Can someone help me see where I'm going wrong? I thought when using curly-curly braces in a piped function that you could call the variable without having to enclose it in "" (i.e. as a string). So where is my function going wrong:
library(tidyverse)
dat <- structure(list(id = 1:6,
var_1 = c("1,1,-11000", "1,1,1", "0,0,0", "1,1,0", "1,1,1", "1,1,1"),
var_2 = c("0,0,-13000", "0,0,0", "-13000,-13000,-13000", "6,4,-13000", "0,0,0", "0,0,0"),
var_3 = c("24,7,-13000", "0,0,0", "-13000,-13000,-13000", "0,0,-13000", "0,0,0", "0,0,0")),
row.names = 1:6, class = "data.frame")
# Separate to wide and convert to long in one step
split_to_long <- function(col){
i <- substr({{col}}, 5, 5)
temp <- dat |>
select("id", {{col}}) |>
separate_wider_delim({{col}}, ",", too_few = "align_start",
names = c(paste0({{col}},"_1"),
paste0({{col}},"_2"),
paste0({{col}},"_3"))) |>
pivot_longer(2:4,
names_to = "visit",
values_to = paste0("var_", i),
names_prefix = paste0("var_", i, "_"))
temp
}
# This works
split_to_long("var_1")
# But this doesn't
split_to_long(var_1)
This comes from another question I posted: How to replace this for loop with purrr::map
If you want both to work, you can make a few modifications to your code, using the substitute function. I also suggest including a data argument to your function.
split_to_long <- function(data, col){
col_i <- substitute(col)
i <- substr(col_i, 5, 5)
temp <- data |>
select(id, {{col}}) |>
separate_wider_delim({{col}}, ",", too_few = "align_start",
names = c(paste0(col_i,"_1"),
paste0(col_i,"_2"),
paste0(col_i,"_3"))) |>
pivot_longer(2:4,
names_to = "visit",
values_to = paste0("var_", i),
names_prefix = paste0("var_", i, "_"))
temp
}
res1 <- split_to_long(dat, "var_1")
res2 <- split_to_long(dat, var_1)
identical(res1, res2)
[1] TRUE