Why did you use the 'lower.tri' syntax? Does this work for you?
lme(Y~Random, data = DATA, random = list(Random = pdSymm(CovM,~Random))) Kevin On Wed, Jul 11, 2012 at 9:27 AM, Marcio <mrese...@ufl.edu> wrote: > Dear Simon, > Thanks for the quick reply. > Unfortunately I don't have access to Pinheiro and Bates. I tried googling > the pdSymm and lme but I still cannot get the syntax right. > > In my model, I only have 1 random factor with repetitions (groups) (e.g. 2 > records per each level) > I am pasting bellow a very small example (2 records and 2 levels) which > demonstrates the error I am having. > The syntax of lme is obviously wrong, and any help would be appreciated: > > Thanks > >> #Example >> CovM <- matrix(c(1,0.5,0.5,1),2) >> CovM > [,1] [,2] > [1,] 1.0 0.5 > [2,] 0.5 1.0 >> DATA <- data.frame(Y = c(rnorm(4)), Random = c(1,1,2,2)) >> DATA > Y Random > 1 0.24037680 1 > 2 0.03477704 1 > 3 -1.83389279 2 > 4 -0.84793117 2 >> lme(Y~Random, data = DATA, random = list(Random = pdSymm >> (CovM[lower.tri(CovM)],~Random))) > Error in `Names<-.pdMat`(`*tmp*`, value = c("(Intercept)", "Random")) : > Length of names should be 1 > > -- > View this message in context: > http://r.789695.n4.nabble.com/Mixed-Models-providing-a-correlation-structure-tp4635569p4636141.html > Sent from the R help mailing list archive at Nabble.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. -- Kevin Wright ______________________________________________ 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.