R help - Dec 2007 - confidence intervals for y predicted in non linear regression

Hi, I´m trying to plot a nonlinear regresion with the confidence bands for
the curve obtained, similar to what nlintool or nlpredci functions in Matlab
does, but I no figure how to. In nls the option is there but not implemented
yet.

Is there a plan to implement the in a relative near future?

Thanks in advance, Florencio 



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On Tue, 4 Dec 2007, Florencio Gonz?lez wrote:
>
> Hi, I?m trying to plot a nonlinear regresion with the confidence bands for
> the curve obtained, similar to what nlintool or nlpredci functions in
Matlab
> does, but I no figure how to. In nls the option is there but not
implemented
> yet.
>
> Is there a plan to implement the in a relative near future?
No (and it is confidence intervals not confidence bands that are 
unimplemented, and have been for years).

Doing what you ask (confidence bands) is very tricky indeed to do 
accurately (and is not what nlpredci says it does), and even accurate 
pointwise confidence intervals are problematic.  See MASS4 sections 
8.4/5 and its on-line complements for some details about why even 
confidence intervals for parameters are frequently tricky in non-linear 
models.

You could use resampling methods: see the reference in the previous 
paragraph.
> Thanks in advance, Florencio
>
> 	[[alternative HTML version deleted]]
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

hi, hi all,

you can consult these links:
http://finzi.psych.upenn.edu/R/Rhelp02a/archive/43008.html
https://stat.ethz.ch/pipermail/r-help/2004-October/058703.html

hope this help


pierre


Selon Florencio Gonz?lez <florencio.gonzalez at GI.IEO.ES>:
>
> Hi, I?m trying to plot a nonlinear regresion with the confidence bands for
> the curve obtained, similar to what nlintool or nlpredci functions in
Matlab
> does, but I no figure how to. In nls the option is there but not
implemented
> yet.
>
> Is there a plan to implement the in a relative near future?
>
> Thanks in advance, Florencio
>
>
>
> La informaci?n contenida en este e-mail y sus ficheros adjuntos es
totalmente
> confidencial y no deber?a ser usado si no fuera usted alguno de los
> destinatarios. Si ha recibido este e-mail por error, por favor avise al
> remitente y b?rrelo de su buz?n o de cualquier otro medio de
almacenamiento.
>  This email is confidential and should not be used by anyone who is not the
> original intended  recipient. If you have received this e-mail in  error
> please inform the sender and delete it from  your mailbox or any other
> storage mechanism.
> 	[[alternative HTML version deleted]]
>
>