Displaying 20 results from an estimated 8000 matches similar to: "multiple error strata in aov"
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 ~
>
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
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
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
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
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;
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
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
2005 Jan 27
1
binomia data and mixed model
Hi,
I am a first user of R.
I was hoping I could get some help on some data I need to analyze.
The experimental design is a complete randomized design with 2 factors (Source
material and Depth). The experimental design was suppose to consist of 4
treatments replicated 3 time, Source 1 and applied at 10 cm and source 2
applied at 20 cm. During the construction of the treatmetns the depths vary
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
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
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:
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
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
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.
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 Jan 10
2
Multiple comparisons following nlme
Dear Madam or Sir,
I need to do multiple comparisons following nlme analysis (Compare the
effects of different treatments on a response measured repeatedly over time;
fixed = response ~ treat*time). On the web I found the notion that one might
use the L argument from ANOVA. Do you have an example to show how this works
together with nlme? Are there other ways to do a post-hoc analysis in
2006 Oct 05
1
lmer BIC changes between output and anova
list,
i am using lmer to fit multilevel models and trying to use anova to compare the models. however, whenever i run the anova, the AIC, BIC and loglik are different from the original model output- as below. can someone help me out with why this is happening? (i'm hoping the output assocaited with the anova is right!).
thank you,
darren
> unconditional<-lmer(log50 ~ 1 + (1 |