Displaying 3 results from an estimated 3 matches for "nraia".
2009 Aug 17
1
[Fwd: Re: R code to reproduce (while studying) Bates & Watts 1988]]]
Kevin Wright wrote:
> library(nlme)
> m2 <- gnls(conc ~ t1*(1-t2*exp(-k*time)),
> data = df.Chloride,
> start = list(
> t1 = 35,
> t2 = 0.91,
> k = 0.22))
So my error was to use nls instead that gnls. Thanks a lot, Kevin.
> summary(m2)
> plot(m2)
> lag.plot(resid(m2), do.lines=FALSE)
>
2010 Feb 03
1
comparison of parameters for nonlinear regression
Hi,
I have two series of data set (it's measurment of growth but under two
different conditions).
To model these data I use the same function which is :
formula <- y ~ Asym_inf + Asym_sup * ( (1 / (1 + (n1 * (exp( (tmid1-x)
/ scal1) )^(1/n1) ) ) ) - (1 / (1 + (n2 * (exp( (tmid2-x) / scal2)
)^(1/n2) ) ) ) )
After the estimation of the parameters thanks to "nls", I have 2
2011 May 17
0
Help fit 5 nonlinear models. - Plant growth curves
...ge the following
data with 5 nonlinears models that i evaluated.
Firtly, i send my data (totalsinatipicos) that i just try to fit with
the nonlinear models.
Next, i have the following script where i called the data as
totalsinatipicos. I made selfstarting each nonlinear model.
###Library
library(NRAIA)
###Data
d<-totalsinatipicos
f=unique(d$TRAT)
dia=unique(d$DDT)
REG=4:15
###Models
monomolecular=function(x,a,b,c){return(a*(1-exp(-b*(x-c))))}
gompertz=function(x,a,b,c){return(a*exp(-exp(-b*(x-c))))}
logistico=function(x,a,b,c){return(a/(1+exp(-b*(x-c))))}
gauss=function(x,a,b,c){return(a*exp(...