How can I negate a logical value in a base R pipeline?

Question

Running

TRUE |> `!`() 

Results in:

Error in !NULL : function '!' not supported in RHS call of a pipe (<input>:1:9) 

When using magrittr, there is a not() alias, but this does not work for base R. See: Negation `!` in a dplyr pipeline `%>%`

Answer 1

Simply adding brackets:

TRUE |> (`!`)() #[1] FALSE 

Answer 2

Negate()

One base R approach is to Negate() the identity() function:

TRUE |> Negate(identity)() # [1] FALSE 

This is parsed as Negate(identity)(TRUE), i.e. !TRUE.

isFALSE()

Alternatively, you can use isFALSE(), though this is limited to vectors of length one:

TRUE |> isFALSE() # [1] FALSE 

If you have a longer logical vector, v, you can *apply() this function. It's important to be aware that this is stricter than Negate(), both in terms of how it handles NA and how it treats other truthy/falsy values:

# NA values v <- c(TRUE, NA, FALSE) v |> Negate(identity)() # [1] FALSE NA TRUE v |> sapply(isFALSE) # [1] FALSE FALSE TRUE # Other falsy values e.g. 0 handled differently 0 |> Negate(identity)() # [1] TRUE 0 |> isFALSE() # [1] FALSE 

This is explicit, but whether its treatment of NA is desired will depend on your goal.

xor()

Finally, if you want to be perhaps a little too clever about it, you can use xor(), taking advantage of the fact that xor(x, TRUE) is equivalent to !x, because:

x	y	xor(x, y)
FALSE	TRUE	TRUE
TRUE	TRUE	FALSE

v <- c(TRUE, NA, FALSE) v |> xor(TRUE) # [1] FALSE NA TRUE identical(v |> xor(TRUE), !v) # [1] TRUE 

Answer 3

Why not define not() yourself?

not <- function(x) !x TRUE |> not() 

Answer 4

It's

> TRUE |> base::`!`() [1] FALSE 

Answer 5

With the native base R pipe operator you can do

TRUE |> { \(.) !. }() # [1] FALSE 

If this is useful depends on the task.