So far nobody seems to have warned the OP about seeding.
Presumably Debbie wants 1000 different sets of samples, but as we all know there are ways to get the same sequence (initial seed) every time. If there's a starting seed for one of the "generate a single giant matrix" methods proposed, the whole matrix will be the same for a given seed. If rnorm is called 1000 times (hopefully w/ different random (oops) seeds), the entire set of samples will be different.
and so on. Carl ______________________________________________ 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.