[R] Antwort: Re: an alternative to R for nonlinear stat models

[benedikt.gehr at ieu.uzh.ch]

   Hi Paul

   Oh ok sorry, I send you below a copy of the R code I was using. It's very
   possible that my programming is slow as well. I'm very happy to learn.

   Sorry the code is a bit long, but its structured like this and cotains three
   main functions and the optimization:



   1. Input - (I didn't send the data)

   2.  Function  to  calculate the cell probabilities for the multinomial
   likelihood

   3. Function to calculate the multinomial

   4.Function to be optimized

   5. then I set the starting values

   6. optimization using mle2



   hope that helps



   cheers



   Beni

   -----Paul Hiemstra <p.hiemstra at geo.uu.nl> schrieb: -----

     An: benedikt.gehr at ieu.uzh.ch
     Von: Paul Hiemstra <p.hiemstra at geo.uu.nl>
     Datum: 16.06.2010 09:36
     Kopie: r-help at r-project.org, davef at otter-rsch.com
     Betreff: Re: [R] an alternative to R for nonlinear stat models
     On 06/16/2010 07:35 AM, benedikt.gehr at ieu.uzh.ch wrote:
     >     Hi
     >     I implemented the age-structure model in Gove et al (2002) in R,
     which is a
     >     nonlinear statistical model. However running the model in R was very
     slow.
     >     So Dave Fournier suggested to use the AD Model Builder Software
     package and
     >     helped me implement the model there.
     >     ADMB was incredibly fast in running the model:
     >     While running the model in R took 5-10 minutes, depending on the
     settings,
     >     in ADMB it took 1-2 seconds!
     >     I'm reporting this so that people who have performance issues with
     nonlinear
     >       statistical models in R will know that there is a good free
     alternative for
     >     more difficult problems.
     >     There  is also a help platfrom equivalent to the one for R, and
     people
     >     running it are extremley helpful.
     >     I hope this might help someone
     >     cheers
     >     Beni
     > ______________________________________________
     > R-help at r-project.org mailing list
     > [1]https://stat.ethz.ch/mailman/listinfo/r-help
     > PLEASE do read the posting guide
     [2]http://www.R-project.org/posting-guide.html
     > and provide commented, minimal, self-contained, reproducible code.
     >
     Hi Beni,
     Thanks for posting information that might be useful for people on the
     list. The only thing is that without a little more detail on how exactly
     you implemented things in R, we are left to guess if the performance
     issues are a problem of R, or that your particular implementation was
     the problem. There are was of implementing R code in two ways, where the
     first takes minutes and the second 1-2 seconds. Furthermore, you are
     giving us no option to defend R ;).
     cheers,
     Paul
     --
     Drs. Paul Hiemstra
     Department of Physical Geography
     Faculty of Geosciences
     University of Utrecht
     Heidelberglaan 2
     P.O. Box 80.115
     3508 TC Utrecht
     Phone:  +3130 274 3113 Mon-Tue
     Phone:  +3130 253 5773 Wed-Fri
     [3]http://intamap.geo.uu.nl/~paul
     [4]http://nl.linkedin.com/pub/paul-hiemstra/20/30b/770

References

   1. https://stat.ethz.ch/mailman/listinfo/r-help
   2. http://www.r-project.org/posting-guide.html
   3. http://intamap.geo.uu.nl/~paul
   4. http://nl.linkedin.com/pub/paul-hiemstra/20/30b/770