Displaying 20 results from an estimated 20 matches for "mlmsoftrev".
2006 May 07
1
zero-inflated mixed models
Does anyone know of an existing R package or code to run a mixed Hurdle
model?
I found glmmADMB, but that seems to be ZIP.
Any recommendations?
Thanks,
Jeff
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2008 Jun 15
2
R vs SAS and HLM on multilevel analysis- basic question
Hi R users!
I am trying to learn some multilevel analysis, but unfortunately i am now very confused. The reason: http://www.ats.ucla.edu/stat/hlm/seminars/hlm_mlm/mlm_hlm_seminar.htm
http://www.ats.ucla.edu/stat/sas/seminars/sas_mlm/mlm_sas_seminar.htm
and
MlmSoftRev. pdf from mlmRev package.
>From what i see, the first two links seem to declare the level one variable as a random part (i don't know sas synthax, but i think i am right ) while Mr. Bates' pdf says that a grouping variable is the random part of the model, though both models, use rough...
2006 May 06
2
How to test for significance of random effects?
Dear list members,
I'm interested in showing that within-group statistical dependence is
negligible, so I can use ordinary linear models without including random
effects. However, I can find no mention of testing a model with vs.
without random effects in either Venable & Ripley (2002) or Pinheiro and
Bates (2000). Our in-house statisticians are not familiar with this,
either,
2006 May 03
1
qu: predict with lmer (lme4) or other ways to get classification accuracy
Hi,
I am using lmer (from the package lme4) to predict a binary response
variable (REL) from a bunch of fixed effects and two random effects
(Speaker_ID and NPhead_lemma):
fit <- lmer(REL ~
SPEAKER_GENDER +
log(SPEECHRATE) +
SQSPEECHRATE +
.....
+ (1|Speaker_ID) + (1|NPhead_lemma),
family="binomial",
data=data.lmer,
method="Laplace", model=T, x=T)
I
2006 Sep 05
1
help: advice on the structuring of ReML models for analysing growth curves
Hi R experts,
I am interested on the effects of two dietry compunds on the growth of
chicks. Rather than extracting linear growth functions for each chick and
using these in an analysis I thought using ReML might provide a neater and
better way of doing this. (I have read the pdf vignette("MlmSoftRev") and
"Fitting linear mixed models in R" by Douglas Bates but I am not entirely
sure that I have the right solution).
Basically I fed chicks in nest boxes over a period of time and weighed
them each time I fed them. I presume that "chick id" should be a random
factor and s...
2005 Sep 16
4
Possible bug in lmer nested analysis with factors
Hello,
Is this a bug in the lmer routine?
> library(lme4)
> ### test case based on rats data from Crawley
> a<-rnorm(36);b<-rep(1:3,each=12);c<-rep(1:2,each=6,3);d<-rep
(1:3,each=2,6)
>
> ### mixed model works when c & d are numeric, lmer assumes they
are factors
> m <- lmer(a ~ b + (1|c/d))
>
> ### but bails out when they are actually
2009 Sep 23
1
More naive questions: HLM6 comparisons? what is a "stack imbalance" in lmer? does lmer center variables?
...ting some big matrix
results, I suppose that could explain it.
2. What does "stack imbalance in .Call" mean in lmer?
Here's why I ask. Searching for comparisons of lmer and HLM, I went
to CRAN & I checked this document:
http://cran.r-project.org/web/packages/mlmRev/vignettes/MlmSoftRev.pdf
I *think* these things are automatically generated. The version
that's up there at this moment (mlmRev edition 0.99875-1) has pages
full of the error message:
stack imbalance in .Call,
Were those always there? I don't think so. What do they mean?
3. In the HLM6 output, there i...
2006 Jan 12
1
Multilevel models with mixed effects in R?
Group,
I am new to R. In my work as a program evaluator, I am regularly asked
to estimate effect sizes of prevention/intervention and educational
programs on various student outcomes (e.g. academic achievement). In
many cases, I have access to data over three or more time periods (e.g.
growth in proficiency test scores).
I usually have multiple independent and dependent variables in each
2006 Jul 25
1
how to fit with "lme" function
Hi everone,
I have a question on using lme on a mixed effects model.
The linear mixed model is in the form of:
y = bX +Zu + e
where "X" and "Z" are the matrices, "b" is the coefficient vector of fixed
effects, "u" is the coefficient vector of random effects, and e is an error
vector.
I would like to use "lme" function to fit the model and
2005 Sep 08
1
FW: Re: Doubt about nested aov output
Your response nicely clarifies a question that I've had for a long time,
but which I've dealt
with by giving each subject a unique label. Unless I'm missing something,
both techniques should
work as the toy example below gives exactly the same output in all 3 cases
below (forgetting
about the convergence problem). Would there be a reason to prefer
labeling the levels
one way or
2006 Jan 08
1
lmer with nested/nonnested groupings?
I'm trying to figure out how to use lmer to fit models with factors that
have some nesting and some non-nested groupings. For example, in this
paper:
http://www.stat.columbia.edu/~gelman/research/published/parkgelmanbafumi.pdf
we have a logistic regression of survey respondents' political
preferences (1=Republican, 0=Democrat), regressing on sex, ethnicity,
state (51 states within 5
2006 Oct 24
1
Variance Component/ICC Confidence Intervals via Bootstrap or Jackknife
I'm using the lme function in nmle to estimate the variance components
of a fully nested two-level model:
Y_ijk = mu + a_i + b_j(i) + e_k(j(i))
lme computes estimates of the variances for a, b, and e, call them v_a,
v_b, and v_e, and I can use the intervals function to get confidence
intervals. My understanding is that these intervals are probably not
that robust plus I need intervals on the
2006 Feb 27
1
question about lmer--different answers from different versions of R?
To whom it may concern:
I am using lmer for a statistical model that includes non-normally
distributed data and random effects. I used this same function in the
most recent version of R as of fall 2005, and have re-done some of the
same analyses using all of the same files, but with the newest version
of R (2.2.1). I get answers that are not exactly the same (although I
do get the same
2006 Oct 20
1
Translating lme code into lmer was: Mixed effect model in R
...SE, niterEM =
0)))
[1] 2.22 0.00 2.22 NA NA
On my Windows machine, the first model fit using lme took just over a
minute whereas the same model using lmer was estimated in 2.22 seconds.
There are other examples of how to use the lmer function in the mlmRev
package found using
vignette("MlmSoftRev")
This is anything but comprehenssive, but I hope others can chime in and
share their experiences, or correct any errors I may have made above.
Best,
Harold
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch] On...
2006 May 18
4
Nested design
Dear list members,
I'd like to perform a glm analysis with a hierarchically nested design. In
particular,
I have one fixed factor ("Land Use Classes") with three levels and a random
factor ("quadrat") nested within Land Use Classes with different levels per
classes (class artificial = 1 quadrat; class crops = 67 quadrats; and class
seminatural = 30 quadrats).
I have four
2006 Jul 15
3
names() function and lmer()
Hello All,
I would like to retrieve some of the results from the lmer(...)
function in library lme4. If I run a model, say
fm.1 <- lmer(y ~ 1 + (1 | x), data = dog)
and try names(fm.1), I get NULL. Is there anyway to retrieve the information?
Thanks
2006 Apr 22
1
Partially crossed and nested random factors in lme/lmer
Hi all,
I am not a very proficient R-user yet, so I hope I am not wasting people?s
time. I want to run a linear mixed model with 3 random factors (A, B, C)
where A and B are partially crossed and C is nested within B. I understand
that this is not easily possible using lme but it might be using lmer. I
encountered two problems when trying:
Firstly, I can enter two random factors in lmer but
2005 Aug 17
1
GLM/GAM and unobserved heterogeneity
Hello,
I'm interested in correcting for and measuring unobserved
heterogeneity ("missing variables") using R. In particular, I'm
searching for a simple way to measure the amount of unobserved
heterogeneity remaining in a series of increasingly complex models
(adding additional variables to each new model) on the same data.
I have a static database of 400,000 or
2006 Apr 13
3
Penalized Splines as BLUPs using lmer?
Dear R-list,
I?m trying to use the lmer of the lme4 package to fit a linear mixed model
of the form
Y = Xb + Zu + e
and I can?t figure out how to control the covariance structure of u. I want
u ~ N(0,sigma^2*I).
More precisely I?m trying to smooth a curve through data using the
"Penalized Splines as BLUPs" method as described in Ruppert, Wand &
Carroll (2003).
So I have Z = [Z1
2006 Aug 10
5
Variance Components in R
Hi,
I'm trying to fit a model using variance components in R, but if very
new on it, so I'm asking for your help.
I have imported the SPSS database onto R, but I don't know how to
convert the commands... the SPSS commands I'm trying to convert are:
VARCOMP
RATING BY CHAIN SECTOR RESP ASPECT ITEM
/RANDOM = CHAIN SECTOR RESP ASPECT ITEM
/METHOD = MINQUE (1)
/DESIGN