Hello all,
I would like to get parameter estimates for different models. For one of
them I give the code in example. I am estimating the parameters (i,j and
k) with the nls function, which sees the error distribution as normal, I
would however like to do the same as nls with the assumption that the
errors are poisson distributed.
Is there a way to do this with R? Are there packages designed for this? I
tried with the gnm package, but don't understand how to transform my
equation to a generalised equation. Is there an option for nls to choose
family = poisson?
Lower in the mail the code with the model and visualisations I use to
check my results. I also copied the test dataset from my txt file.
I am using R 2.15 and Rstudio to visualise it.
plot(FR~N0)
x <-
nls(FR~(exp(i+j*N0)/(1+exp(i+j*N0)))*(k*N0/(k+N0)),start=list(i=0.02,j=0.002,k=6))
summary(x)
hatx <- predict(x)
lines(spline(N0,hatx))
N0 FR
10 2
10 3
10 2
10 4
10 2
10 2
10 1
10 2
10 2
10 2
20 2
20 3
20 3
20 3
20 4
20 2
20 4
20 2
20 3
20 2
30 1
30 2
30 3
30 4
30 5
30 6
30 2
30 3
30 2
30 2
40 2
40 3
40 3
40 6
40 5
40 4
40 3
40 3
40 2
40 3
50 4
50 5
50 2
50 3
50 7
50 5
50 4
50 3
50 4
50 5
60 5
60 6
60 8
60 4
60 4
60 3
60 2
60 2
60 5
60 4
Kind Regards
Joachim
Don't waste paper! Think about the environment before printing this e-mail
______________________________________
Joachim Audenaert
Adviesdienst Gewasbescherming
Proefcentrum voor Sierteelt
Schaessestraat 18
B-9070 Destelbergen
Tel. +32 9 353 94 71
Fax +32 9 353 94 95
E-mail: joachim.audena...@pcsierteelt.be
www.pcsierteelt.be
______________________________________
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
