I didn't follow your question completely. But do a search for intraclass correlation with nlme or lmer and see if those results relate to the question you are asking. If so, I would suggest following up on the mixed model list. I know you wanted to avoid mixed models, but if I have understood your question, that is the way to use all of your data to estimate the parameters you seek.
On Thu, Feb 25, 2010 at 10:57 AM, Tal Galili <tal.gal...@gmail.com> wrote: > Hello dear R help group, > > I have the following setup to analyse: > We have about 150 subjects, and for each subject we performed a pair of > tests (under different conditions) 18 times. > The 18 different conditions of the test are complementary, in such a way so > that if we where to average over the tests (for each subject), we would get > no correlation between the tests (between subjects). > What we wish to know is the correlation (and P value) between the tests, in > within subjects, but over all the subjects. > > The way I did this by now was to perform the correlation for each subject, > and then look at the distribution of the correlations received so to see if > it's mean is different then 0. > But I suspect there might be a better way for answering the same question > (someone said to me something about "geographical correlation", but a > shallow search didn't help). > > p.s: I understand there might be a place here to do some sort of mixed > model, but I would prefer to present a "correlation", and am not sure how to > extract such an output from a mixed model. > > Also, here is a short dummy code to give an idea of what I am talking about: > > attach(longley) > N <- length(Unemployed) > block <- c( > rep( "a", N), > rep( "b", N), > rep( "c", N) > ) > Unemployed.3 <- c(Unemployed + rnorm(1), > Unemployed + rnorm(1), > Unemployed + rnorm(1)) > > GNP.deflator.3 <- c(GNP.deflator + rnorm(1), > GNP.deflator + rnorm(1), > GNP.deflator + rnorm(1)) > > cor(Unemployed, GNP.deflator) > cor(Unemployed.3, GNP.deflator.3) > cor(Unemployed.3[block == "a"], GNP.deflator.3[block == "a"]) > cor(Unemployed.3[block == "b"], GNP.deflator.3[block == "b"]) > cor(Unemployed.3[block == "c"], GNP.deflator.3[block == "c"]) > > (I would like to somehow combine the last three correlations...) > > > > Any ideas will be welcomed. > > Best, > Tal > > > > > > > ----------------Contact > Details:------------------------------------------------------- > Contact me: tal.gal...@gmail.com | 972-52-7275845 > Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | > www.r-statistics.com (English) > ---------------------------------------------------------------------------------------------- > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.