Displaying 20 results from an estimated 3000 matches similar to: "lmer estimated scale"
2006 Mar 21
1
Scaling behavior ov bVar from lmer models
Hi all,
To follow up on an older thread, it was suggested that the following
would produce confidence intervals for the estimated BLUPs from a linear
mixed effect model:
OrthoFem<-Orthodont[Orthodont$Sex=="Female",]
fm1OrthF. <- lmer(distance~age+(age|Subject), data=OrthoFem)
fm1.s <- coef(fm1OrthF.)$Subject
fm1.s.var <- fm1OrthF. at bVar$Subject
fm1.s0.s <-
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 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
2013 Feb 05
1
lmer - BLUP prediction intervals
Dear all
I have a model that looks like this:
m1 <- lmer(Difference ~ 1+ (1|Examiner) + (1|Item), data=englisho.data)
I know it is not possible to estimate random effects but one can
obtain BLUPs of the conditional modes with
re1 <- ranef(m1, postVar=T)
And then dotplot(re1) for the examiner and item levels gives me a nice
prediction interval. But I would like to have the prediction
2008 Dec 04
2
Simulating underdispersed counts
Hello,
Anyone who knows a fast and accurate algorithm for generating draws from an underdispersed Poisson distribution. Or even better, if there is a package containing such an implementation.
Thanks
Rene
2006 Dec 31
7
zero random effect sizes with binomial lmer
I am fitting models to the responses to a questionnaire that has
seven yes/no questions (Item). For each combination of Subject and
Item, the variable Response is coded as 0 or 1.
I want to include random effects for both Subject and Item. While I
understand that the datasets are fairly small, and there are a lot of
invariant subjects, I do not understand something that is happening
2009 Jul 14
1
Simulation functions for underdispered Poisson and binomial distributions
Dear R users
I would like to simulate underdispersed Poisson and binomial
distributions somehow.
I know you can do this for overdispersed counterparts - using
rnbinom() for Poisson and rbetabinom() for binomial.
Could anyone share functions to do this? Or please share some tips for
modifying existing functions to achieve this.
Thank you very much for your help and time
Shinichi
2006 Sep 23
1
variance-covariance structure of random effects in lme
Dear R users,
I have a question about the patterned variance-covariance structure for the random effects in linear mixed effect model.
I am reading section 4.2.2 of "Mixed-Effects Models in S and S-Plus" by Jose Pinheiro and Douglas Bates.
There is an example of defining a compound symmetry variance-covariance structure for the random effects in a
split-plot experiment on varieties of
2006 Jan 25
1
About lmer output
Dear R users:
I am using lmer fo fit binomial data with a probit link function:
> fer_lmer_PQL<-lmer(fer ~ gae + ctipo + (1|perm) -1,
+ family = binomial(link="probit"),
+ method = 'PQL',
+ data = FERTILIDAD,
+ msVerbose= True)
The output look like this:
> fer_lmer_PQL
Generalized linear mixed model fit
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
2014 Feb 23
1
Random Count Generation with rnbinom
The documentation states :
An alternative parametrization (often used in ecology) is by the mean ?mu?, and ?size?, the dispersion parameter.
However, this fails :
> rnbinom(10, mu = 100, size = 0)
[1] NaN NaN NaN NaN NaN NaN NaN NaN NaN NaN
Warning message:
In rnbinom(10, mu = 100, size = 0) : NAs produced
For dispersion set to 0, it should work like drawing from a Poisson distribution.
2006 Dec 03
1
lmer and a response that is a proportion
Greetings all,
I am using lmer (lme4 package) to analyze data where the response is a
proportion (0 to 1). It appears to work, but I am wondering if the analysis
is treating the response appropriately - i.e. can lmer do this?
I have used both family=binomial and quasibinomial - is one more appropriate
when the response is a proportion? The coefficient estimates are identical,
but the standard
2006 Oct 05
1
mixed models: correlation between fixed and random effects??
Hello,
I built 4 mixed models using different data sets and standardized variables
as predictors.
In all the models each of the fixed effects has an associated random effect
(same predictor).
What I find is that fixed effects with larger (absolute) standardized
parameter estimates have also a higher estimate of the related random
effect. In other words, the higher the average of the absolute
2010 Oct 04
1
Ridge regression and mixed models
Dear R users,
An equivalence between linear mixed model formulation and penalized regression
models (including the ridge regression and penalized regression splines) has
proven to be very useful in many aspects. Examples include the use of the lme()
function in the library(nlme) to fit smooth models including the estimation of a
smoothing parameter using REML. My question concerns the use of
2012 Jan 09
0
what to do with underdispersed count data
Hi,
I have been trying to do a simple GLM with count data using a poisson
distribution. The results show evidence of underdispersion. I have only ever
encountered overdispersion. Am I still able to use family=quasipoisson to
correct for underdispersion?
Thank you,
Karla
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2012 Oct 25
2
Plot lmer model with Effects package
Hi everyone!
I have a simple model that i would like to plot with 95% CIs.
It is like follows:
m1<-lmer(Richness~Grazing+I(Grazing^2)+(1|Plot),family=poisson)
By using the effects package I get two plots, one for the linear term
and one for the squared term.
Q1: Can I get all in one? I.e. with one line for the whole model?
Q2: Can I also visualize the random effects?
I would be very happy for
2011 Jun 13
1
Somers Dyx
Hello R Community,
I'm continuing to work through logistic regression (thanks for all the help on score test) and have come up against a new opposition.
I'm trying to compute Somers Dyx as some suggest this is the preferred method to Somers Dxy (Demaris, 1992). I have searchered the [R] archieves to no avail for a function or code to compute Dyx (not Dxy). The overview of Hmisc has
2004 Apr 08
0
lme, mixed models, and nuisance parameters
I have the following dataset:
96 plots
12 varieties
2 time points
The experiment is arranged as follows:
A single plot has two varieties tested on it.
With respect to time points, plots come in 3 kinds:
(1) varietyA, timepoint#1 vs. variety B, timepoint#1
(2) varietyA timepoint #2 vs. varietyB timepoint #2
(3) varietyA timepoint #1 vs. variety A timepoint#2
- there are 36 of each kind
2009 Jul 15
1
negative Somers D from Design package
Dear R help
My problem is very similar to the analysis detailed here.
If we use the mayo dataset provided with the survivalROC package the estimate for Somer's Dxy is very negative -0.56.
The Nagelkerke R2 is positive though 0.32.
I know there is a difference between explained variation and predictive ability but I am surprised there is usch a difference given that even a non predictive model
2011 Jul 08
3
Efectos aleatorios, interaccions y SNK, LSD o Tukey
Queridos R-users:
Tengo una duda que hace mucho tiempo que estoy intentando resolver, os
explico a modo de ejemplo:
Tengo estos efectos: Año(5 niveles),Localidad (10 niveles) y genotipo
(3 niveles), año y localidad son aleatorios y genotipo es fijo (los he
escogido yo).
Me gustaría hacer obtener una tabla parecida a la Tabla Anova donde
aparezca cada factor y sus interacciones y