Difference between if_any(any_of(vars)) and if_any(all_of(vars))

Take the following MWE:

df <- data.frame(a=c(TRUE, TRUE, FALSE), b=c(FALSE, TRUE, FALSE))
myvars <- c("a","b")

The aim is to build a column c which is row-wise TRUE if one or both of a and b are TRUE.

It is required that the list of variables to use is held by vector character myvars.

With

df %>% mutate(c=if_any(myvars))

I get:

! Using an external vector in selections was deprecated in tidyselect 1.1.0.
ℹ Please use `all_of()` or `any_of()` instead.
  # Was:
  data %>% select(myvars)

  # Now:
  data %>% select(all_of(myvars))

See <https://tidyselect.r-lib.org/reference/faq-external-vector.html>.

Given that, I have to do:

df %>% mutate(c=if_any(any_of(myvars)))
df %>% mutate(c=if_any(all_of(myvars)))

But I don't understand the difference between those two.

if_any should imply any_of.

What is the difference between the two?

Answer

The difference is whether or not those columns are required to be in the data frame. all_of() will throw an error if you include any columns that aren't in the data frame. any_of() will happily work with whatever columns happen to be present in the data frame, ignoring any that aren't.

For code safety, you should use all_of() whenever you can, but sometimes, for example, you're writing scripts to work on similar inputs that have slightly different columns, and any_of() is very useful in this case.

To illustrate, let's add the non-existent "x" column to myvars:

## any_of still works
df %>% mutate(c=if_any(any_of(c(myvars, "x"))))
#       a     b     c
# 1  TRUE FALSE  TRUE
# 2  TRUE  TRUE  TRUE
# 3 FALSE FALSE FALSE


## all_of throws an error: ✖ Element `x` doesn't exist.
df %>% mutate(c=if_any(all_of(c(myvars, "x"))))
# Error in `mutate()`:
# ℹ In argument: `c = if_any(all_of(c(myvars, "x")))`.
# Caused by error in `if_any()`:
# ℹ In argument: `all_of(c(myvars, "x"))`.
# Caused by error in `all_of()`:
# ! Can't subset elements that don't exist.
# ✖ Element `x` doesn't exist.

This is explained at the shared help page accessible at ?any_of or ?all_of:

• all_of() is for strict selection. If any of the variables in the character vector is missing, an error is thrown.

• any_of() doesn't check for missing variables. It is especially useful with negative selections, when you would like to make sure a variable is removed.