Displaying 20 results from an estimated 600 matches similar to: "Extracting Variance components"
2007 Nov 09
1
Confidence Intervals for Random Effect BLUP's
I want to compute confidence intervals for the random effect estimates
for each subject. From checking on postings, this is what I cobbled
together using Orthodont data.frame as an example. There was some
discussion of how to properly access lmer slots and bVar, but I'm not
sure I understood. Is the approach shown below correct?
Rick B.
# Orthodont is from nlme (can't have both nlme and
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$Subject
fm1.s0.s <-
2005 Jul 12
1
nlme plot
Hello,
I am running this script from Pinheiro & Bates book in R Version 2.1.1 (WinXP).
But, I can't plot Figure 2.3.
What's wrong?
TIA.
Rod.
---------------------------------------------------------
>library(nlme)
> names( Orthodont )
[1] "distance" "age" "Subject" "Sex"
> levels( Orthodont$Sex )
[1] "Male"
2006 Nov 28
2
Problem with pairs() in nlme
Dear r-helpers,
After successfully running
require(nlme)
vfr.lmL <- lmList(
estimate ~ (slant + respType + visField + hand)^2 | subject, vfr
)
pairs(vfr.lmL, id = 0.01, adj = -0.5) # Pinheiro & Bates (p. 141)
produces the following error:
Error in sprintf(gettext(fmt, domain = domain), ...) :
object "form" not found
Any guesses as to what I may have done wrong?
2005 Dec 22
2
bVar slot of lmer objects and standard errors
Hello,
I am looking for a way to obtain standard errors for emprirical Bayes estimates of a model fitted with lmer (like the ones plotted on page 14 of the document available at http://www.eric.ed.gov/ERICDocs/data/ericdocs2/content_storage_01/0000000b/80/2b/b3/94.pdf). Harold Doran mentioned (http://tolstoy.newcastle.edu.au/~rking/R/help/05/08/10638.html) that the posterior modes' variances
2007 Jun 25
1
degrees of freedom in lme
Dear all,
I am starting to use the lme package (and plan to teach a course based on it
next semester...). To understand what lme is doing precisely, I used balanced
datasets described in Pinheiro and Bates and tried to compare the lme outputs
to that of aov. Here is what I obtained:
> data(Machines)
> summary(aov(score~Machine+Error(Worker/Machine),data=Machines))
Error: Worker
2009 May 20
1
Extracting correlation in a nlme model
Hi R users:
Is there a function to obtain the correlation within groups
from this very simple lme model?
> modeloMx1
Linear mixed-effects model fit by REML
Data: barrag
Log-restricted-likelihood: -70.92739
Fixed: fza_tension ~ 1
(Intercept)
90.86667
Random effects:
Formula: ~1 | molde
(Intercept) Residual
StdDev: 2.610052 2.412176
Number of Observations: 30
Number
2005 Sep 14
1
Random effect model
Dear R-help group,
I would like to model directly following random effect model:
Y_ik = M_ik + E_ik where M_ik ~ N(Mew_k,tau_k^2)
E_ik ~ N(0,s_ik^2)
i = number of study
k = number of treatment
---------------------------------------------------------------------------
I have practiced using the command from 'Mixed -Effects models in S and
S-plus'
2008 Nov 14
1
aov help
Please pardon an extremely naive question. I see related earlier
posts, but no responses which answer my particular question. In
general, I'm very confused about how to do variance decomposition with
random and mixed effects. Pointers to good tutorials or texts would
be greatly appreciated.
To give a specific example, page 193 of V&R, 3d Edition, illustrates
using raov assuming pure
2003 Mar 30
1
simple test of lme, questions on DF corrections
I''m a physicist working on fusion energy and dabble in statistics
only occasionally, so please excuse gaps in my statistical
knowledge. I''d appreciate any help that a real statistics expert
could provide. Most people in my field do only very simple
statistics, and I am trying to extend some work on multivariate
linear regression to account for significant between-group
2012 Feb 02
0
glmer question
I would like to fit the following model:
logit(p_{ij}) = \mu + a_i + b_j
where a_i ~ N(0, \sigma_a^2) , b_j ~ N(0, \sigma_b^2) and \sigma_a
= \sigma_b.
Is it possible to fit a model with such a constraint on the variance
components in glmer?
--
View this message in context: http://r.789695.n4.nabble.com/glmer-question-tp4351829p4351829.html
Sent from the R help mailing list archive at
2004 Apr 05
3
2 lme questions
Greetings,
1) Is there a nice way of extracting the variance estimates from an lme fit? They don't seem to be part of the lme object.
2) In a series of simulations, I am finding that with ML fitting one of my random effect variances is sometimes being estimated as essentially zero with massive CI instead of the finite value it should have, whilst using REML I get the expected value. I guess
2008 Aug 29
3
extract variance components
HI,
I would like to extract the variance components estimation in lme function
like
a.fit<-lme(distance~age, data=aaa, random=~day/subject)
There should be three variances \sigma_day, \sigma_{day %in% subject } and
\sigma_e.
I can extract the \sigma_e using something like a.fit$var. However, I cannot
manage to extract the first two variance components. I can only see the
results in
2009 Feb 28
0
Implementation of quasi-bayesian maximum likelihood estimation for normal mixtures
Hi,
as you can see in the topic, I am trying to fit a normal mixture
distribution with the approach suggested by Hamilton (1991). Since I
couldn't find any existing packages including the quasi-bayesian mle, I
have to write my own function. Unfortunately, I have absolutely no
experience in doing this.
If you're not familiar with the QB-MLE, I attached the formula as pdf.
The idea
2010 Jul 27
4
Sweave and scan()
I am introducing the scan() function to my class. Consider the following
file (Scanexamp.Rnw )
\documentclass[12pt]{article}
\begin{document}
<<>>=
height = scan()
64 62 66 65 62
69 72 72 70
part = scan(what = character(0))
"Soprano" "Soprano" "Soprano"
"Alto" "Alto" "Tenor"
"Tenor" "Bass"
2006 Apr 14
5
vector-factor operation
I found myself wanting to average a vector [vec] within each level of a
factor [Fac], returning a vector of the same length as vec. After a
while I realised that
lm1 <- lm(vec ~ Fac)
fitted(lm1)
did what I want.
But there must be another way to do this, and it would be good to be
able to apply other functions than mean() in this way.
Cheers, Murray
--
Dr Murray Jorgensen
2006 Nov 13
2
A printing "macro"
I am exploring the result of clustering a large multivariate data set
into a number of groups, represented, say, by a factor G.
I wrote a function to see how categorical variables vary between groups:
> ddisp <- function(dvar) {
+ csqt <- chisq.test(G,dvar)
+ print(csqt$statistic)
+ print(csqt$observed)
+ print(round(csqt$expected))
+ round(csqt$residuals)
+ }
>
> x
2011 Jan 05
4
Converting Fortran or C++ etc to R
I'm going to try my hand at converting some Fortran programs to R. Does
anyone know of any good articles giving hints at such tasks? I will post
a selective summary of my gleanings.
Cheers, Murray
--
Dr Murray Jorgensen http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz
2008 Mar 02
2
Recommended Packages
Having just update to R 2.6.2 on my old Windows laptop I notice that the
number of packages is growing exponentially and my usual approach of
get-em-all may not be viable much longer. Has any thought been given to
dividing "contributed" binaries into a recommended set, perhaps a couple
of hundred, and the remained. That way one could install the recommended
ones routinely and add in
2006 Jul 21
0
[Fwd: Re: Parameterization puzzle]
Bother! This cold has made me accident-prone. I meant to hit Reply-all.
Clarification below.
-------- Original Message --------
Subject: Re: [R] Parameterization puzzle
Date: Fri, 21 Jul 2006 19:10:03 +1200
From: Murray Jorgensen <maj at waikato.ac.nz>
To: Prof Brian Ripley <ripley at stats.ox.ac.uk>
References: <44C063E5.3020703 at waikato.ac.nz>