That's a good example with a couple levels of nesting (similar to the examples in the other book), but they still only have one factor, 'Variety', nested in each block. Am I missing something? Should I make up a psuedofactor with four levels to code my two two-level factors?
On Thu, May 7, 2009 at 5:46 PM, Rubén Roa-Ureta <r...@udec.cl> wrote: > Joshua Stults wrote: >> >> Hi, >> >> I'm trying to figure out how to use lme() for analyzing a split-plot >> experiment. I've been looking at the examples from the 'R Book', >> those are nested but with only one factor at the whole-plot level, my >> test is 2^2 at the whole-plot level, with a single many level factor >> at the sub-plot level. My question is about properly specifying the >> random effects part of the model, >> >> lme( y ~ block + a*b*poly(c, n), random=~ ? ) >> >> Where 'a' and 'b' are my two level whole-plot factors and 'c' is the >> many level sub-plot factor. I'm not sure what to use to get the right >> error terms. Do I use two error terms: >> >> random = ~ 1 | block/a + 1 | block/b >> >> or one: >> >> random = ~ 1 | block/a*b >> >> or something else entirely? I haven't been able to find any relevant >> examples on Google. Thanks for any suggestions/pointers. >> >> > > Have you checked Pinheiro and Bates 2004 Mixed-effects models in S and > S-PLUS? They have a split-plot example starting on p. 45. > Rubén > -- Joshua Stults Website: http://j-stults.blogspot.com ______________________________________________ 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.
