Yes, that was what I was trying to do. Thank you very much for your reply! Olivier
-- View this message in context: http://r.789695.n4.nabble.com/Error-in-lmer-asMethod-object-matrix-is-not-symmetric-1-2-tp4645133p4645537.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.