As part of a larger function, I'm trying to extract unique, non-na values, so I can iterate over that list. In this function, users should be able to input any column name that exists in their dataframe.
In the past, when I've had to convert a user input into a string, x_character <- deparse(substitute(x)) has worked. However, now I get NULL as my output of the below function with the warning of 1: Unknown or uninitialised column: x.
Why is R not recognizing this x_character with the $ operator? It's worked in the past, so I'm not sure if I'm doing something wrong here.
#Sample data
library(dplyr)
my_data <- tibble(level = c(rep(c("1st", "2nd", NA, "3rd"), 4), NA, "2nd"),
id = c(1:17, 30),
score = c(81:97, 70))
And here's my code:
unique_without_na <- function(data, x) {
#Pulls out all rows with data in the cut_by argument; drops nas
x_character <- deparse(substitute(x))
print(x_character) #just a check
unique_x <- data$x_character[!is.na(data$x_character)] %>% unique()
unique_x
}
unique_without_na(my_data, level) #doesn't work; I've also tried "level" which also fails
unique_without_na(my_data, score) #also doesn't work
Put them in [[ instead of using $
unique_without_na <- function(data, x) {
#Pulls out all rows with data in the cut_by argument; drops nas
x_character <- deparse(substitute(x))
print(x_character) #just a check
unique_x <- data[[x_character]][!is.na(data[[x_character]])] %>% unique()
unique_x
}
unique_without_na(my_data, level)
#> [1] "level"
#> [1] "1st" "2nd" "3rd"
unique_without_na(my_data, score)
#> [1] "score"
#> [1] 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 70