Displaying 20 results from an estimated 1100 matches similar to: "binomia data and mixed model"
2005 Jan 06
1
GLMM and crossed effects
Hi again. Perhaps a simple question this time....
I am analysing data with a dependent variable of insect counts, a fixed
effect of site and two random effects, day, which is the same set of 10
days for each site, and then transect, which is nested within site (5
each).
I am trying to fit the cross classified model using GLMM in lme4. I
have, for potential use, created a second coding
2005 Feb 01
4
Split-split plot ANOVA
Does someone out there have an example of R-code for a split-split plot ANOVA using aov or another function? The design is not balanced. I never set up one in R before and it would be nice to see an example before I tackle a very complex design I have to model.
Thanks,
Mike
Mike Saunders
Research Assistant
Forest Ecosystem Research Program
Department of Forest Ecosystem Sciences
University of
2007 Aug 22
4
within-subject factors in lme
I don't think, this has been answered:
> I'm trying to run a 3-way within-subject anova in lme with 3
> fixed factors (Trust, Sex, and Freq), but get stuck with handling
> the random effects. As I want to include all the possible random
> effects in the model, it would be something more or less
> equivalent to using aov
>
> > fit.aov <- aov(Beta ~
>
2004 Jun 15
2
multiple error strata in aov
I am trying to perform a model 3 ANOVA for a 2 factor (say factor A and
factor B) anova in which factor A is fixed and factor B is random.
Therefore, the error term for the test of factor A should be the A:B
interaction term and the error terms for B and A:B should be the model
residual (within) term. I have tried to work out how to specify such
error strata using aov, however, I have had
2005 Oct 19
1
anova with models from glmmPQL
Hi !
I try to compare some models obtained from glmmPQL.
model1 <-
glmmPQL(y~red*yellow+I(red^2)+I(yellow^2)+densite8+I(densite8^2)+freq8_4
+I(freq8_4^2), random=~1|num, binomial);
model2 <-
glmmPQL(y~red*yellow+I(red^2)+I(yellow^2)+densite8+I(densite8^2)+freq8_4
, random=~1|num, binomial);
anova(model1, model2)
here is the answer :
Erreur dans anova.lme(model1, model2) : Objects must
2008 Jan 29
1
Guidance for reporting results from lme test?
En innebygd og tegnsett-uspesifisert tekst ble skilt ut...
Navn: ikke tilgjengelig
Nettadresse: https://stat.ethz.ch/pipermail/r-help/attachments/20080129/5f8a6ac4/attachment.pl
2005 Feb 14
1
testing equality of variances across groups in lme?
Hello. I am fitting a two-level mixed model which assumes equality of
variance in the lowest-level residuals across groups. The call is:
fit3<-lme(CLnNAR~CLnRGR,data=meta.analysis,
+ na.action="na.omit",random=~1+CLnRGR|study.code)
I want to test the assumption of equality of variances across groups at
the lowest level. Can someone tell me how to do this? I know that one
2007 Aug 07
2
GLMM: MEEM error due to dichotomous variables
I am trying to run a GLMM on some binomial data. My fixed factors include 2
dichotomous variables, day, and distance. When I run the model:
modelA<-glmmPQL(Leaving~Trial*Day*Dist,random=~1|Indiv,family="binomial")
I get the error:
iteration 1
Error in MEEM(object, conLin, control$niterEM) :
Singularity in backsolve at level 0, block 1
>From looking at previous help
2005 Jan 17
2
3d bar plot
This graph -> http://www.math.hope.edu/~tanis/dallas/images/disth36.gif
is an example I found at
http://www.math.hope.edu/~tanis/dallas/disth1.html
created by Maple.
Does anybody know how to create something similar in R?
I have a feeling it could be possible using scatterplot3d
(perhaps with type=h, the fourth example in help('scatterplot3d')?),
but I cannot figure it out.
Thanks in
2005 Jan 31
3
Special paper for postscript
Hi, All;
When I generate a "special" paper postscript image larger than "a4" or
"letter" using R, I can only see one-page portion of all image, of course.
What will be the simple solution for this? Is there any way I can set the
bounding box information on the image? Or any other suggestions?
Thanks in advance;
Tae-Hoon Chung
2005 Feb 02
1
random effects in lme
Dear all,
Suppose I have a linear mixed-effects model (from the package nlme) with
nested random effects (see below); how would I present the results from
the random effects part in a publication?
Specifically, I?d like to know:
(1) What is the total variance of the random effects at each level?
(2) How can I test the significance of the variance components?
(3) Is there something like an
2007 Jan 08
2
Contrasts for ordered factors
Dear all,
I do not seem to grasp how contrasts are set for ordered factors. Perhaps someone can elighten me?
When I work with ordered factors, I would often like to be able to reduce the used polynomial to a simpler one (where possible). Thus, I would like to explicetly code the polynomial but ideally, the intial model (thus, the full polynomial) would be identical to one with an ordered factor.
2004 Apr 01
2
modelling nested random effects with interactions in R
Hi there
Please excuse this elementary question, but I have been fumbling with this for
hours and can't seem to get it right.
I have a nested anova, with random factor "lakefac" nested within
factor "fishfac" (fixed), with an additional fixed factor "Habfac". If I
consider everything as fixed effects, it's addmittedly not the correct model,
but I can at
2005 Oct 07
1
The mathematics inside lme()
Hello all!
Consider a dataset with a grouping structure, Group (factor)
Several treatments, Treat (factor)
Some sort of yield, Yield (numeric)
Something, possibly important, measured for each group; GroupCov (numeric)
To look for fixed effects from Treat on Yield, a first attempt could be:
m1 <- lm(Yield ~ Treat)
which gives, in a symmetric situation, the same estimated fixed effects as:
2004 Jun 11
2
lme newbie question
Hi
I try to implement a simple 2-factorial repeated-measure anova in the
lme framework and would be grateful for a short feedback
-my dependent var is a reaction-time (rt),
-as dependent var I have
-the age-group (0/1) the subject belongs to (so this is a
between-subject factor), and
-two WITHIN experimental conditions, one (angle) having 5, the other
3 (hands) factor-levels;
2007 Feb 19
1
random effect nested within fixed effects (binomial lmer)
I have a large dataset where each Subject answered seven similar
Items, which are binary yes/no questions. So I've always used Subject
and Item random effects in my models, fit with lmer(), e.g.:
model<-lmer(Response~Race+Gender+...+(1|Subject_ID)+(1|
Item_ID),data,binomial)
But I recently realized something. Most of the variables that I've
tested as fixed effects are properties
2005 Oct 10
1
interpretation output glmmPQL
Hi !
We study the effect of several variables on fruit set for 44 individuals
(plants). For each individual, we have the number of fruits, the number
of flowers and a value for each variable.
Here is our first model in R :
y <- cbind(indnbfruits,indnbflowers);
model1
<-glm(y~red*yellow+I(red^2)+I(yellow^2)+densite8+I(densite8^2)+freq8_4+I
(freq8_4^2), quasibinomial);
- We have
2008 Jan 29
1
Random and fixed effect model with a covariate
Dear All,
I wonder if anyone can please offer any advice on a model including 2 fixed effects and 1 random effect, as well as a covariate?
The experimental design is as follows:
I have a two by two factor design, where the two factors, Age (A) and Group size (G), both have 2 levels (old or young, and 1 or 3 respectively), and I am interested in the effect of these factors upon a continuous
2004 May 24
1
bug in cor (..., use= ...)?
Dear R users,
I have not found anything on this in the archives. Does anyone know whehther
the parameter use= is not functioning in cor or enlighten me what it is
supposed to do?
My R version is "R version 1.8.1, 2003-11-21" on Windows 2000. I am hoping
to be able to update to 1.9.1 as soon as it has appeared (we are not allowed
here to install software on our own and thus I am trying
2012 Jul 19
1
expert opinion on lmer
Hello,
I have the following design, counts were collected at different transects,
different depths and different sites at different times. Time is continuous
and assumed to be random, all the others are categorical fixed where
transect is nested within depth which is nested within site.
I would like an expert opinion about the following code where intercept is
modeled as random (I am not sure