Thank you Michael. I think my initial problem may have been due to a 'clerical error' upriver, so I appreciate you taking the time to give me this help.
Unfortunately, my version of R does not contain simplify2array() and does not find it in help (?simplify2array) - which is strange because I just installed it recently. (RStudio on Linux64). I am hoping that it is fully updated soon. Thank you also for your reading suggestions - it had not even occurred to me to check S books as well as R. -- View this message in context: http://r.789695.n4.nabble.com/Covariance-Variance-Matrix-and-For-Loops-tp3859441p3860580.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.