Displaying 20 results from an estimated 6000 matches similar to: "NLME Covariates"
2003 Jul 08
2
NLME Fitted Values
Dear List:
I am having difficulties with the fitted values at different levels of a multilevel model. My data set is a series of student test scores over time with a total of 7,280 observations, 1,720 students nested witin 60 schools. The data set is not balanced.
The model was fit using
eg.model.1<-lme(math~year, random=~year|schoolid/childid, data=single).
When I call the random
2003 Oct 06
2
Selecting a random sample for lmList()
Dear List:
I have a data set with over 7000 students with about 4 observations over time per student. I want to examine the within-group fits of a random sample of this group as it takes forever to compute and draw all 7000 regressions.
Here is the code I have used so far.
>group<-groupedData(math~year|childid, data=scores)
>group.list<-lmList(group)
2003 Apr 08
3
Multilevel Analyses in R
I am new to R and would like to get some practice analyzing multilevel data. I wonder if anyone can point me to a sample data set and command lines that I might replicate for a sample session. I would then compare my output with HLM output.
Any help is appreciated.
------
Harold C. Doran
Director of Research and Evaluation
New American Schools
675 N. Washington Street, Suite 220
Alexandria,
2004 Feb 18
2
Area between CDFs
Dear List:
I am trying to find the area between two ECDFs. I am examining the gap in performance between two groups, males and females on a student achievement test in math, which is a continuous metric.
I start by creating a subset of the dataframe
male<-subset(datafile, female="Male")
female<-subset(datafile, female="Female")
I then plot the two CDFs via
2003 Sep 29
3
Downloading LME4?
Dear R:
Am I having trouble downloading the LME4 library. I am using Windows and am using ver 1.7 I have tried the following:
1) Install package from CRAN, but LME4 is not listed
2) Downloaded LME4 from http://cran.us.r-project.org/, however, I cannot open the file when I try install from local drive. I get the following error:
Error in file(file, "r") : unable to open connection
2003 Jun 25
2
within group variance of the coeficients in LME
Dear listers,
I can't find the variance or se of the coefficients in a multilevel model
using lme.
I want to calculate a Chi square test statistics for the variability of the
coefficients across levels. I have a simple 2-level problem, where I want to
check weather a certain covariate varies across level 2 units. Pinheiro
Bates suggest just looking at the intervals or doing a rather
2006 Oct 20
1
Translating lme code into lmer was: Mixed effect model in R
This question comes up periodically, probably enough to give it a proper
thread and maybe point to this thread for reference (similar to the
'conservative anova' thread not too long ago).
Moving from lme syntax, which is the function found in the nlme package,
to lmer syntax (found in lme4) is not too difficult. It is probably
useful to first explain what the differences are between the
2004 Jul 02
1
Problem in lme4
Dear List:
I was able to run the following in nlme successfully, but the same model
and code (same dataset) failed to run in lme4 and gave me the error
message below. Any thoughts?
lme(math~year, data=egsingle, random=~year|schoolid/childid)
Error in lme(formula = math ~ year, data = egsingle, random =
structure(list( :
Unable to invert singular factor of downdated X'X
2003 May 30
1
Sparse Matrix
I am learning about sparse matrices and wonder if R can create them from a full matrix. Can anyone tell me how I might be able to accomplish this.
------
Harold C. Doran
Director of Research and Evaluation
New American Schools
675 N. Washington Street, Suite 220
Alexandria, Virginia 22314
703.647.1628
<http://www.edperform.net/>
[[alternate HTML version deleted]]
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
2003 Jun 23
1
R Commander
I am trying to import a file using R Commander. It was working a few days ago, but now I get the following message when I try to import from SPSS. Any thoughts?
Error in parse(file, n, text, prompt) : parse error
------
Harold C. Doran
Director of Research and Evaluation
New American Schools
675 N. Washington Street, Suite 220
Alexandria, Virginia 22314
703.647.1628
2006 Mar 23
1
NLME Covariates
HLM question?
Is there a minmum number of observations required for a category..I have
individusals in work teams.I have incomplete data for all the teams
..sometimes I only have data for one person in a team.I assume that HLM
can't work here! But what would be the mimimal.at the moment I have a
sample of about 240 in about 100 teams with teamsizes form 2 to 5.
Any advice?
Thanks
2003 Jul 22
1
Conditional Statements for Graphing
Dear List
I have math test scores for male and female students where gender is a dummy code (female =1). I also have a variety of other demographic variables.
However to begin, I want to create a very simple stripchart where female math scores are a blue circle and male scores are a red triangle.
I am having difficulty using conditional statements to accomplish this.
Thank you.
------
2005 Feb 28
1
Using mutiply imputed data in NLME
Dear All,
I am doing a growth modeling using NLME. I have three levels in my
data: observation, individual, household. About half of my total
sample have missing values in my household-level covariates. Under
this situation, the best way to go is probably to multiply impute the
data (for, say, 5 times), estimate the same model separately on each
model using LME function, and merge the results. My
2011 Jun 01
1
How to write random effect in MCMCglmm
Hi All,
The data set that I have is a cluster data, and I want to run a HLM mixed
model with multi-level response. Here is my data set:
response:
- Level (num: 1, 2, 3, 4, 5 - 5 levels)
Covariates:
- Type (Factor: A, B, C - 3 levels)
- yr (num: 2006, 2007, ...)
- Male (num: 0=not Male, 1=Male - 2 levels)
- Ethnicity (Factor: A, B, H, ..., - 7 levels)
- ELL (num: 0, 1, - 2
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
2003 Jun 23
2
read.spss
I have loaded the foreign package and am still having problems with an import. I get a message that reads, unable to open file. Whe I try different files I get the same message. Here is the code I used. Am I missing something?
I am using 1.7 and have also tried this in 1.6 with the same problem.
hsb<-read.spss("C:\HLM504_Student\Examples\AppendxA\HSB1.SAV", use.value.labels=TRUE,
2005 Dec 12
2
convergence error (lme) which depends on the version of nlme (?)
Dear list members,
the following hlm was constructed:
hlm <- groupedData(laut ~ design | grpzugeh, data = imp.not.I)
the grouped data object is located at and can be downloaded:
www.anicca-vijja.de/lg/hlm_example.Rdata
The following works:
library(nlme)
summary( fitlme <- lme(hlm) )
with output:
...
AIC BIC logLik
425.3768 465.6087 -197.6884
Random effects:
2003 Oct 02
0
Doubly Multivariate LME
Dear R:
I am trying to fit a doubly multivariate LME (DM) where I have two response variables measured on two occasions per person. Specifically, reading and math scores measured at the beginning and ending of a school year. The response variables have a correlation of r = .85.
The response variables in the data matrix are stacked in a vector with a dummy code flagging each outcome and with
2011 Feb 05
1
very basic HLM question
Hi everyone,
I need to get a between-component variance (e.g. random effects Anova),
but using lmer I don't get the same results (variance component) than
using random effects Anova. I am using a database of students, clustered
on schools (there is not the same number of students by school).
According to the ICC1 command, the interclass correlation is .44
> ICC1(anova1)
[1] 0.4414491