[R] Why can't R understand if(num!=NA)?

[David Winsemius]

On May 3, 2013, at 8:24 AM, jpm miao 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?

Read the "manual":

  ?"NA"


-- 

David Winsemius
Alameda, CA, USA