At a minimum, the first statement needs "==". Also, is.na() gives TRUE/FALSE. While a logical comparison to NA gives NA as a value.
Kevin On Fri, May 3, 2013 at 10:24 AM, jpm miao <miao...@gmail.com> wrote: > I have a program, when I write > > if(num!=NA) > > it yields an error message. > > However, if I write > > if(is.na(num)==FALSE) > > it works. > > Why doesn't the first statement work? > > Thanks, > > Miao > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Kevin Wright [[alternative HTML version deleted]] ______________________________________________ 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.