thanks all; this makes sense now. For what it's worth, this came up in the context of mapply(...,SIMPLIFY=TRUE), which returned a matrix as requested, but an odd-looking one.
cheers Ben Bolker ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html