Displaying 20 results from an estimated 2000 matches similar to: "plotting multilevel / lme lines"
2007 Apr 16
1
Modelling Heteroscedastic Multilevel Models
Dear ListeRs,
I am trying to fit a heteroscedastic multilevel model using lmer{lme4-
package). Take, for instance, the (fictive) model below.
lmer(test.result ~ homework + Sex -1 + (1 | School))
Suppose that I suspect the error terms in the predicted values to
differ between men and women (so, on the first level). In order to
model this, I want the 'Sex'-variable to be random on
2007 Jun 10
1
{nlme} Multilevel estimation heteroscedasticity
Dear All,
I'm trying to model heteroscedasticity using a multilevel model. To
do so, I make use of the nlme package and the weigths-parameter.
Let's say that I hypothesize that the exam score of students
(normexam) is influenced by their score on a standardized LR test
(standLRT). Students are of course nested in "schools". These
variables are contained in the
2006 Mar 29
1
lmer multilevel
My question relates to problems that I'm having matching lme and lmer
examples in P&B.
using Matix 0.995
In the Oxide example in p167-170 I can't get the level 2 coefficient
estimates to match
the fm1Oxide model in lme is
data(Oxide,package="nlme")
lme(Thickness~1,Oxide)
which I translate in Lmer syntax to
fm3Oxide<-lmer(Thickness~
2007 Jul 30
1
Extract random part of summary nlme
Dear helpers,
I'm estimating multilevel regression models, using the lme-function
from the nlme-package. Let's say that I estimated a model and stored
it inside the object named 'model'. The summary of that model is
shown below:
Using summary(model)$tTable , I receive the following output:
> summary(model)$tTable
Value Std.Error DF t-value
2008 Aug 05
2
Adding .PDF files to a package
Deal all,
new as I am to developing packages for R-Project, I apologize on
beforehand for questions that are too obvious. I am trying to 'add' a
PDF document containing some detailed information to a package.
The way I understand the Rexts.pdf document, I should add my .PDF
document to the /inst/doc/ folder, and links to the files should be
build automatically. However, after
2007 Dec 07
2
Same regression per sub-group: apply?
Dear helpers,
I've come up with what is probably a simple problem, but I cannot
find the solution. I have a data-set containing survey-data from
several countries. What I want to do is to perform some regression
analyses, for each country separately. The question is, how to do
this nicely (thus without repeating the same syntax with another
`subset' argument).
I thought of the
2006 Aug 26
2
Importing data from clipboard on Mac OSX
Dear R users,
I am trying to get data from the clipboard into R on MacOSX. I tried
the following, but got an error message:
read.delim("clipboard")
Error in file(file, "r") : unable to open connection
In addition: Warning message:
unable to contact X11 display
Obviously, I'm not running R using X11. I'm wondering, can I import
data from the clipboard on MacosX?
2007 Jul 31
1
Extracting random parameters from summary lme and lmer
LS,
I'm estimating multilevel regression models, using the lme-function
from the nlme-package. Let's say that I estimated a model and stored
it inside the object named 'model'. The summary of that model is
shown below:
Using summary(model)$tTable , I receive the following output:
> summary(model)$tTable
Value Std.Error DF t-value
2006 Sep 26
2
Statistical data and Map-package
Dear helpeRs,
I'm working with the map-package and came upon a problem which I
couldn't solve. I hope onee of you can. If not, this can be seen as a
suggestion for new versions of the package.
I'm trying to create a map of some European countries, filled with
colors corresponding to some values. Let's say I have the following
countries and I assign the following colors
2006 May 19
1
Weird LM behaviour
Dear R users,
experimenting with the lm function in R, I've encountered some
behaviour I don't understand with my limited knowledge of regression.
I made a data-'set' of three measurements (see syntax below). Using
lm (linear model) to fit the regression-line, I expected to find an
intercept of 2.0 and a slope of 0, but in fact the slope is slightly
below zero. Amazed by
2015 Feb 15
2
Imports problem
I'm testing out a new version of coxme and R CMD check fails with "could not find function
ranef" (or random.effects or fixef, or anything from nlme). The NAMESPACE file has the
line below
importFrom(nlme, ranef, random.effects, fixef, fixed.effects, VarCorr)
and nlme is declared in the DESCRIPTION file as an import. I feel that I must be staring
at some obvious (but
2007 Oct 15
2
coef se in lme
Hi all!
How is it possible to estimate standard errors for coef obtained from lme?
Is there sth like se.coef() for lmer or what is the anaytical solution?
Thank you!
2010 Mar 05
2
Defining a method in two packages
The coxme package has a ranef() method, as does lme4. I'm having
trouble getting them to play together, as shown below. (The particular
model in the example isn't defensible, but uses a standard data set.)
The problem is that most of the time only one of lme4 or coxme will be
loaded, so each needs to define the basic ranef function as well as a
method for it. But when loaded together
2006 Mar 29
1
Lmer BLUPS: was(lmer multilevel)
Paul:
I may have found the issue (which is similar to your conclusion). I
checked using egsingle in the mlmRev package as these individuals are
strictly nested in this case:
library(mlmRev)
library(nlme)
fm1 <- lme(math ~ year, random=~1|schoolid/childid, egsingle)
fm2 <- lmer(math ~ year +(1|schoolid:childid) + (1|schoolid), egsingle)
Checking the summary of both models, the output is
2007 Aug 13
0
R^2 for multilevel models
Hi there,
In multiple regression one way to view R^2 is as (the square of) the
correlation between original y's and the estimated y's.
Suppose you fit a multilevel model with random intercept for each
cluster. Would it be valid to compute an R^2 by using fixed effects
plus the group intercepts to reduce the residuals?
I suspect this has been done and, given its absence from the lmer
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
2010 Jan 11
2
warning inside loop
Hi,
I'm running some data simulations using (mixed effects)* regression models
that show difficulty to converge. Therefore, I seek a way of capturing
warnings (of false convergence) inside a loop.
Inside that loop, I modify data and estimate a model. I do so many times
with slightly different modifications of the data. Next, I extract some of
the model parameters and store these in a matrix.
2013 Feb 04
10
duda con lmer. Añadir predictor a nivel de grupos
Hola a todos.
Estoy utilizando la función lmer del paquete lme4 para ajustar un modelo
mixto.
Tengo varias variables en mi data.frame, unas son a nivel individual y
otras a nivel de comarcas. Listo algunas.
ingre_6 : Ingresos (nivel individual)
iscs_a : un indicador sintético resumen de otras variables, calculado
mediante componentes principales.
sau_com : superficie agraria útil de cada una
2015 Feb 16
2
Imports problem
On 16/02/2015 8:20 AM, Therneau, Terry M., Ph.D. wrote:
>
>> > I'm testing out a new version of coxme and R CMD check fails with "could not find function
>> > ranef" (or random.effects or fixef, or anything from nlme). The NAMESPACE file has the
>> > line below
>>
>> > importFrom(nlme, ranef, random.effects, fixef,
2013 Apr 30
1
Mixed Modeling in lme4
Hi All,
I am trying to shift from running mixed models in SAS using PROC MIXED
to using lme4 package in R. In trying to match the coefficients of R
output to that of SAS output, I came across this problem.
The dataset I am using is this one:
http://support.sas.com/documentation/cdl/en/statug/63033/HTML/default/viewer.htm#statug_mixed_sect034.htm
If I run the following code:
proc mixed data=rc