similar to: Why can we combine design matrix and data-frame in R?

In our recent workshop on "Multilevel Modeling in R" we discussed handling data for multilevel modeling. An classic example of such data are test scores of students grouped into schools. We may wish to model the scores as functions of both student-level covariates and school-level covariates. Such data are often organized in a multi-table format with a separate table for each level of

Dear r-devel list members, Dirk Eddelbuettel brought the following problem to my attention. The code is abstracted from the appendix on mixed models from my R and S-PLUS Companion: > set.seed(12345) # for reproducibility > library(nlme) Loading required package: lattice > data(MathAchieve) > data(MathAchSchool) > attach(MathAchieve) > mses <- tapply(SES, School,

Dear R list members, I've turned up a strange discrepancy between results obtained from the lme function in the nlme package in R and results obtained with lme in S-PLUS. I'm using version 3.1-24 of nlme in R 1.4.1 under Windows 2000, and both S-PLUS 2000 and 6.0, again under Windows 2000. I've noticed discrepancies in a couple of instances. Here's one, using data from Bryk

Buenas noches, mi pregunta es tal vez sencilla. tengo esta libreria y estos datos library(nlme) data(MathAchieve) Infoest = MathAchieve en esta base quiero contar la cantidad de casos en la que la columna Sex, toma el valor Female, como puedo hacerle el filtro para ver solo los Females. y como puedo dentro del mismo conjunto de datos agregar la variable numerica que me cuente 1 si es Female y 0

I'm looking at Pinheiro & Bates "Mixed-Effects Models in S and S-PLUS" at the moment. Several datasets are used, one of which is called "PBIB" (a partially balanced incomplete block design). All the other datasets can be found somewhere or other in R. However, I cannot locate PBIB, and it does not seem to be mentioned in the latest edition of the R Full Reference

Hola Alexander. Para filtrar y obtener el subconjunto que necesitas, puedes hacerlo de la siguiente (una de ellas) manera: > Female <- subset(MathAchieve, subset=Sex=="Female") Crear una nueva variable recodificando "Sex" puedes hacerlo así: > Sex_recode <- Recode(MathAchieve$Sex, '"Female"=1; "Male"=0; ;', as.factor.result=TRUE) >

I am running the R-0.62.0 snapshot on a Linux system. This system has 128 Mb of real memory and almost never swaps. I am trying to use lme() on a very large example (7200 observations, 10 columns in the fixed effects, 2 columns in the random effects). We have the optimization nicely tuned so that goes relatively quickly. It seems, though, that all the data manipulation steps before the

Dear community, I'm trying to examine my grouped data following page 6 http://cran.r-project.org/doc/contrib/Fox-Companion/appendix-mixed-models.pdf. I'm trying lmList this way: model.list <- lmList(log(v.dep) ~ log(v2) +log(v4) + v3 | v5, subset = v6=0, data=data) and obtain this error message: In Ops.factor(v4, v4) : | not meaningful for factors My original model is

Dear R users, I'm estimating a two-level regresion model but having difficuly in finding a good R syntax example. Let me use an example to explain what I'm doing. The dependent variable is math score (mathscore). Predictors are at two levels. At the student level, they are household income (hinc) and IQ (IQ). At the school level, there is a dummy variable indicating if the school is a

Dear R users, I would like to aggregate a data frame using several functions at once (e.g., mean plus standard error). How can I make this work using aggregate()? The help file says scalar functions are needed; can anyone help? Below is the code for my "meanse" function which I??d like to use like this: aggregate(dataframe, list(factorA,factoB),meanse) Thanks for your help!

Hi, a new version of WineTools is released. Changes are: - DC++ included - DependencyWalker included - PostgreSQL ODBC driver - DBCrab with BDE 5.1.1 - BDE 5.1.1 English Update - IE6 starts without ICW now - Editing the config can now be aborted without deleting it - Lauge is working again (reinstall, please) - Legal notice and disclimer - Typograf in english also - Visual C++ run-time in