NATALIA F TCHETCHERINA wrote: > Hello all, > I have problem with setting up random effects. > I have a model: > y=x1+x2+x1*x2+z1+z1*x2 > where x1, x2, x1*x2 are fixed effects > and z1, z1*x2 are random effects (crossed effects) > I use library(nlme) 'lme' function. > My question is: how I should set up random effects? > I did > lme(y~x1+x2+x1:x2, data=DATA, random=~z1+z1:x2, na.action='na.omit') > but it did not work. > > Sincerely, Natalia. > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
The answer will depend on the types of x1, x2 and z1 (i.e. whether each of them is numeric or a factor). Because you use x1:x2 I will assume that x1, x2 and z1 are all factors. In that case the formula term x1*x2 is equivalent to x1 + x2 + x1:x2 and you could write the call to lme as lme(y ~ x1*x2, data = DATA, random = ~1|z1/x1) For lmer from the lme4 package it would be lmer(y ~ x1*x2 + (1|z1) + (1|z1:x1), data = DATA) ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
