dear Szymon,
what do you mean
"it does not work for others.. that fit within similar range"?
Each dataset has its own features and breakpoint estimation is not as
simple as estimation of linear models even if your data "fit within
similar range".
I will contact you out of the list for details,
best,
vito
Il 08/05/2012 16.44, Szymon Biskup ha scritto:
Hi everyone,
while trying to use 'segmented' (R i386 2.15.0 for Windows 32bit OS) to
determine the breakpoint I got stuck with an error message and I can't find
solution. It is connected with psi value, and the error says:
Error in seg.glm.fit(y, XREG, Z, PSI, weights, offs, opz) :
(Some) estimated psi out of its range
This is the code I am using:
library("segmented")
curva<-read.table("lamintr1.txt", header=T)
attach(curva)
fit.glm<-glm(gpp~temp, weight=NULL, family=gaussian)
plot(temp,gpp,xlab=expression("temp"),
ylab="gpp",pch=15,cex=0.8,xlim=c(0,50), ylim=c(0,40))
o1<-glm(gpp ~ temp, weight=NULL, family=gaussian)
os1<-segmented(o1, seg.Z=~temp, psi=15, control=seg.control(n.boot=0,
display=T, it.max=5))
plot(os1, add=TRUE, res=TRUE, se=FALSE, show.gap=TRUE, linkinv = FALSE,
res.col=1, rev.sgn=FALSE, const=0)
summary(os1)
And the most surprising fact is that it works for some of my data, eg:
temp gpp
5 5.08050857592085
10 9.50809597873546
15 21.0206415558052
20 21.5340216521042
25 22.8455243983385
30 17.6106786978697
but not for the others, that fit within similar range (in what case I tired to
change the psi value but it didn't help), eg:
temp gpp
5 10.1494724447878
10 9.64730588470101
15 19.3439579009423
20 20.6756229089911
25 13.7902544619339
30 21.9355758560751
or
temp gpp
5 8.64380785577685
10 9.47992535226006
15 16.7556554476544
20 14.5189937476639
25 20.6874556832793
30 17.5509059595314
I saw post with similar questons but none of them had the answer I am looking
for.
Would there be anyone that could help me with this?
Thanks a lot for your time and help.
Best regards,
Szymon
______________________________________________
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.
--
====================================
Vito M.R. Muggeo
Dip.to Sc Statist e Matem `Vianelli'
Università di Palermo
viale delle Scienze, edificio 13
90128 Palermo - ITALY
tel: 091 23895240
fax: 091 485726
http://dssm.unipa.it/vmuggeo
______________________________________________
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.
