I want to compare two vectors elementwise to check whether an element in a certain position in the first vector is different from the element in the same position in the second vector.
The point is that I have NA values inside the vectors, and when doing the comparison for these values I get NA instead of TRUE or FALSE.
Reproducible example:
Here is what I get:
a<-c(1, NA, 2, 2, NA)
b<-c(1, 1, 1, NA, NA)
a!=b
[1] FALSE TRUE NA NA NA
Here is how I would like the != operator to work (treat NA values as if they were just another "level" of the variable):
a!=b
[1] FALSE TRUE TRUE TRUE FALSE
There's a possible solution at this link, but the guy is creating a function to perform the task. I was wondering if there's a more elegant way to do that.
Taking advantage of the fact that:
T & NA = NA
but
F & NA = F
and
F | NA = NA
but
T | NA = T
The following solution works, with carefully placed brackets:
(a != b | (is.na(a) & !is.na(b)) | (is.na(b) & !is.na(a))) & !(is.na(a) & is.na(b))
You could define:
`%!=na%` <- function(e1, e2) (e1 != e2 | (is.na(e1) & !is.na(e2)) | (is.na(e2) & !is.na(e1))) & !(is.na(e1) & is.na(e2))
and then use:
a %!=na% b