num1<- c(0,NA,1,3) num1==NA #[1] NA NA NA NA num1!=NA #[1] NA NA NA NA is.na(num1) #[1] FALSE TRUE FALSE FALSE A.K.
----- Original Message ----- From: jpm miao <miao...@gmail.com> To: r-help <r-help@r-project.org> Cc: Sent: Friday, May 3, 2013 11:24 AM Subject: [R] Why can't R understand if(num!=NA)? 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. ______________________________________________ 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.
