Displaying 20 results from an estimated 2000 matches similar to: "lme convergence"
2006 May 26
2
lme, best model without convergence
Dear R-help list readers,
I am fitting mixed models with the lme function of the nlme package.
If I get convergence depends on how the method (ML/REM) and which (and
how much) parameters will depend randomly on the cluster-variable.
How get the bist fit without convergence?
I set the parameters msVerbose and returnObject to TRUE:
lmeControl(maxIter=50000, msMaxIter=200, tolerance=1e-4,
2006 Sep 07
5
augPred plot in nlme library
All,
I'm trying to create an augPred plot in the nlme library, similar to the
plot on
p.43 of Pinheiro & Bates (Mixed Effects Models in S and S-Plus) for
their Pixel data.
My data structure is the same as the example but I still get the error
msg below.
> comp.adj.UKV <- groupedData(adj.UKV ~ Time | Patient_no/Lisinopril,
data = comp.adj.UKV.frm, order.groups = F)
>
2006 Feb 15
1
no convergence using lme
Hi. I was wondering if anyone might have some suggestions about how I can
overcome a problem of "iteration limit reached without convergence" when
fitting a mixed effects model.
In this study:
Outcome is a measure of heart action
Age is continuous (in weeks)
Gender is Male or Female (0 or 1)
Genotype is Wild type or knockout (0 or 1)
Animal is the Animal ID as a factor
2003 Sep 16
2
gnls( ) question
Last week (Wed 9/10/2003, "regression questions") I posted
a question regarding the use of gnls( ) and its dissimilarity
to the syntax that nls( ) will accept. No one replied, so
I partly answered my own question by constructing indicator
variables for use in gnls( ). The code I used to construct
the indicators is at the end of this email.
I do have a nagging, unanswered
2008 Jun 14
1
"False convergence" in LME
I tried to use LME (on a fairly large dataset, so I am not including it), and I got this error message:
Error in lme.formula(formula(paste(c(toString(TargetName), "as.factor(nodeInd)"), :
nlminb problem, convergence error code = 1
message = false convergence (8)
Is there any way to get more information or to get the potentially wrong estimates from LME?
(Also, the page in the
2007 Nov 09
1
Confidence Intervals for Random Effect BLUP's
I want to compute confidence intervals for the random effect estimates
for each subject. From checking on postings, this is what I cobbled
together using Orthodont data.frame as an example. There was some
discussion of how to properly access lmer slots and bVar, but I'm not
sure I understood. Is the approach shown below correct?
Rick B.
# Orthodont is from nlme (can't have both nlme and
2002 Dec 17
1
lme invocation
Hi Folks,
I'm trying to understand the model specification formalities
for 'lme', and the documentation is leaving me a bit confused.
Specifically, using the example dataset 'Orthodont' in the
'nlme' package, first I use the invocation given in the example
shown by "?lme":
> fm1 <- lme(distance ~ age, data = Orthodont) # random is ~ age
Despite the
2003 Mar 04
2
How to extract R{i} from lme object?
Hi, lme() users,
Can some one tell me how to do this.
I model Orthodont with the same G for random
variables, but different R{i}'s for boys and girls, so
that I can get sigma1_square_hat for boys and
sigma2_square_hat for girls.
The model is Y{i}=X{i}beta + Z{i}b + e{i}
b ~ iid N(0,G) and e{i} ~ iid N(0,R{i}) i=1,2
orth.lme <- lme(distance ~ Sex * age, data=Orthodont,
random=~age|Subject,
2010 Oct 25
1
building lme call via call()
dear all,
I would like to get the lme call without fitting the relevant model.
library(nlme)
data(Orthodont)
fm1 <- lme(distance ~ age, random=list(Subject=~age),data = Orthodont)
To get fm1$call without fitting the model I use call():
my.cc<-call("lme.formula", fixed= distance ~ age, random = list(Subject
= ~age))
However the two calls are not the same (apart from the data
2006 Jul 24
3
standardized random effects with ranef.lme()
Using ranef() (package nlme, version 3.1-75) with an 'lme' object I can
obtain random effects for intercept and slope of a certain level (say:
1) - this corresponds to (say level 1) "residuals" in MLWin. Maybe I'm
mistaken here, but the results are identical.
However, if I try to get the standardized random effects adding the
paramter "standard=T" to the
2006 Jul 23
1
How to pass eval.max from lme() to nlminb?
Dear R community,
I'm fitting a complex mixed-effects model that requires numerous
iterations and function evaluations. I note that nlminb accepts a
list of control parameters, including eval.max. Is there a way to
change the default eval.max value for nlminb when it is being called
from lme?
Thanks for any thoughts,
Andrew
--
Andrew Robinson
Department of Mathematics and Statistics
2009 Mar 23
1
Extracting SD of random effects from lme object
Hello,
How do I get the standard deviations for the random effects out of the
lme object? I feel like there's probably a simple way of doing this,
but I can't see it. Using the first example from the documentation:
> fm1 <- lme(distance ~ age, data = Orthodont) # random is ~ age
> fm1
Linear mixed-effects model fit by REML
Data: Orthodont
Log-restricted-likelihood:
2006 Mar 21
1
Scaling behavior ov bVar from lmer models
Hi all,
To follow up on an older thread, it was suggested that the following
would produce confidence intervals for the estimated BLUPs from a linear
mixed effect model:
OrthoFem<-Orthodont[Orthodont$Sex=="Female",]
fm1OrthF. <- lmer(distance~age+(age|Subject), data=OrthoFem)
fm1.s <- coef(fm1OrthF.)$Subject
fm1.s.var <- fm1OrthF. at bVar$Subject
fm1.s0.s <-
2005 Dec 22
2
bVar slot of lmer objects and standard errors
Hello,
I am looking for a way to obtain standard errors for emprirical Bayes estimates of a model fitted with lmer (like the ones plotted on page 14 of the document available at http://www.eric.ed.gov/ERICDocs/data/ericdocs2/content_storage_01/0000000b/80/2b/b3/94.pdf). Harold Doran mentioned (http://tolstoy.newcastle.edu.au/~rking/R/help/05/08/10638.html) that the posterior modes' variances
2012 Feb 05
1
Covariate model in nlme
Dear R users,
I am using nlme to fit a pharmacokinetic model. The base model is
parameterized in terms of CL, V1, V2 and Q.
basemodel<-nlme(Conc ~TwoCompModel(CL,Q,V1,V2,Time,ID),
data = data2, fixed=list(CL+Q+V1+V2~1),
random = pdDiag(CL+V1+V2~1),
start=c(CL=log(20),Q=log(252),V1=log(24.9),V2=log(120)),
control=list(returnObject=TRUE,msVerbose=TRUE,
msMaxIter=20,pnlsMaxIter=20,pnlsTol=1),
2004 Aug 27
2
degrees of freedom (lme4 and nlme)
Hi, I'm having some problems regarding the packages
lme4 and nlme, more specifically in the denominator
degrees of freedom. I used data Orthodont for the two
packages. The commands used are below.
require(nlme)
data(Orthodont)
fm1<-lme(distance~age+ Sex,
data=Orthodont,random=~1|Subject, method="REML")
anova(fm1)
numDF DenDF F-value p-value
(Intercept) 1
1999 Jun 02
1
lme problem ?
Dear friends. I tried the session below with 10 MB in both vsize and nsize but didn't get the
example work. Is this a problem in LME or in me or both or somewhere else or undefined ?
R : Copyright 1999, The R Development Core Team
Version 0.64.0 Patched (May 3, 1999)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type
2005 Sep 29
1
plot.augPred sorted and labelled according second factor
Hi
using this code example:
library(nlme)
fm1 <- lme(Orthodont, random = ~1)
plot(augPred(fm1))
is there any way to have the plots in each cell labelled and ordered
according to Orthodont$Sex? I.e. in addition to the bar with the label for
Orthodont$Subject there is another bar labelling the Sex of the subject?
thanks a lot
christoph
--
2007 Nov 01
1
A question about lme object
I have a question about the lme function in R. My question is: After I got
the object from function lme, why the numIter value of the object is always
NULL? Following is my code:
jjww<-lme(y~x*zz,data=simul,random=~x|group,
control=lmeControl(returnObject=TRUE))
attributes(jjww)
jjww$numIter
the first 20 observation of data simul are:
> simul
y
2006 Apr 25
1
summary.lme: argument "adjustSigma"
Dear R-list
I have a question concerning the argument "adjustSigma" in the
function "lme" of the package "nlme".
The help page says:
"the residual standard error is multiplied by sqrt(nobs/(nobs -
npar)), converting it to a REML-like estimate."
Having a look into the code I found:
stdFixed <- sqrt(diag(as.matrix(object$varFix)))
if (object$method