Dear Cyrille,
type "?nls" in the R command line.
This will show you how to use the nls function.
And please read the "posting guide" (see bootom of each message).
This will help you to get more helpful answers.
Best wishes,
Arne
On Monday 15 November 2004 14:42, BARNERIAS Cyrille
wrote:> Hello,
>
> I am beginning with R and I would like to test a non linear model. But I do
> not find exactly wath I am looking for in nls packages (or I do not know
> where to search).
> I would like to try a model like this : y=b * x exp(n)/(a exp(n) + x exp
> (n))
> Where
> a = a0 + a1z
> b= b0 + b1z
> x and z are variables
> y the variable that I am trying to modelise
> a0, a1, b0 and b1 are parameters to determine.
> I am wondering if I can use nls and if so how do I have to write my command
> ?
> Thanks in advance for your help.
>
> Cyrille Barn??rias
> Adjoint au chef d'??chelon interr??gional de Caen
> Inventaire forestier national
> 73 rue Marie Curie
> 14 200 H??rouville Saint-Clair
> France
> Tel : 02.31.47.71.53
>
> ______________________________________________
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> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
--
Arne Henningsen
Department of Agricultural Economics
University of Kiel
Olshausenstr. 40
D-24098 Kiel (Germany)
Tel: +49-431-880 4445
Fax: +49-431-880 1397
ahenningsen at agric-econ.uni-kiel.de
http://www.uni-kiel.de/agrarpol/ahenningsen/