[R-sig-ME] question on nbinom1
Don Cohen
don-|me4 @end|ng |rom |@|@@c@3-|nc@com
Tue Oct 13 21:01:33 CEST 2020
Thank you.
This is perfectly clear and enables further analysis.
I hope you can arrange to put it in some (even better, much) documentation.
I wish it were in wikipedia.
Ben Bolker writes:
>
> I believe the R d/p/q/r functions corresponding to glmmTMB's
> implementation of *nbinom1 would look like this:
>
>
> rnbinom1 <- function(n, mu, phi) {
> ## var = mu*(1+phi) = mu*(1+mu/k) -> k = mu/phi
> rnbinom(n, mu=mu, size=mu/phi)
> }
>
> dnbinom1 <- function(x, mu, phi, ...) {
> dnbinom(n, mu=mu, size=mu/phi, ...)
> }
>
> pnbinom1 <- function(q, mu, phi, ...) {
> pnbinom(q, mu=mu, size=mu/phi, ...)
> }
>
> qnbinom1 <- function(p, mu, phi, log=FALSE) {
> pnbinom(p, mu=mu, size=mu/phi, ...)
> }
>
>
> (there would be an even more clever/inscrutable way to do this by
> transforming the body of the code, without repeating oneself so much,
> but it would probably be a bad idea)
>
> On 10/12/20 6:34 AM, Mollie Brooks wrote:
> > I think the easiest way to get a numerical representation of the distribution from a fitted model would be using the simulate function.
> >
> > There's an example of how to do that on pages 392-393 of this pdf (including Figs 6 and 7)
> > https://journal.r-project.org/archive/2017/RJ-2017-066/RJ-2017-066.pdf <https://journal.r-project.org/archive/2017/RJ-2017-066/RJ-2017-066.pdf>
> >
> > cheers,
> > Mollie
> >
> >> On 10Oct 2020, at 14:23, Don Cohen <don-lme4 using isis.cs3-inc.com> wrote:
> >>
> >> Mollie Brooks writes:
> >>
> >>> I don't have a copy of Hardin & Hilbe 2007 on hand, but I answered
> >>> a few of your questions below.
> >>
> >> Thank you.
> >>
> >> One more question:
> >>
> >> How can I compute the nbinom1 distribution?
> >> Is there a formula for the pdf or cdf ? An R function ?
> >>
> >
> >
> > [[alternative HTML version deleted]]
> >
> > _______________________________________________
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> > https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
> >
>
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