I have some variables that should be coded 0-3 or NA but have been coded 1-4 with "." for NA. I want to recode them using mutate() and case_when() in a for loop but after running the loop my data don't change. No errors appear.
Before the transformation the data look like this:
tabyl(df$epds_1)
# df$epds_1 n
# . 6
# 1 472
# 2 93
# 3 45
# 4 23
# <NA> 10
I try to mutate ten variables using the following:
for (v in c("epds_1", "epds_2", "epds_3", "epds_4", "epds_5", "epds_6",
"epds_7", "epds_8", "epds_9","epds_10")) {
df <- df %>% mutate(`v` = case_when(`v` == "." ~ NA_real_,
`v` == "1" ~ 0,
`v` == "2" ~ 1,
`v` == "3" ~ 2,
`v` == "4" ~ 3))
}
Hoping for the following table to result (the count of 16 combining the top and bottom rows of the original table):
tabyl(df$epds_1)
# df$epds_1 n
# 0 472
# 1 93
# 2 45
# 3 23
# <NA> 16
You can use across() to apply a function to several variables.
vars <- c("epds_1", "epds_2", "epds_3", "epds_4", "epds_5", "epds_6",
"epds_7", "epds_8", "epds_9","epds_10")
df %>% mutate(across(all_of(vars), ~ case_when(.x == "." ~ NA_real_,
.x == "1" ~ 0,
.x == "2" ~ 1,
.x == "3" ~ 2,
.x == "4" ~ 3)))
As for why the loop isn't working.. to get it to work you would change your code to something like this.
for (v in c("epds_1", "epds_2", "epds_3", "epds_4", "epds_5", "epds_6",
"epds_7", "epds_8", "epds_9","epds_10")) {
df <- df %>% mutate(!!v := case_when(.data[[v]] == "." ~ NA_real_,
.data[[v]] == "1" ~ 0,
.data[[v]] == "2" ~ 1,
.data[[v]] == "3" ~ 2,
.data[[v]] == "4" ~ 3))
}
I would advise against this though and utilise dplyr's across as shown in my first example.