Is there a way to use a vector in coalesce function?-CodePudding

I have a number of variables that I want to coalesce together in R. I have extracted them into a vector to use them in the coalesce function. Typing each one of them in the function is a bit tedious. Is there a way to go about it?

library(dplyr)

set.seed(123)

df <- data.frame(
  var1 = sample(c(NA, 1, 3), 10, replace = T),
  var2 = sample(c(NA, 1, 3), 10, replace = T),
  var3 = sample(c(NA, 1, 3), 10, replace = T),
  var4 = sample(c(NA, 1, 3), 10, replace = T),
  age = floor(rnorm(10, 15, 2)),
  gender = factor(round(runif(10, 1, 2)),
              labels = c("Male", "Female"))
)

# Desired variables

myvars <- df %>% select(contains("var")) %>% names()


df_new <- df %>%
  mutate(finalvar = coalesce(myvars))

CodePudding user response：

Evaluate with !!! and unpack with rlang::syms:

df %>%
   mutate(finalvar = coalesce(!!! rlang::syms(myvars)))

Or directly attaching rlang:

library(rlang)
df %>%
   mutate(finalvar = coalesce(!!! syms(myvars)))

Both Output:

   var1 var2 var3 var4 age gender finalvar
1     3    1   NA   NA  14 Female        3
2     3    1   NA    3  17 Female        3
3     3   NA    3    3  14   Male        3
4     1    1    1   NA  12 Female        1
5     3    3    3    3  13 Female        3
6     1   NA    1    1  16 Female        1
7     1    3   NA   NA  14   Male        1
8     1    3    1    3  12   Male        1
9     3   NA    3   NA  13   Male        3
10   NA   NA    1   NA  14   Male        1

CodePudding user response：

Using invoke

library(dplyr)
library(purrr)
df %>% 
   mutate(finalvar = invoke(coalesce, across(all_of(myvars))))
   var1 var2 var3 var4 age gender finalvar
1     3    1   NA   NA  14 Female        3
2     3    1   NA    3  17 Female        3
3     3   NA    3    3  14   Male        3
4     1    1    1   NA  12 Female        1
5     3    3    3    3  13 Female        3
6     1   NA    1    1  16 Female        1
7     1    3   NA   NA  14   Male        1
8     1    3    1    3  12   Male        1
9     3   NA    3   NA  13   Male        3
10   NA   NA    1   NA  14   Male        1