Displaying 20 results from an estimated 9000 matches similar to: "lmer"
2007 Mar 13
1
lme4 and mcmcamp
Dear R users
I am trying to obtain p-values for (quasi)poisson lmer models, using
Markov-chain Monte Carlo sampling and the command summary.
>
> My problems is that p values derived from both these methods are
totally different. My question is
(1) there a bug in my code and
>
(2) How can I proceed, left with these uncertainties in the estimations of
> the p-values?
>
> Below is
2005 Apr 25
2
residuals in lmer
Does anyone know how to extract residuals in lmer?
Here's the error I get:
>
crop.lme=lmer(response~variety*irrigation*pesticide+(1|rep)+(1|rep:
pesticide)+(1|rep:pesticide:irrigation), crop.data)
> qqnorm(crop.lme)
Error in qqnorm.default(crop.lme) : y is empty or has only NAs
> resid(crop.lme)
NULL
Thanks!
--Jake
2005 Dec 09
1
Residuals from GLMMs in the lme4 package
Hello there
This is the first time I have used r-help message board so I hope I have got
the right address.
I am trying to check the residuals of a GLMM model(run using the package
lme4). I have been able to check the residiuals of REMLs in lme4 using the
following:
m1<-lmer(vTotal~Week+fCollar+ (1|fCat), collars)
res<-resid(m1)
plot(res)
qqnorm(res)
library(MASS)
par(mfrow=c(2,3))
2007 Mar 12
2
Lmer Mcmc Summary and p values
Dear R users
I am trying to obtain p-values for (quasi)poisson lmer models, including
Markov-chain Monte Carlo sampling and the command summary.
>
> My problems is that p values derived from both these methods are
totally different. My question is
(1) there a bug in my code and
>
(2) How can I proceed, left with these uncertainties in the estimations of
> the p-values?
>
> Below
2008 Mar 03
1
Stepwise Multiple Regression
Dear R,
I am using stepwise multiple glm to select a subset of variables using the step command. My question is how do you calculate the percentage variance for each parameter in the reduced model. An example of my code thus far is,
fit<-glm(Abalone~offset(Area)+Sessile invertebrates+Bare rock+ NCA + Encrusting red algae, family = poisson ())
step(fit)
fit1<-glm(Abalone~offset(Area)+Bare
2002 Jul 02
0
error in plot residuals in a glm with iterations.
Hi,
I make this model:
> moths.m6 <-
glm(nind~metros+especie+habitat+metros:habitat+habitat:especie,family=poisson)
> anova(moths.m6,test="F")
Analysis of Deviance Table
Model: poisson, link: log
Response: nind
Terms added sequentially (first to last)
Df Deviance Resid. Df Resid. Dev F Pr(>F)
NULL 81 488.32
2007 Nov 12
0
Resid() and estimable() functions with lmer
Hi all,
Two questions:
1. Is there a way to evaluate models from lmer() with a poisson
distribution? I get the following error message:
library(lme4)
lmer(tot.fruit~infl.treat+def.treat+(1|initial.size),family=poisson)->model
plot(fitted(model),resid(model))
Error: 'resid' is not implemented yet
Are there any other options?
2. Why doesn't the function estimable() in gmodels
2006 Apr 20
1
lmer{lme4}, poisson family and residuals
Hello,
I’m trying to fit the following model:
Dependent variable: MAXDEPTH (the maximum depth reached by a penguin during
a given dive)
Fixed effects: SUCCESSMN (an index of the “individual quality” of a bird),
STUDYDAY (the day of the study, from -5 to 20, with 0=Dec 20), and the
interaction SUCCESSMN*STUDYDAY
Random effect: BIRD (the bird id, as each bird is performing several dives)
2007 Mar 02
1
Mitools and lmer
Hey there
I am estimating a multilevel model using lmer. I have 5 imputed datasets so
I am using mitools to pool the estimates from the 5
>
> datasets. Everything seems to work until I try to use
> MIcombine to produced pooled estimates. Does anyone have any suggestions? The betas and the standard errors were extracted with no problem so everything seems to work smoothly up until
2008 Feb 06
1
Mixed models quantile regression
Dear R,
I have a question concerning quantile regression models.
I am using the quantile regression model to test the relationship between
abalone and the percentage cover of algae etc at different sites and depths.
An example is
fit<-rq(abalone~%coversessileinvertebrates+factor(Depth)+factor(Site),tau=0.7)
In this model depth is fixed and site is random. My question is, is it
possible
2008 Mar 25
0
Mixed-effects models: question about the syntax to introduce interactions
hello everyone,
I would like to as for advice for the use of ?lmer?
(package ?lme4?) and writing the proper syntax to best
describe my data using a mixed-effects model.
I have just started to use these models, and although
I have read some good examples (Extending the Linear
Model with R, Faraway 2005; and the R book, Crawley
2007), I am still not sure of the syntax to test my
hypothesis.
2009 Apr 23
0
Problem to get a simple Analysis of Variance table with lmer()
Dear R users,
Is someone know how to get a simple analysis of variance table using other
random distribution than normal (ex: Poisson or Binomial)? When I try, I
recieved this message: (See my R code below)
--------------------- R response ----------------------------
Erreur dans anova(fit.poisson) :
single argument anova for GLMMs not yet implemented
OR
Erreur dans anova(fit.binomial) :
2006 Jan 10
0
bug in either glmmPQL or lme/lmer
I know it's conventional to report bugs to the maintainer, but I'm not sure
which package actually contains this bug(s), so I apologize for sending this
to the list at large. I see the bug under both R 2.1.1, and R 2.2.1. (I sent
a related message a while ago, but this one has more detail.)
library(MASS)
library(nlme)
fit.model <- function(il, model.family) {
cs <-
2005 Aug 18
1
Error messages using LMER
Dear All,
After playing with lmer for couple of days, I have to say that I am
amazed! I've been using quite some multilevel/mixed modeling packages,
lme4 is a strong candidate for the overall winner, especially for
multilevel generzlized linear models.
Now go back to my two-level poisson model with cross-classified model.
I've been testing various different model specificatios for the
2008 Jun 05
1
warning message for lmer model with poisson family
Hello,
I'm trying to run an lmer model with family poisson but receive the
following
warning message:
model<-lmer(count~tem+dat+alt+year+tem:dat+tem:alt+tem:year+dat:alt+dat:year+alt:year+(1|id),family=poisson)
Error in objective(.par, ...) :
Leading minor of order 2 in downdated X'X is not positive definite
I'm using the newest version of R and recently installed the
2009 Nov 20
1
different results across versions for glmer/lmer with the quasi-poisson or quasi-binomial families: the lattest version might not be accurate...
Dear R-helpers,
this mail is intended to mention a rather trange result and generate potential useful comments on it. I am not aware of another posts on this issue ( RSiteSearch("quasipoisson lmer version dispersion")).
MUsing the exemple in the reference of the lmer function (in lme4 library) and turning it into a quasi-poisson or quasi-binomial analysis, we get different results,
2008 Oct 12
2
Overdispersion in the lmer models
Dear All,
I am working with linear mixed-effects models using the lme4 package in R. I created a model using the lmer function including some main effects, a three-way interaction and a random effect.
Because I work with a binomial and poisson distribution, I want to know whether there is overdispersion in my data or not. Does anybody know how I can retrieve this information from R?
Thank you
2007 Jan 23
0
New lmer: How to recode random effect ?
Dear all,
I ran the following model without any problem previously to the update of
lme4:
fm2<-lmer(data=NGud,family=poisson,
seed~hab*seedtray
+(1|site)+(1|site:hab))
I have 25 sites, 2 habitats ("hab") per site, 8 seedtrays per habitat (4 as
control, and 4 as treatment), and I'm interested in comparing the number of
seed in seedtrays as a function of the treatment and its
2011 Oct 25
1
Unlist alternatives?
dfhfsdhf at ghghgr.com
I ran a simple lme model:
modelrandom=lmer(y~ (1|Test) + (1|strain), data=tempsub)
Extracted the BLUPs:
blups=ranef(modelrandom)[1]
Even wrote myself a nice .csv file....:
write.csv(ranef(modelrandom)[1],paste(x,"BLUPs.CSV"))
This all works great. I end up with a .csv file with the names of my strains
in the first column and the BLUP in the second
2006 Mar 31
1
loglikelihood and lmer
Dear R users,
I am estimating Poisson mixed models using glmmPQL
(MASS) and lmer (lme4). We know that glmmPQL do not
provide the correct loglikelihood for such models (it
gives the loglike of a 'pseudo' or working linear
mixed model). I would like to know how the loglike is
calculated by lmer.
A minor question is: why do glmmPQL and lmer give
different degrees-of-freedom for the same