[R] generic handling of NA and NaN and NULL

[Liaw, Andy]

The version I gave is obviously not vectorized (since your original version
seem to indicate that the argument won't have length > 1, otherwise the if()
won't really make sense).

Replacing is.null(n) with length(n)!=1 (or length(n)==0) should do the trick
(I hope!).

Andy

> -----Original Message-----
> From: Robin Hankin [mailto:r.hankin at auckland.ac.nz]
> Sent: Thursday, February 13, 2003 6:30 PM
> To: andy_liaw at merck.com
> Cc: r.hankin at auckland.ac.nz; r-help at stat.math.ethz.ch
> Subject: Re: [R] generic handling of NA and NaN and NULL
> 
> 
> 
> 
> Hello Andy
> 
> thanks for this; but
> 
> 
> R> x <- 1:10
> R> f
> function(n) {
>   if(is.null(n) || is.na(n) || abs(n) < pi) {
>     return(FALSE)
>   } else {
>     return(TRUE)
>   }
> }
> R> x <- 1:10
> R> f(x[x>11])
> Error in if (is.null(n) || is.na(n) || abs(n) < pi) { : 
> 	missing value where logical needed
> > 
> 
> 
> 
> 
> 
> 
> > 
> > Try:
> > 
> > f <- function(n) {
> >   if(is.null(n) || is.na(n) || abs(n) < pi) {
> >     return(FALSE)
> >   } else {
> >     return(TRUE)
> >   }
> > }
> > 
> > Note that the order of the conditions inside if() matters: 
> is.na(n) only
> > gets evaluated if is.null(n) is FALSE, and so on.
> > 
> > Andy
> > 
> 
> 
> -- 
> 
> Robin Hankin, Lecturer,
> School of Geography and Environmental Science
> Tamaki Campus
> Private Bag 92019 Auckland
> New Zealand
> 
> r.hankin at auckland.ac.nz
> tel 0064-9-373-7599 x6820; FAX 0064-9-373-7042
> 


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