Significance of degrees of freedom in nlme

classic Classic list List threaded Threaded
2 messages Options
Reply | Threaded
Open this post in threaded view
|

Significance of degrees of freedom in nlme

gabriela escati peñaloza
Dear Dr. Bates,
Thank you very much for your response. I had consulted
the algorithm described in Pinheiro and Bates.
However, what I don't understand (among other things)
is why my two parameters appear to be estimated at
different grouping levels (based on the DF values).
Affect this different values of DF at the estimates
parameters? The estimates fixed effects were get at
the same level of grouping?
I apreciate any response.




Lic. Gabriela Escati Peñaloza
Biología y Manejo de Recursos Acuáticos
Centro Nacional Patagónico(CENPAT).
CONICET
Bvd. Brown s/nº.
(U9120ACV)Pto. Madryn
Chubut
Argentina

Tel: 54-2965/451301/451024/451375/45401 (Int:277)
Fax: 54-29657451543


       


       
               
___________________________________________________________
1GB gratis, Antivirus y Antispam
Correo Yahoo!, el mejor correo web del mundo
http://correo.yahoo.com.ar

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Reply | Threaded
Open this post in threaded view
|

Re: Significance of degrees of freedom in nlme

Spencer Graves
          Your question begins, "Dear Dr. Bates", yet Bates does not appear as
an addressee in the copy of your question that I recieved via r-help.  I
will offer a couple of suggestions in the hopes that they might help
you.  Since your question did not include enough detail for anyone to
answer without additional information, I used 'RSiteSearch("gabriela
escati peñaloza")' to find earlier posts that might be related.  This
generated 14 hits, the most relevant of which seemed to be
"http://finzi.psych.upenn.edu/R/Rhelp02a/archive/69466.html".  From
this, I copy the following:  

formula(my data.gd)
dLt ~ Lt | ID
TasavB<- function(Lt, Linf, K) (K*(Linf-Lt))
my model.nlme <- nlme (dLt ~ TasavB(Lt, Linf, K),
data = my data.gd,
fixed = list(Linf ~ 1, K ~ 1),
start = list(fixed = c(70, 0.4)),
na.action= na.include, naPattern = ~!is.na(dLt))

          I assume something got garbled here, because constructs like "my
data.gd" generate a 'syntax error' for me;  I therefore assume it is
"my_data.gd" (with an underscore between "my" and "data.gd".)  Try the
following:

sapply(my_data.gd, class)

          What columns of my_data.gd are factors, and how do they relate to
Linf and K?  You can explore this using "table".

          If you would like more help from this listserve, please submit
another post.  Before you do, however, PLEASE do read the posting guide!
"www.R-project.org/posting-guide.html", and try some of the things
suggested there.  In particular, if you haven't already, try RSiteSearch
for "nlme degrees of freedom" and anything else that seems relevant to
you.  Also, before your next post, I encourage you to try to develop the
simplest, self-contained example that illustrates your question.  I
believe you will more likely receive faster, more useful replies if you
make it easier for people to help you.

          hope this helps,
          spencer graves

gabriela escati peñaloza wrote:

> Dear Dr. Bates,
> Thank you very much for your response. I had consulted
> the algorithm described in Pinheiro and Bates.
> However, what I don't understand (among other things)
> is why my two parameters appear to be estimated at
> different grouping levels (based on the DF values).
> Affect this different values of DF at the estimates
> parameters? The estimates fixed effects were get at
> the same level of grouping?
> I apreciate any response.
>
>
>
>
> Lic. Gabriela Escati Peñaloza
> Biología y Manejo de Recursos Acuáticos
> Centro Nacional Patagónico(CENPAT).
> CONICET
> Bvd. Brown s/nº.
> (U9120ACV)Pto. Madryn
> Chubut
> Argentina
>
> Tel: 54-2965/451301/451024/451375/45401 (Int:277)
> Fax: 54-29657451543
>
>
>
>
>
>
>
> ___________________________________________________________
> 1GB gratis, Antivirus y Antispam
> Correo Yahoo!, el mejor correo web del mundo
> http://correo.yahoo.com.ar
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html