r, does not equal, nas are not included

Question

I\'m trying to filter my data to leave out certain values. The problem is that I want to include the NAs. When I use the does not equal, \"!=\", operator, the NAs are also rem

Answer 1

We can include another condition in the filter function which will keep the NA values:

df %>%
   filter(a != "B" | is.na(a))

#      a
# 1    A
# 2    C
# 3 <NA>
# 4    C
# 5    A
# 6 <NA>
# 7    A

From ?NA

Logical computations treat NA as a missing `TRUE/FALSE value...

There's more to the explanation, but you can consult the help file.

Answer 2

NA is never equal to anything.

NA == NA # NA, not TRUE

@bouncyball's would be the recommended solution, if you want to check if two values or variables are really the same you can use identical :

df %>% filter(!sapply(a, identical, "B"))

or using library purrr

df %>% filter(!map_lgl(a, identical, "B"))