Displaying 20 results from an estimated 2000 matches similar to: "nlsList{nlme} control of min and max parameter bounds?"
2010 Apr 15
0
nlsList {nlme} - control arguments problem
Hi Rick
Thanks to Dieter Menne I did manage to solve the problem of imposing bounds on
the parameter space duirng an nlsList fit. He suggested using optim to optimize
the parameters prior to each fit. This worked well for me as I had a customized
selfStart function that then optimized the parameters for each individual
separately.
if you rewrote your selfStart function as:
powrDpltInit <-
2006 Feb 12
1
lme, nlsList, nlsList.selfStart
Dear listers,
I am trying to fit a model using nlsList() using alternately a SSfol()
selfstart function or its developped equivalent formulae.
This preliminary trial works well
mydata<-groupedData(Conc~Tps|Organ,data=mydata)
mymod1<-nls(Conc~SSfol(Dose,Tps,lKe,lKa,lCl),data=mydata)
as well as a developped form:
mymod2<-nls(Conc~Dose * exp(lKe+lKa-lCl) *
2006 Feb 01
1
Passing additional paramaters to nlsList(nlme) fit function
Hello, nls-users,
is it possible to pass additional parameters to the model function that are
known and groupwise constant with nlsList? I could not find something like a
"keep this fixed" option in the documentation and the code (my fault...?)
The current workaround is to break the problem down into groups and use
globals to pass the constant parameters, but it is ugly code and
2004 Jul 01
2
Individual log likelihoods of nlsList objects.
Hello all.
I was wondering if the logLike.nls() and logLike.nlme() functions are still
being used. Neither function seems to be available in the most recent
release of R (1.9.1). The following is contained in the help file for
logLik(): "classes which already have methods for this function include:
'glm', 'lm', 'nls' and 'gls', 'lme' and others in
2008 Jan 25
1
nlsList (nlme) error
Hi All.
I'm trying to run nlsList an getting an error that makes no sense to
me. I have accuracy and reaction time data over many trials for each
person (id)
When I use nlsList code that is virtually identical to the example in
the doc file I get the following error. I've tried everything I could
think of and can't get around it. Any ideas what I'm doing wrong?
**************
2009 Jun 29
0
nlsList {nlme} - control arguments problem
Hi All.
I'd like to send some control arguments to the nls function when
performing a nlsList analysis.
I'm fitting a power model to some grouped data and would like to
impose lower bounds on the estimates using the "port" algorithm.
Obtaining the lower bound constraint works fine with a direct call to
nls for a single level of the grouping variable. ?However, the bounds
2008 Mar 26
1
Compare parameter estimates of a nlsList object
Hello together,
Is there a tool to test the statistical differences between parameter estimates of a nlsList fit?
I fitted degradation data using the nlsList method and want to find out whether derived rate constants are significantly different from each other at the grouping factors soil and temperature.
Regards
Frank Scherr
2007 Jun 14
0
nlsList problems: control option does not effect output and strange environment search
Dear R-helpers,
I'm using R 2.5.0 under Windows and am trying to use nlsList from nlme
3.1-80 with the selfstart function for the four parametric logistic
function. My first test went well, but now I'm trying to do some more
sophisticated things and it does not work anymore.
I simulate my data from a five parametric logistic function like this:
2009 Jun 12
1
Function for AIC or logLIK for nlsList object
Dear R users,
Does anybody have a function to calculate logLik or AIC for nlsList objects? After receiving error messages, another user helped me ascertain that this function is not currently written into R.
Many thanks
Lindsay
2002 Aug 13
1
nlsList
Dear all,
is there a way to extract the individual variance-covariance matrix
of the parameter estimates of the i-th individual using nlsList ?
Thanks a lot
Peter
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2005 Nov 09
0
source of "susbcript out of bounds error" in nmle
A few days ago I posted a question to this discussion group concerning
to origin of an error message < subscript out of bounds > while using
the nonlinear mixed model (nlme) function in R with a self-starting
function. Thanks for those who responded. This posting is to explain
what (I think) it causing the error.
Pinheiro & Bates (2000, pages 342-347) describe how to construct a
2007 Apr 20
1
nlme trouble
I am not certain how nlme works so I followed an example from the web (
http://www.menne-biomed.de/gastempt/gastempt1.html). I was able to
successfully reproduce the example. However, when I modified my the example
to use my data and with my formula, I get a set of errors having to do with
the log() function. I get 10 of them (all exactly the same) and there are 10
levels in my factor variable.
2007 Aug 23
0
Lost in substitute: nlsList and nlme with dynamic formula
DeaR
I am trying to use a dynamically create formula with nlsList and nlme, but I
cannot get the environment of the string-generated formal to work similarly
to the manually entered one.
Any idea?
Dieter
#-----
library(nlme)
# Pinheiro/Bates p 280
fm1Indom.lis = nlsList(conc~SSbiexp(time,A1,lrc1,A2,lrc2),
data=Indometh)
nlme(fm1Indom.lis,random=pdDiag(A1+lrc1+A2~1))
# works...
# Simulating
2004 Feb 23
0
Question concerning functions nlsList and nlme from nlme R library.
I hope that the mailing list is the correct forum for the question below. I
have trouble calling functions nlsList and nlme from
another function. Any help would be greatly appreciated.
Jens Praestgaard
Human Genome Sciences
Rockville MD.
I have a data set v with two components, v$mixeddat and v$init. They are
listed below:
> v$mixeddat
conc result rep sample z
11 20.00000000
2004 Mar 23
1
nlme question
I have a need to call and pass arguments to nlme() from within another
function. I use R version 1.8.
I have found an apparent way to make this work, but I would appreciate
some comments on whether this fix is really appropriate, or there is
another way to do it that does not involve changing the source code. I
don't have enough experience to start changing the sorurce code of a
library
2017 Nov 09
1
Sharing an R installation via NFS on ubuntu cluster
I can install R with
sudo apt-get update
sudo apt-get install r-base
this is not my problem, and indeed, not my question. my question was how
could I share the resulting R installation over NFS? Do I have to export
every location where apt-get installs a component or can I force apt-get to
place the installation in a certain location?
On 8 November 2017 at 17:37, Ista Zahn <istazahn at
2009 Oct 17
1
custom selfStart model works with getInitial but not nls
Hello,
I'm having problems creating and using a selfStart model with nlme. Briefly,
I've defined the model, a selfStart object, and then combined them to make a
selfStart.default model.
If I apply getInitial to the selfStart model, I get results. However, if I try
usint it with nls or nlsList, these routines complain about a lack of initial
conditions.
If someone could point out
2008 Feb 19
0
nlsList - Error in !unlist(lapply(coefs, is.null))
Howdee,
I am able to fit a 4-parameter logistic growth curve to a dataset which
comprise many individuals (using R v. 2.3.1). Yet, if I want to obtain the
parameters for each individual (i.e., for each 'id') using nlsList, then I
obtain an Error message which I have trouble interpreting. Any advice as to
how I can solve this problem?
Thanks for your time,
Marc
> reg <-nls(mass ~
2009 Jan 26
0
why two diff. se in nlsList?
Hi list,
In the object returned by summary.nlsList, what's the difference between "coefficients" and "parameters"? The have the same "Estimate", different se (therefore t value), but same p values.
R.2.8.0 on winxp with nlme_3.1-89
Thanks,
...Tao
+++++++++++++++++++++++++++++++++++++++++++++++++
> library(nlme)
> fm1 <- nlsList(uptake ~
2004 Nov 25
1
Error in anova(): objects must inherit from classes
Hello:
Let me rephrase my question to attract interest in the problem I'm having. When I appply anova() to two equations
estimated using glmmPQL, I get a complaint,
> anova(fm1, fm2)
Error in anova.lme(fm1, fm2) : Objects must inherit from classes "gls",
"gnls" "lm","lmList", "lme","nlme","nlsList", or "nls"