[R] inequality with NA

Uwe Ligges ligges at statistik.uni-dortmund.de
Fri Sep 22 20:25:25 CEST 2006



Mag. Ferri Leberl wrote:
> Dear everybody!
> take a<-c(5,3,NA,6).
> 
> if(a[1]!=NA){b<-7}
> if(a[3]!=5){b<-7}
> if(a[3]!=NA){b<-7}
> if(a[3]==NA){b<-7}
> 
> will alltogeather return
> 
> Fehler in if (a[1] != NA) { : Fehlender Wert, wo TRUE/FALSE nötig ist
> 
> (or simularly). Somehow this is logical. But how else should I get out,
> whether a certain vector-component has an existing value?

see ?is.na

Hence:
   if(!is.na(a[1])) b <- 7

Uwe Ligges


> Thank you in advance!
> Yours,
> Mag. Ferri Leberl
> 
> ______________________________________________
> R-help at stat.math.ethz.ch 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.



More information about the R-help mailing list