Displaying 20 results from an estimated 2000 matches similar to: "Sparse Matrix"
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
NLME Covariates
Dear list
In HLM, one can specify a covariate at one of the "levels". For example, if the data structure are repeated observations nested within students nested within schools, school size might be a covariate that is used at level 3, but not at the other levels. In HLM this is rather easy to do.
However, how can one specify a covariate in R for only one of the levels? I have a
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)
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 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
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,
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.
------
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 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,
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
2003 Dec 16
0
error constraints in lme
Dear List:
I am trying to figure out how to incorporate measurement error in an longitudinal educational data set using lme to create a "true score" model. As a by-product of the procedures used to scale educational tests, one can obtain a person-specific measurement error associated with each score, or a conditional standard error. For example, a score of 200 would have measurement
2003 Sep 10
3
Off Topic: Good reference for sample size calculations
Hi All,
This is off topic, but we're drawing a blank here..
> In a presentation I'll be giving next week, I want to include a reference
> to a good general text on computing sample sizes for standard experiments.
> Can anyone recommend a good book to use for this purpose?
>
> Thanks,
>
> -Greg
LEGAL NOTICE\ Unless expressly stated otherwise, this
2003 Aug 13
4
Levene test of homogeneity of variance
Has the Levene test of homogeneity of variance been implemented in any
library in R?
Thanks,
Maurice Haynes
National Institute of Child Health and Human Development
Child and Family Research Section
6705 Rockledge Drive
Bethesda, MD 20892
Voice: 301-496-8180
Fax: 301-496-2766
E-Mail: mh192j at nih.gov
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
2003 Jul 21
5
how to test whether two slopes are sign. different?
Not really r-specific:
Z = (b1 - b2) / SQRT ( SEb1^2 + SEb2^2)
-------Original Message-------
From: Gijsbert Stoet <stoet at volition.wustl.edu>
Sent: 07/20/03 09:51 PM
To: r-help at stat.math.ethz.ch
Subject: [R] how to test whether two slopes are sign. different?
>
> Hi,
suppose I do want to test whether the slopes (e.g. determined with
lsfit) of two different population are
2003 Jul 10
0
FW: Maximum Likelihood Estimation and Optimisation
Have a look at ?optim. I don't think it has the BHHH algorithm as an
option, though.
===========================================
David Barron
Jesus College
University of Oxford
-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch]On Behalf Of Harold Doran
Sent: 10 July 2003 15:43
To: Fohr, Marc [AM]; R-help at stat.math.ethz.ch
2004 Mar 02
4
how to delete a matrix column
Hello,
I am new to R, How to delete a matrix column.
Thanks,
2003 Nov 13
3
conf int mixed effects
Hi,
I have a linear mixed-effects model object and want to extract the 95%
confidence intervals for the fixed and random effects, respectively. I
found the function intervals() for confidence intervals for the fixed
effects but no corresponding function for the random effects. Does it
exist or do I have to calculate the confidence intervals for the random
effects myself?
Greetings,
joerg
2005 Nov 11
2
Running 'rsync' as root misses files
Wayne,
Hello, I saw a post of yours out on samba.org and was wondering if
you might be able to shed a little light on a problem I'm having with
rsync. My rsync source files are all off of nfs mounts and the
destination directories are all nfs mounts. The owner and groups all end
up as nobody/nobody on the destination, despite being all sorts of
owners and groups on the source. Have you
2007 Apr 12
0
[LLVMdev] "Name that compiler"
On 4/12/07, Chris Lattner <sabre at nondot.org> wrote:
> Note that the name need not capture every aspect of the project. Just
> having a distinguished name with no specific connotation is probably good
> enough. 20 years ago, "google" and "yahoo" had very different meanings,
> and "mozilla" or "firefox" were pretty meaningless. Today,