On Thu, Aug 12, 2010 at 4:51 PM, Stephen Liu <sati...@yahoo.com> wrote: > Hi Barry, > > > Following 2 commands are useful to me; >> row.names(subset(file.info(list.files(getwd(),full.name=TRUE)),isdir)) > showing directories. > >> row.names(subset(file.info(list.files(getwd(),full.name=TRUE)),!isdir)) > showing files > > > What is "!" for? TIA
It means 'not'. So TRUE becomes FALSE and FALSE becomes TRUE. And NA stays NA. Use it when you need to invert logical values. Barry ______________________________________________ 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.
