On 10/1/2006 12:29 PM, Alberto Vieira Ferreira Monteiro wrote: > Why this is not valid? > > test <- NULL > if (test) "test"
The test part of an if statement should evaluate to a length 1 logical or numeric value. NULL is length zero. The R Language Definition explains this (although it implies length > 1 is okay; in fact, that gives a warning). Duncan Murdoch ______________________________________________ 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 and provide commented, minimal, self-contained, reproducible code.
