Displaying 20 results from an estimated 10000 matches similar to: "Newbie with lme"
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 May 22
1
basic question on getGroups for lme analyses
Hi all!
I am working on a nested lme model with one fixed effect ("treatment", which 3 levels) and two random effects for "Individuals" (four of them) within "treatment" and "replicate -2 levels-" within "individual" within "treatment". For doing so, I´ve been trying to create a factor for Individual%in%Treatment, say IT
by
2005 Jan 05
2
lme: error message with random=~1
Hello,
I have an unbalanced mixed model design with two fixed effects
"site" (2 levels) and "timeOfDay" (4 levels) and two random effects
"day" (3 consecutive days) and "trap" (6 unique traps, 3 per site).
The dependent variable is the body length ("BL") of insect larvae from 7
to 29 individuals per trap (104 individuals in total).
To account
1999 Jun 15
2
ESS and R
For anybody who uses ESS with R, how do you invoke the vsize and nsize options
when you call R. I can't find any appropriate variables from an apropos.
Thanks,
Jord
--
Jordan Howarth CSIRO Mathematical and Information Sciences
mailto:jordan.howarth at cmis.csiro.au
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r-help mailing list -- Read
1999 Jul 01
1
lme
I am using rw0641.
In my continuing quest to understand repeated measures analysis, I again
return to lme. I exported the Potthoff and Roy data Orthodont.dat from
S-PLUS 4.5 to avoid capture errors and ran the examples in the R help. I
imported the data.frame with
data <- read.table("Orthodont.dat",header=T)
attach(data)
and created the objects
Orthodont.fit1 <-
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
2008 May 09
1
Using lme() inside a function
Dear R-help
I'm working on a large dataset which I have divided into 20 subsets
based on similar features. Each subset consists of observations from
different locations and I wish to use the location as a random effect.
For each group I want to select regressors by a stepwise procedure and
include a random effect on the intercept. I use stepAIC() and lme().
(The lmer()-function doesn't
2008 May 09
2
How can one make stepAIC and lme
Dear R-help
I'm working on a large dataset which I have divided into 20 subsets based on similar features. Each subset consists of observations from different locations and I wish to use the location as a random effect.
For each group I want to select regressors by a stepwise procedure and include a random effect on the intercept. I use stepAIC() and lme(). (The lmer()-function doesn't
2006 May 27
1
Recommended package nlme: bug in predict.lme when an independent variable is a polynomial (PR#8905)
Full_Name: Renaud Lancelot
Version: Version 2.3.0 (2006-04-24)
OS: MS Windows XP Pro SP2
Submission from: (NULL) (82.239.219.108)
I think there is a bug in predict.lme, when a polynomial generated by poly() is
used as an explanatory variable, and a new data.frame is used for predictions. I
guess this is related to * not * using, for predictions, the coefs used in
constructing the orthogonal
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,
2003 Jan 30
1
as.formula(string) and augPred in lme
Using formulas constructed from strings only
partially works for me in lme:
library(nlme)
data(Orthodont)
fm2<-lme(as.formula("distance~age"),data=Orthodont,random=~1|Subject)
summary(fm2) # works
augPred(fm2) # fails
#Error in inherits(object, "formula") :
#Argument "object" is missing, with no default
I assume that my use of as.formula is wrong, but
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)
>
2024 Sep 20
1
model.matrix() may be misleading for "lme" models
Dear r-devel list members,
I'm posting this message here because it concerns the nlme package,
which is maintained by R-core. The problem I'm about to describe is
somewhere between a bug and a feature request, and so I thought it a
good idea to ask here rather posting a bug report to the R bugzilla.
I was made aware (by Ben Bolker) that the car::Anova() method for "lme"
2009 Aug 03
2
lme funcion in R
Hi, R users,
I'm using the "lme" function in R to estimate a 2 level mixed effects
model, in which the size of the subject groups are different. It turned out
that It takes forever for R to converge. I also tried the same thing in SPSS
and SPSS can give the results out within 20 minutes. Anyone can give me some
advice on the lme function in R, especially why R does not converge?
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
2007 Jun 25
1
degrees of freedom in lme
Dear all,
I am starting to use the lme package (and plan to teach a course based on it
next semester...). To understand what lme is doing precisely, I used balanced
datasets described in Pinheiro and Bates and tried to compare the lme outputs
to that of aov. Here is what I obtained:
> data(Machines)
> summary(aov(score~Machine+Error(Worker/Machine),data=Machines))
Error: Worker
2008 Aug 28
1
Adjusting for initial status (intercept) in lme growth models
Hi everyone, I have a quick and probably easy question about lme for this
list.
Say, for instance you want to model growth in pituitary distance as a
function of age in the Orthodont dataset.
fm1 = lme(distance ~ I(age-8), random = ~ 1 + I(age-8) | Subject, data =
Orthodont)
You notice that there is substantial variability in the intercepts (initial
distance) for people at 8 years, and that
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:
2019 Jan 17
3
long-standing documentation bug in ?anova.lme
tl;dr anova.lme() claims to provide sums of squares, but it doesn't. And
some names are misspelled in ?lme. I can submit all this stuff as a bug
report if that's preferred.
?anova.lme says:
When only one fitted model object is present, a data frame with
the sums of squares, numerator degrees of freedom, denominator
degrees of freedom, F-values, and P-values
The output of
fm1
2005 Feb 16
2
Positive log-likelihood in lme
Kia ora
I'm a using lme (from nlme package) with data similar to the Orthodont dataset and am getting positive log-likelihoods (>100). This seems usual and I wondered if someone could offer a possible explanation.
I can supply a sample dataset if requested, but I feel almost certain that this question has been asked and answered recently. However, I can find no trace of it in the mail