[R] "NA-friendly" operator

[Berend Hasselman]

On 30-10-2012, at 22:08, vincent guyader wrote:

> Hi everyone,
> 
> i'm looking for a "NA-friendly" operator
> 
> I explain :
> 
>        vec<-c(3,4,5,NA,1,NA,9,NA,1)
> 
>        vec[vec == 1]  # NA  1 NA NA  1
> 
> I dont want the NA's :
>        vec[vec == 1 & ! is.na(vec)]# 1  1
> is the same as
>        vec[vec %in% 1] # 1  1
> 
> %in% is NA-friendly :)
> 
> But if i want >2 without the NA's :
> 
>        vec[vec>2] #3  4  5 NA NA  9 NA
> 
> if i dont want the NA i have to do :
> 
>        vec[vec>2 & !is.na(vec)] #3  4  5  9
> 
> is there an opérator to directly do that?


You could define one

 "%>.nona%" <- function(x,y) x[x>y & !is.na(vec)]

and use

 vec %>.nona% 2

Use  ?`%in%` to see an example (in the Examples section)

Berend