Displaying 20 results from an estimated 10000 matches similar to: "Package 'nlme' linear mixed effects model error "unexpected symbol""
2011 Oct 04
1
Question about linear mixed effects model (nlme)
Hi,
I applied a linear mixed effect model in my data using the nlme package.
lme2<-lme(distance~temperature*condition, random=~+1|trial, data) and then
anova.
I want to ask if it is posible to get the least squares means for the
interaction effect and the corresponding 95%ci. And then plot this values.
Thank you
Panagiotis
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2007 Jun 20
2
Linear Mixed Models with nlme, more than one random effect
Hi, I' trying to learn how to use lme for Linear Mixed Models and I have a
problem when I have to include more than one random effect in my model. I
know that this could be a stupid question to ask, but I'm not able to solve
it by myself... One example: if my model is
response = operator + block + day
with operator and block as fixed effects and day as random effect, I use
res.lme
2009 May 11
1
Error in NLME (nonlinear mixed effects model)
Hi there,
I have been trying to fit an NLME to my data. My dataset has two category levels - one is a fixed effect (level1) and one is a random effect (level2), though so far I have only experimented with the highest level grouping (fixed, level1), with the following code:
mod1 <- nlme(H ~ a*(1-exp(-b*D^c)),
data=sizes,
fixed=a+b+c~factor(Loc),
start=c(a=75,b=0.05,c=0.7))
This returns the
2005 Jun 30
1
Nolinear mixed-effects models (nlme)
Hello,
I am trying to fit a nonlinear model of the form of:
A*x^b*exp(-c*x)
This represents a lactation curve. I have a bunch of cows, so I want
COW to be a random effect.
I have been trying the following code with very littel success:
> fm1 <- nlme(yield ~ A*(DIM^B)*(exp(-C*DIM)),
+ data = group,
+ fixed = A + B + C ~ 1,
+ start = c(A = 20, B =
2001 May 16
2
nlme and "Mixed- Effects Models..." in Windows
(windows 98, R 1.2.3, ESS 5.1.18, nlme 3.1 from CRAN)
Dear R users,
I am trying to follow Pinheiro and Bates book ("Mixed-Effects Models in S
and S-PLUS"). I downloaded the nlme package from CRAN, and unzipped all the
data and help files. Unfortunately, I cannot generate the figures in the
book. For instance, their appears to be no plot.design or intervals plotting
functions.
Have these
2005 Sep 16
1
Nolinear mixed-effects models (nlme)
Do you send information about lactation curve analyse with no linear mixed
model, with fixed effects (herd, year season, parity) and random effects
(cow)?.
Than you very much
Mario Fernando
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2011 Jul 25
2
Wide confidence intervals or Error message in a mixed effects model (nlme)
I am analyzing a dataset on the effects of six pesticides on population
growth rate of a predatory mite. The response variable is the population
growth rate of the mite (ranges from negative to positive) and the
exploratory variable is a categorical variable (treatment). The
experiment was blocked in time (3 blocks / replicates per block) and it
is unbalanced - at least 1 replicate per block. I am
2013 Feb 22
1
How to do generalized linear mixed effects models
I want to analyze binary, multinomial, and count outcomes (as well as
the occasional continuous one) for clustered data.
The more I search the less I know, and so I'm hoping the list can
provide me some guidance about which of the many alternatives to choose.
The nlme package seemed the obvious place to start. However, it seems
to be using specifications from nls, which does non-linear
2013 Jan 23
1
mixed effects meta-regression: nlme vs. metafor
Hi,
I would like to do a meta-analysis, i.e., a mixed-effects regression,
but I don't seem to get what I want using both the nlme or metafor packages.
My question: is there indeed no way to do it?
And if so, is there another package I could use?
Here are the details:
In my meta-analysis I'm comparing different studies that report a
measure at time zero and after a certain followup
2003 Oct 04
2
mixed effects with nlme
Dear R users:
I have some difficulties analizing data with mixed effects NLME and the
last version of R. More concretely, I have a repeated measures design with
a single group and 2 experimental factors (say A and B) and my interest is
to compare additive and nonadditive models.
suj rv A B
1 s1 4 a1 b1
2 s1 5 a1 b2
3 s1 7 a1 b3
4 s1 1 a2
2011 Oct 07
1
"r squared" and anova for linear mixed-effects model
I have a linear
mixed-effects model (from the package
nlme) with a random effect; Is there something like
an "r squared" for the whole
model which I can state? I´d like to kown: How would I do anova for a linear
mixed-effects model?
Lic. Florencia BonattoUniversidad Nacional de Rio Cuarto, Cordoba.
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2006 Oct 16
1
linear mixed effects models with breakpoints
Hi folks
I have some data to which I've been fitting linear mixed effects
models. I am currently using a lme model in the nlme package, with terms
for random effects due to repeated measures on individuals and the
corCAR1 serial correlation structure. However, there is some suggestion
in the data (and from theory) that a breakpoint (change point) model may
be more appropriate. Scott, Norman
2012 Sep 14
1
linear mixed-effects models with two random variables?
Dear R users,
Does anyone knows how to run a glmm with one fixed factor and 2 random
numeric variables (indices)? Is there any way to force in the model a
separate interaction of those random variables with the fixed one?
I hope you can help me.
#eg.
Reserve <- rep(c("In","Out"), 100)
fReserve <- factor(Reserve)
DivBoulders <- rep
2007 Oct 22
2
Repeated Measures/Linear Mixed Effects function
I have three columns of data, Xc, Trt and fish. This was a repeated
measures design with 6 measurements taken from each of 5 fish. Xc is the
actual measurement, Trt is the treatment, and fish is the fish number. Data
can be seen below (hopefully it is in the column format). I would like to
look for differences between treatments in a repeated measures format. I
used the following code
2010 Aug 12
0
termplot for mixed linear effects models
Is there an equivalent package for mixed linear effects models developed using the package "nlme" as there is for linear models?
Tschüß
Tony Meissner
Principal Scientist (Monitoring/Statistics)
Resource Monitoring
Science, Monitoring and Information Division
Department for Water
"Imagine" ©
*(ph) (08) 8595 2209
*(mob) 0401 124 971
*(fax) (08) 8595 2232
* 28 Vaughan Terrace,
2008 Jan 31
0
How to calculate Intraclass-coefficient in 2-level Linear Mixed-Effects models?
Dear R-users,
consider a 2-level linear mixed effects model (LME) with random intercept
AND random slope for level 1 AND 2. Does anybody know how to calculate
Intraclass-coefficient (ICC) for highest (innermost) level 2 ??? In the
literature, I did not find an example for these kind of komplex models.
For 1-level Random-Intercept models it would be easy:
ICC = variance due to the clustering
2008 Nov 10
2
is there a way to use "aov" to do mixed linear models with both random and fixed effects?
if I do:
yyy=aov(Y~A*B*C);
it seems that the three way ANOVA is based on all fixed-effects.
There is no way to signal to "aov" the A and B are random effects and
C is fixed effect; or A is random and B and C are fixed?
Moreover, I guess I will need the Expected Mean Squares in order to do
the F-test, where can I obtain these Expected Mean Squares in R?
And is there a command that
2010 Jan 23
1
(nlme, lme, glmmML, or glmmPQL)mixed effect models with large spatial data sets
Hi,
I have a spatial data set with many observations (~50,000) and would like to
keep as much data as possible. There is spatial dependence, so I am
attempting a mixed model in R with a spherical variogram defining the
correlation as a function of distance between points. I have tried nlme,
lme, glmmML, and glmmPQL. In all case the matrix needed (seems to be
(N^2)/2 - N) is too large for my
2004 Aug 19
0
NLME: Holding constant the across group correlational structure of the fixed effects in nlme
Hello all.
I was wondering if there is a way to hold constant the fixed effects correlation structure across multiple groups?
For example, I have two groups and I fit a three parameter logistic growth curve where the fixed effects are free to vary across the groups. I'll paste in the code as a concrete example:
> Result.NLME <- nlme(Score ~ SSlogis(Time, Asym, xmid, scal),
+
2009 Jul 10
1
Degree of freedom in the linear mixed effect model using lme function in R
Hello,
I would appreciate if somebody could help me clear my mind about the below issues.
I have a factorial experiment to study the effects of Grazing and Fire on Forest biomass production. The experimental unit (to which the treatment combinations are applied) are PLOTs. The measures were made repeatedly for 13 years.
I am planning to use the linear mixed effect model function lme in R for this.