similar to: Are you experienced in SAS ...

Good Day, Included below is some code to generate data and to fit a mixed effects model to this fake data. The code works as expected when I call the function "lme" in Splus but not in R. The error message from calling lme in R is: "Error in getGroups.data.frame(dataMix, groups) : Invalid formula for groups" I installed the nlme package for R around 20 August

Moi! I was helping to teach a course on mixed models this week, and we came across a problem with coding more than one random effect in lme when they aren't nested. As an example, suppose we have an experiment where we sample moths from several populations, and place the moths on different trees, and measure a trait (in this case survival of offspring, but that's less important). We

Hi al, I have a dataset (see attached), which basically involves 4 treatments for a chemotherapy drug. Samples were taken from 2 biopsy locations, and biopsy were taken at 2 time points. So each subject has 4 data points (from 2 biopsy locations and 2 time points). The objective is to study treatment difference.? I used lme to fit a mixed model that uses "biopsy.site nested within pid"

The source of the incompatibility: In S-PLUS 6.2: > methods("unique") splus splus menu splus "unique.data.frame" "unique.default" "unique.name" "unique.rowcol.names" In R-1.9.1: > methods("unique") [1] unique.array unique.data.frame unique.default unique.matrix

I have been using lme from nlme to do a 3-way anova with all the effects treated as random. I was wondering if someone could direct me to an example of how to do this using lmer from lme4. I have 3 main effects, tim, trt, ctr, and all the interaction effects tim*trt*ctr. The response variable is ge. Here is my lme code: dat <-

I've posted the following to R-help on May 15. It has reproducible R code for real data -- and a real (academic, i.e unpaid) consultion background. I'd be glad for some insight here, mainly not for myself. In the mean time, we've learned that it is to be expected for anova(*, "marginal") to be contrast dependent, but still are glad for advice if you have experience. Thank

My thanks to Drs. Armstrong, Bates, Harrell, Liaw, Lumley, Prager, Schwartz, and Mr. Wang for their replies. I have pasted my original message and their replies below. After viewing http://www.itl.nist.gov/div898/strd/ as suggested by Dr. Schwartz, it occurred to me that it might be educational to search for some data repositories on google. I was able to find some,though I'm sure many of

Dear R-help group, How can I define a lme with 3 factors(a,b,c), where c is nested in b, and a is crossed with b/c? I think that: lme(response ~ ..., data = Data, random = pdBlocked(list(pdIdent(~ a - 1), pdIdent(~ b - 1)))) is one part of the answer and: lme(response~..., data=Data, random=~1|b/c) is the other part of the answer but how can I combine them?? Could anybody please help

I am (desperately) trying to get used to using a Mac here at my new location. (Why *anyone* would ever use anything other than Linux, except under duress as I am, totally escapes me, but that's another story.) Fortunately much of the Mac OSX is actually Unix, so a civilized person can manage to carry on ... But there are some things. (Like this <expletive deleted> mailer ... But

I am one of only 5 or 6 people in my organization making the effort to include R/Splus as an analysis tool in everyday work - the rest of my colleagues use SAS exclusively. Today, one of them made the assertion that he believes the numerical algorithms in SAS are superior to those in Splus and R -- ie, optimization routines are faster in SAS, the SAS Institute has teams of excellent numerical

Hi, I have a data set on germination and plant growth with the following variables: dataset=fm mass (response) sub (fixed effect) moist (fixed effect) pop (fixed effect) mum (random effect nested within population) iheight (covariate) plot (random effect- whole plot factor for split-plot design). I want to see if moist or sub interacts with mum for any of the pops, but I am getting an error

Hi: I have a dataframe containing comma seperated group of words such as milk,bread bread,butter beer,diaper beer,diaper milk,bread beer,diaper I want to output the frequency of occurrence of comma separated words for each row and collapse duplicate rows, to make the output as shown in the following dataframe: milk,bread 2 bread,butter 1 beer,diaper 3 milk,bread 2 Thanks for help! deb

Hi, all, I have a question about random effects model. I am dealing with a three-factor experiment dataset. The response variable y is modeled against three factors: Samples, Operators, and Runs. The experimental design is as follow: 4 samples were randomly chosen from a large pool of test samples. Each of the 4 samples was analyzed by 4 operators, randomly selected from a group of

Hello all: I am interested in computing what the multilevel modeling literature calls a multiple membership model. More specifically, I am working with a data set involving clients and providers. The clients are the lower-level units who are nested within providers (higher-level). However, this is not nesting in the usual sense, as clients can belong to multple providers, which I understand

Hi there, I am reading the 2004 paper "Smoothing with mixed model software" in Journal of Statistical Software, by Ngo and Wand. I tried to run their first example in Section 2.1 using R but I had some problems. Here is the code: library(nlme) fossil <- read.table("fossil.dat",header=T) x <- fossil$age y <- 100000*fossil$strontium.ratio knots <-

Hi, I am wanting to look at frequent item sets using the arules package. I need to transform my data into a "transactions" object. The data I read in from a file has 2 columns, an ID and an item. How do I convert data like this into a transactions object? I've tried class? transactions but it only confuses me. My data is like this.... basketID item 1 bread 1 cheese 1 milk 2

I am doing an analysis and would like to use lme() and the multcomp package to do multiple comparisons. My design is a within subjects design with three crossed fixed factors (every participant sees every combination of three fixed factors A,B,C). Of course, I can use aov() to analyze this with an error term (leaving out the obvious bits): y ~ A*B*C+Error(Subject/(A*B*C)) I'd also like

Hi, folks, Please first look at the codes: plan_a=c('apple','orange','apple','apple','pear','bread') plan_b=c('bread','bread','orange','bread','bread','yogurt') value=1:6 data=data.frame(plan_a,plan_b,value) library(plyr) library(reshape) mm=melt(data, id=c('plan_a','plan_b'))

Try this data(Assay) as1 <- lme(logDens~sample*dilut, data=Assay, random=pdBlocked(list( pdIdent(~1), pdIdent(~sample-1), pdIdent(~dilut-1)))) update(as1,random=pdCompSymm(~sample-1)) update(as1,random=pdCompSymm(~sample-1)) update(as1,random=pdCompSymm(~sample-1)) update(as1,random=pdCompSymm(~sample-1)) I'm

Hello, I have used nlme to fit a model, the R syntax is like fmla0<-as.formula(paste("~",paste(colnames(ldata[,9:13]),collapse="+"),"-1")) > fmla1<-as.formula(paste("~",paste(colnames(ldata[,14:18]),collapse="+"),"-1")) >