens when the package is used to
> model
> > data without random effects (will this still be fine? How does this
> compare
> > with just using the glm function in the MASS package?). See example
> below:
> >
> > glmmTMB(count~spp + mined, Salamanders, family=nbinom2)
> >
> > With kind regards,
> > Faith
> >
> >       [[alternative HTML version deleted]]
> >
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> >
>
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