Displaying 20 results from an estimated 10000 matches similar to: "Variance components from lm?"
2005 Jun 26
1
Components of variance
Could someone identify a function that I might use to perform a
components of variance analysis? In addition to the variance
attributable to each factor, I would also like to obtain the SE of the
variances.
Thank you,
John
John Sorkin M.D., Ph.D.
Chief, Biostatistics and Informatics
Baltimore VA Medical Center GRECC and
University of Maryland School of Medicine Claude Pepper OAIC
University of
2005 Oct 07
3
panel data unit root tests
Hi,
The question is as follows: has anyone coded panel data unit root tests
with R? Even the "first generation" tests (see e.g. Levin & Lin 1993;
Pesaran, & Smith & Im 1996; Maddala & Wu 1999) would be sufficient for my
needs. To my understanding, these are rather easy to code, but as I have
taken just my first steps in coding with R, existing code would save me
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
2005 Dec 16
3
partially linear models
Hey,
I am estiamting a partially linear model y=X\beta+f(\theta) where the f(\theta) is estiamted using wavelets.
Has anyone heard of methods to test if the betas are significant or to address model fit?
Thanks for any thoughts or comments.
Elizabeth Lawson
__________________________________________________
[[alternative HTML version deleted]]
2005 Oct 04
1
repeated measures with random effects
Dear all,
I'm interested in analysing a reapeated measure desing where plant
height (H) was measured 3 times (Time). The experimental design
include 2 fixed factor (say A and B) in which A is nested in B, and a
random factor (C, the plot), using the aov().
So my first idea would be something like:
aov(H ~ B * A %in% B * Time + Error(id) )
where id is the factor coded for the repeated
2005 Oct 18
1
predictive interval in nlme
Suppose I have the following data:
y x id
44 0 104
48 58 104
48 55 204
47 105 204
41 275 206
18 67 209
.......
I fit the model
>fit=lme(y~x+I(x^2),random=~1|id)
Now I want to make a prediction plot:
>time=seq(0,300,len=100)
>plot(predict(fit,data.frame(x=time),level=0))
Very fine. It gives me the prediction curve based on
the model. My further request is to make a confidence
bands
2005 Sep 26
2
quasi-random vector according to an independent graph
Dear R-users,
Is anyone aware of any function/package for generating a random vector from
a joint distribution defined by an independent graph? Or I have to work it
out myself?
Thanks.
Jinfang
------------------------------
Jinfang Wang, Associate Professor
Chiba University, Japan
2005 Oct 10
1
lmer / variance-covariance matrix random effects
Hello,
has someone written by chance a function to extract the
variance-covariance matrix from a lmer-object? I've noticed the VarCorr
function, but it gives unhandy output.
Regards,
Roel de Jong
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 Jun 08
2
nested mixed-effect model: variance components
Dear listers,
I am trying to assess variance components for a nested, mixed-effects
model. I think I got an answer that make sense from R, but I have a
warning message and I wanted to check that what I am looking at is
actually what I need:
my data are organized as transects within stations, stations within
habitats, habitats within lagoons.
lagoons: random, habitats: fixed
the question is:
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'
2005 Nov 17
1
anova.gls from nlme on multiple arguments within a function fails
Dear All --
I am trying to use within a little table producing code an anova
comparison of two gls fitted objects, contained in a list of such
object, obtained using nlme function gls.
The anova procedure fails to locate the second of the objects.
The following code, borrowed from the help page of anova.gls,
exemplifies:
--------------- start example code ---------------
library(nlme)
##
2005 Aug 24
1
Panel regression in R
I am currently trying to replicate the results I got
from RATS for a panel regression. The codes in RATS
looks like this:
* Final equation for Office Cap Rate Spread
* Regression, Panel Data
preg(effects=time, method=random) CapRate
# CapRate{1} RentCycle{1} VacancyChangeYTY
InflationYTY RealGDPyty
Just wonder what R package also allow me to have the
options like (effects=time, method=random).
2005 Aug 18
1
code a family of garch
Dear R-helpers,
I was wondering if anyone has or knows someone who might have an
implementation
of algorithm for estimating garcht-t, egarch and gjr models. I try to
use Fseries but I don't know how to code these models.
Thanks a million in advance,
Sincerely,
Nongluck
2005 Sep 27
1
Producing empirical bayes estimates in disease mapping for lognormal model
I'm trying to produce empirical bayes estimates based on the lognormal
model in disease mapping
Is there a way this can be done in R?
thanks
Oarabile
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
2005 Dec 27
2
glmmPQL and variance structure
Dear listers,
glmmPQL (package MASS) is given to work by repeated call to lme. In the
classical outputs glmmPQL the Variance Structure is given as " fixed
weights, Formula: ~invwt". The script shows that the function
varFixed() is used, though the place where 'invwt' is defined remains
unclear to me. I wonder if there is an easy way to specify another
variance
2005 Nov 01
1
coding nesting in data for nlme example of Wafer data set.
I am trying to understand the proper way to encode the nesting structure
for data in the context of nlme, in the specific case of individuals
nested within species for which each individual is unique. I have
searched through Pinheiro & Bates and also past postings, but without
success.
Take the Wafer data set which has 2 levels: Wafer (8 values) and Site
nested within Wafer (10 values for
2005 Oct 12
2
linear mixed effect model with ordered logit/probit link?
Hello,
I'm working on the multiple categorical data (5-points scale) using linear
mixed effect model and wondering if anyone knows about or works on the
linear mixed effect model with ordered logit or probit link.
I found that the "lmer" function in R is very flexible and supports
various models, but not ordered logit/probit models. I may conduct my
analysis by turning my DVs
2005 Aug 12
1
converting a t statistic to r2
HI
I wonder if anyone can help. I have a longitudinal sample of 100 subjects:
200 data points were acquired starting at different ages and at irregular
intervals (subjects have different numbers of repeated data points, so some
have only one data point). I have been examining the relationship over time
(it is quadratic) of continuous variables A on variable B. To model this I
have been using