On 2011-04-26 15:11, Joshua Wiley wrote:
Hi,
One way would be:
summary(nls.object)[["coefficients"]][, "Std. Error"]
If you have a hankering to do it yourself rather than go through the
summary formula, the code here will get you there:
getAnywhere("summary.nls")
If you are going to be doing it a lot, creating a little function might be nice:
se.coef.nls<- function(model) {
summary(model)[["coeffficients"]][, "Std. Error"]
}
se.coef.nls(yourmodel)
I have been doing something along those lines for a number of models.
Sadly, there is not a consistent name always given to the parameter or
coefficients table, so it will not quite be one size fits all, but
generally using str(), you can figure out what the names of what you
want are so it is not much trouble to get out.
I would generally use the coef() extractor function if
it's available (and it is for nls()). ?nls has an example:
coef(summary(fm1DNase1))
which is a matrix from which you can get the SEs:
coef(summary(fm1DNase1))[,"Std. Error"]
or
coef(summary(fm1DNase1))[, 2]
Schatzi,
As to your other question about 'adding two parameters', that
doesn't make sense to me. Can you provide a sensible example?
In any case you would no doubt have to look at the covariance
matrix of the parameter estimates (with vcov()).
Peter Ehlers
str(summary(yourmodel))
Cheers,
Josh
On Tue, Apr 26, 2011 at 11:21 AM, Schatzi<adele_thomp...@cargill.com> wrote:
How do I extract the standard error of the parameter estimates?
Also, if I would like to add two parameters together (x+y), can I use this
equation to calculate the new standard error?:
x = parameter 1
y = parameter 2
xSE = SE parameter 1
ySE = SE parameter 2
NewSE=(x+y)*sqrt((xSE/x)^2+(ySE/y)^2)
--
View this message in context:
http://r.789695.n4.nabble.com/How-can-I-extract-information-from-list-which-class-is-nls-tp804151p3476154.html
Sent from the R help mailing list archive at Nabble.com.
______________________________________________
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.
______________________________________________
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.
