RE: [R] Repeated measures

If you fit the model as suggested below and store it in an object, say model.lme, then you can update the model as follows to include the continuous AR1 structure model2.lme-update(model.lme, correlation=corCAR1(form=~time|cow) ) To compare the two models, you might use the LRT as:

RE: [R] signifikanz?

You need cor.test(x,y). However, I do not think you mean significant at the .95 or .99 level, do you? -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Martin Klaffenboeck Sent: Tuesday, June 01, 2004 9:15 AM To: r-help Subject: [R] signifikanz? Hello,

[R] Merging nlme output

Dear list: I am trying to merge two files together from output I get based on the coef() command. Here is what I am running into. I have two simple linear mixed models mod1.lme-lme(math~year, data=sample, random=~year|childid/schoolid) mod2.lme-lme(math~year, data=sample,

[R] Help with Plotting Function

Dear List: I cannot seem to find a way to plot my data correctly. I have a small data frame with 6 total variables (x_1 ... x_6). I am trying to plot x_1 against x_2 and x_3. I have tried plot(x_2, x_1) #obviously works fine plot(x_3, x_1, add=TRUE) # Does not work. I keep getting error

[R] Fatal Error

Dear List: When trying to open 1.9.0 this morning, I have the following error: Fatal Error: Unable to restore saved data in .Rdata I am using Windows 2000. The program then quits. Do I need to reinstall? Harold C. Doran One Massachusetts Avenue, NW · Suite 700 Washington, DC 20001-1431

RE: [R] Fatal Error

Thank you. Locating and deleting the bad .Rdata file did the trick and I can now work in R. Thanks. -Original Message- From: Duncan Murdoch [mailto:[EMAIL PROTECTED] Sent: Monday, May 17, 2004 8:45 AM To: Harold Doran Cc: [EMAIL PROTECTED] Subject: Re: [R] Fatal Error On Mon, 17 May

RE: [R] 2 lme questions

There are two way to accomplish this in nlme. First try using the summary() command, which will produce all variance components and estimates for the fixed effects. Also, try the following to extract the point estimates and approximate CIs for the variance comonents. intervals(model.lme,

RE: [R] general mixed model statement

This would be accomplished via the nlme library for mixed linear models. See Pinhiero and Bates (2000) for all relevant documentation and data applications. Harold -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday, April 01, 2004 10:21 AM To: [EMAIL

RE: [R] rate of change

Type help(deriv). However, it may be easier to compute the derivative by hand for a simple expression. HCD -Original Message- From: Fred J. [mailto:[EMAIL PROTECTED] Sent: Monday, March 15, 2004 10:20 PM To: r help Subject: [R] rate of change Hello I am wondering, how do I find if R

RE: [R] still spss

It appears you may have left off the file extension, experiencial.sav -Original Message- From: Margarida Júlia Rodrigues Igreja [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 04, 1997 2:24 AM To: [EMAIL PROTECTED] Subject: [R] still spss hi again, i still cannot open the file in spss

RE: [R] how to delete a matrix column

You can use dataset$columnname=NULL HCD -- Harold C. Doran Director of Research and Evaluation New American Schools 675 N. Washington Street, Suite 220 Alexandria, Virginia 22314 703.647.1628 -Original Message- From: Aimin Yan [mailto:[EMAIL PROTECTED] Sent: Tuesday, March

RE: [R] Area between CDFs

Thanks. I have been able to create the following simple function to examine the vertical gap between two CDFs at a value along the x-axis that I specify. For example, I create the ECDFs: male.ecdf-ecdf(egmale$math) female.ecdf-ecdf(egfemale$math) I then define the following function:

[R] 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)

RE: [R] Sweave/LaTeX Problem with EPS PDF

Yes, they were lattice and your suggestion did the trick. Many thanks! -Original Message- From: Jason Turner [mailto:[EMAIL PROTECTED] Sent: Sun 12/21/2003 12:30 AM To: Harold Doran Cc: [EMAIL PROTECTED] Subject: Re: [R] Sweave/LaTeX

[R] Sweave/LaTeX Problem with EPS PDF

Dear List: I am unsure if my problem is with Sweave or LaTeX. Anyhow, I am using the MikTeX distribution and TexnicCenter. I can easily create Sweave files and all goes well until I try to incorporate graphics. I use the same code as found in the examples found in the users manual. In R,

[R] varFixed

Dear List: Earlier this week I posted a question and received no response, and I continue to struggle with my model. My original question is pasted below. I am using lme and want to fix the variance of the within group residual at 1 (e~n(0,1). I think the varFixed function should be used to

[R] 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

RE: [R] conf int mixed effects

I am very curious about this. If a particular growth model is specified to reflect repeated observations on individual i in unit j, such as: y_{tij} = [B_{00} + B_{01}*(TIME)]+[u_{00}+u_{01}*(TIME)+ e_{tij}] where Bs are the fixed effects and the u's are the random effects. The growth of

[R] 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.

[R] 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

[R] 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

RE: [R] Off Topic: Good reference for sample size calculations

Jacob Cohen's book Statistical Power Analysis for the Behavioral Sciences is one. -- 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 -Original

RE: [R] Levene test of homogeneity of variance

I believe it is in the Rcmdr package, which requires the car library to be loaded. You can also perform an ANOVA using the absolute value of the deviations from each respective group mean, which is what Levene's Test does. -- Harold C. Doran Director of Research and Evaluation New

[R] 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

RE: [R] how to test whether two slopes are sign. different?

Dear Stoet This can be handled well in using a mixed-effects model, library (nmle). You can use the lmList option to check whether the slopes differ across populations. -- Harold C. Doran Director of Research and Evaluation New American Schools 675 N. Washington Street, Suite 220

RE: [R] Maximum Likelihood Estimation and Optimisation

Well, lm() produces an OLS solution, which are also MLE solutions for the fixed effects. I think this is an easy way, although maybe not the best. BHHH is a numerical approximation that can be used when a closed form solution is not available. It is less sophisticated than Newton-Raphson. Is

RE: [R] NLME Fitted Values

[mailto:[EMAIL PROTECTED] Sent: Tue 7/8/2003 5:52 PM To: Harold Doran Cc: [EMAIL PROTECTED] Subject: Re: [R] NLME Fitted Values Harold Doran [EMAIL PROTECTED] writes: Dear List: I am having difficulties

RE: [R] within group variance of the coeficients in LME

-Original Message- From: Andrej Kveder [mailto:[EMAIL PROTECTED] Sent: Wednesday, July 02, 2003 5:41 AM To: Douglas Bates; J.R. Lockwood Cc: Harold Doran; R-Help Subject: RE: [R] within group variance of the coeficients in LME Firstly let me thank all for your answers and suggestions. I

RE: [R] within group variance of the coeficients in LME

lme does not produce standard errors for the variance components like HLM does. It does produce SEs for the fixed effects, however, along with t-statistics and p-values, just like HLM. Use the summary() command to see these. When you do this, you will get the AIC, BIC, and loglik values. Just

[R] 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

[R] 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

[R] 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