Apply a self-made function with mutate across - r

Question

I have created a function and I want to create new variables according to the conditions of the self-made function but I get mistakes...
This is my function:
percentages <- function(x) {
mutate(x = case_when(
x < 25 ~ "Menos 25%",
x <50 ~ "Entre 30% 50%",
x <75 ~ "Entre 50% 75%",
x >= 75 ~ "Más 75%")
)
return(x)
}
When I apply this code:
transp6 <- transp_articles %>% mutate
(across(c(perc_index_info_inst_org:perc_index_art_10_portal), percentages))
I get this result:
Error: Problem with mutate() input ..1.
i ..1 = across(...).
x no applicable method for 'mutate' applied to an object of class "character"
Run rlang::last_error() to see where the error occurred.
When I apply this:
transp6 <- transp_articles %>%
mutate(across
(.cols = c(perc_index_info_inst_org:perc_index_art_10_portal),
.fns = percentages(c(perc_index_info_inst_org:perc_index_art_10_portal)),
.names = "{.col}_rank"))
I get this:
rror: Problem with mutate() input ..1.
i ..1 = across(...).
x no applicable method for 'mutate' applied to an object of class "character"
Run `rlang::last_error()` to see where the error occurred.
In addition: Warning messages:
1: Problem with `mutate()` input `..1`.
i `..1 = across(...)`.
i numerical expression has 1031 elements: only the first used
Error: Problem with `mutate()` input `..1`.
i `..1 = across(...)`.
x no applicable method for 'mutate' applied to an object of class "character"
Run `rlang::last_error()` to see where the error occurred.
Finally, I try to do it with an apply:
apply(transp_articles$perc_index_info_inst_org:transp_articles$perc_index_art_10_portal,
margin = 2, percentages)
And I get:
Error in match.fun(FUN) : argument "FUN" is missing, with no default

Answer 1

Your problem is that you're passing a mutate to a mutate; across takes functions like case_when that accepts a vector and returns a vector. Easiest like this:
library(dplyr)
transp6 <-
transp_articles |>
mutate(across(perc_index_info_inst_org:perc_index_art_10_portal,
~ case_when(
. < 25 ~ "Menos 25%",
. < 50 ~ "Entre 30% 50%",
. < 75 ~ "Entre 50% 75%",
. >= 75 ~ "Más 75%"
)))
Alternatively, define your function:
percentages <- function(x) {
case_when(
x < 25 ~ "Menos 25%",
x < 50 ~ "Entre 30% 50%",
x < 75 ~ "Entre 50% 75%",
x >= 75 ~ "Más 75%")
)
}
And then:
library(dplyr)
transp6 <-
transp_articles |>
mutate(across(.cols = perc_index_info_inst_org:perc_index_art_10_portal,
.fns = percentages,
.names = "{.col}_rank"))
Without reproducible data I cannot make you a working example.
Edit: Bug fix + add example with across with the names argument as OP.