There has recently been some discussion on the list about
AD Model builder and the suitability of R for constructing the
types of models used in fisheries management.
https://stat.ethz.ch/pipermail/r-help/2006-January/086841.html
https://stat.ethz.ch/pipermail/r-help/2006-January/086858.ht
dave fournier <[EMAIL PROTECTED]> wrote:
> I think that many R users understimate the numerical challenges
> that some of the typical nonlinear statistical model used in different
> fields present. R may not be a suitable platform for development for
> such models.
>
> Around 10 years ago John S
Did you try supplying gradient information to nlminb? (I note that
nlminb is used for the optimization, but I don't see any gradient
information supplied to it.) I would suspect that supplying gradient
information would greatly speed up the computation (as you note in
comments at http://otter-
Dave
> Did you try supplying gradient information to nlminb? (I note that
nlminb is used for the optimization, but I don't see any gradient
information supplied to it.) I would suspect that supplying gradient
information would greatly speed up the computation (as you note in
comments
Hi, Mike & Dave:
Have you considered nonlinear mixed effects models for the types
of problems considered in the comparison paper you cite? Those
"benchmark trials" consider "T years of data ... for A age classes and
the total number of parameters is m = T+A+5". Without knowing more
ab
On 11/24/06, dave fournier <[EMAIL PROTECTED]> wrote:
>
>
>Dave
> > Did you try supplying gradient information to nlminb? (I note that
> nlminb is used for the optimization, but I don't see any gradient
> information supplied to it.) I would suspect that supplying gradient
> information w
Spencer,
I tried the mixed effects approach you suggest using the random effects
module of
AD Model Builder: (http://www.otter-rsch.ca/admbre/admbre.html). What are
94 unbounded parameters in Schnute et al (1998), now become realizations
of a Gaussian random variable, with the corresponding standa
Douglas Bates wrote:
>
snip
>
> Don't you find it somewhat disingenuous that you publish a comparison
> between the AD Model Builder software that you sell and R - a
> comparison that shows a tremendous advantage for your software - and
> then you write "I am not proficient in R"?
>
I think t
