Wacek Kusnierczyk wrote: > m = matrix(1:4, 2) > > apply(m, 1, cat, '\n') > # 1 2 > # 3 4 > # NULL > > why the null?
It comes from unlist()ing a list of NULLs, which in turn are the return values of cat(). It is arguably a design-buglet not to return list(NULL, NULL), but the internal logic is to unlist() unless the first element is.recursive (and NULL is not) or the return values have different length() (and all are zero). It _is_, however, in accordance with the documentation (see the Value: section): -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalga...@biostat.ku.dk) FAX: (+45) 35327907 ______________________________________________ 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.
