Displaying 20 results from an estimated 4000 matches similar to: "Extracting Variance Components"
2012 May 14
1
Extract Variance Components
Hi,
I'm still having problems putting the variance components of my model in to
a data frame, it is a continuation of this discussion,
http://r.789695.n4.nabble.com/ANOVA-problem-td4609062.html, but now focussed
on the problem of extracting variance components. I have got my mixed
effects model now
/narrow$line<-as.factor(narrow$line)
rg.lmer <- lapply(split(narrow,
2006 Apr 25
5
Heteroskedasticity in Tobit models
Hello,
I've had no luck finding an R package that has the ability to estimate a
Tobit model allowing for heteroskedasticity (multiplicative, for example).
Am I missing something in survReg? Is there another package that I'm
unaware of? Is there an add-on package that will test for
heteroskedasticity?
Thanks for your help.
Cheers,
Alan Spearot
--
Alan Spearot
Department of Economics
2005 Apr 16
1
help on extract variance components from the fitted model by lm
Hey, all: Do we have a convenient command(s) to extract the variance
components from a fitted model by lm (actually it's a nexted model)?
e.g.: using the following codes we could get MSA,MSB(A) and MSE. How
to get the variance component estimates by command in R rather than
calculations by hand?
A<-as.vector(rep(c(rep(1,5), rep(2,5), rep(3,5), rep(4,5), rep(5,5)),2))
2006 Dec 13
1
Obtaining Estimates of the Random Effects Parameters
I'm running simulation using lme and sometimes the estimated
variance-covariance matrix is not positive definite so that the
intervals function won't work for the random effect coefficients. I've
tried varcomp from the ape package but this does not return all the
coefficients. How can I extract the random effect coefficients without
using intervals?
Rick B.
2006 Aug 15
3
merge 2 data frame based on more than 2 variables
Dear Lister,
I understand merge() can be used to join 2 data frames based on 1 variable.
But how about merge based on more than 2 variables?
Thank you so much!
--
WenSui Liu
(http://spaces.msn.com/statcompute/blog)
Senior Decision Support Analyst
Health Policy and Clinical Effectiveness
Cincinnati Children Hospital Medical Center
[[alternative HTML version deleted]]
2006 Feb 20
1
Extracting variance components from lmer
Hi All.
I need a bit of help extracting the residual error variance from the VarCorr
structure from lmer.
#Here's a 2-way random effects model
lmer.1 <- lmer(rating ~ (1|person)+(1|rater), data = dat)
#Get the structure
vc.fit <- VarCorr(lmer.1)
#results in.....
$person
1 x 1 Matrix of class "dpoMatrix"
(Intercept)
(Intercept) 0.7755392
$rater
1 x 1 Matrix
2005 Jun 24
1
lme4 extracting individual variance components
Hi,
For further calculations I need to extract indivdual Variances of
different random effects from a fitted model.
I found out how to extract the correlations
(VarCorr(m1)@reSumry$group1) but I was not able to find a way to
extract the other components individually.
To extract the Residuals I tried: (ranef(m1)@ stdErr) which
unfortunately did not work.
Thank you very much for your help!
2001 Nov 14
2
lme: how to extract the variance components?
Dear all,
Here is the question:
For example, using the "petrol" data offered with R.
pet3.lme<-lme(Y~SG+VP+V10+EP,random=~1|No,data=petrol)
pet3.lme$sigma gives the residual StdDev.
But I can't figure out how to extract the "(intercept) StdDev",
although it is in the print out if I do "summary(pet3.lme)".
In
2003 Dec 02
1
question regarding variance components
I am using a two-factor ANOVA model with random factor effects including
the interaction, i.e. the factors are crossed. I would like to be able to
generate all four variance components along with approximate confidence
intervals using the NLME package. However, I do not know how to specify
the random option because of two problems. First, I do not know how to
enter the interaction term into the
2006 Sep 04
1
Problem with Variance Components (and general glmm confusion)
Dear list,
I am having some problems with extracting Variance Components from a random-effects model:
I am running a simple random-effects model using lme:
model<-lme(y~1,random=~1|groupA/groupB)
which returns the output for the StdDev of the Random effects, and model AIC etc as expected.
Until yesterday I was using R v. 2.0, and had no problem in calling the variance components of the
2018 Jan 22
1
what does the within component of varcomp (ape library) output indicate?
I am trying to use varcomp to obtain the variance partitioning across
different nested levels of random effects (say x,y and z). I get the
three variance components (for each of my along with an additional one
called 'within' from varcomp output. I am using the 'scale total
variance to 1' option and though the within component is small, it
does form a part of what explains the
2008 Aug 29
3
extract variance components
HI,
I would like to extract the variance components estimation in lme function
like
a.fit<-lme(distance~age, data=aaa, random=~day/subject)
There should be three variances \sigma_day, \sigma_{day %in% subject } and
\sigma_e.
I can extract the \sigma_e using something like a.fit$var. However, I cannot
manage to extract the first two variance components. I can only see the
results in
2006 Jun 05
1
Extracting Variance components
I can ask my question using and example from Chapter 1 of Pinheiro & Bates.
> # 1.4 An Analysis of Covariance Model
>
> OrthoFem <- Orthodont[ Orthodont$Sex == "Female", ]
> fm1OrthF <-
+ lme( distance ~ age, data = OrthoFem, random = ~ 1 | Subject )
> summary( fm1OrthF )
Linear mixed-effects model fit by REML
Data: OrthoFem
AIC BIC
2003 May 23
1
variance components
Dear All,
I need to calculate the variance components in a mixed effect model (one
fixed and one random effect) with REML (maximizing the proportion of
the likelihood that does not depend on the fixed effects). In S+ there is
the varcomp function, but I would like to do it in R. Is there a way to do
that?
Thanks!
Katalin
___
Katalin Csillery
Division of Biological Sciences
University of
2006 Nov 28
3
comments in scan
I had a question about scan in R. For better code readability, I
would like to have lines in the block of data to be scanned that are
commented - not just lines that have a comment at the end. For example
#age, weight, height
33,128,65
34,56,155
instead of having to do something like
33,128,65 #age, weight, height
34,56,155
Is this at all possible?
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
2011 Mar 01
1
Components of variance with lme
R 2.10
Windows Vista
Is it possible to run a variance-components analysis using lme? I looked at Pinheiro and Bates' book and don't see code that will perform these analyses. If the analyses can not be done using lme, what package might I try?
Thanks,
John
John David Sorkin M.D., Ph.D.
Chief, Biostatistics and Informatics
University of Maryland School of Medicine Division of Gerontology
2012 Jan 30
1
Linear Mixed Model set-up
Hello,
I have some data covering contaminant concentrations in fish over a time
period of ~35 years. Each year, multiple samples of fish were taken (with
varying sample sizes each year). Ultimately, I want an estimation of the
variance between years, and the variance within years + random effects. I
used a linear mixed model to estimate these variances, but after reading a
number of different
2006 Aug 25
2
R in Nature
Hi all,
We've just had a paper accepted for publication in Nature. We used R for
95% of our analyses (one of my co-authors sneaked in some GenStat when I
wasn't looking.). The preprint is available from the Nature web site, in
the open peer-review trial section. I searched Nature for previous
references to "R Development Core Team", and I received no hits. So I
tentatively
2008 Feb 05
1
Extracting level-1 variance from lmer()
All,
How does one extract the level-1 variance from a model fit via lmer()?
In the code below the level-2 variance component may be obtained via
subscripting, but what about the level-1 variance, viz., the 3.215072 term?
(actually this term squared) Didn't see anything in the archives on this.
Cheers,
David
> fm <- lmer( dv ~ time.num*drug + (1 | Patient.new), data=dat.new )