dplyr: Multiple join_by 's.

tidyverse
1

Hello,

I am using the join_by dplyr function many times using the same variables, say : by = join_by(x, y, z).

Is it possible to " pass " this character vector in a join_by to avoid repeating the variables.

vars <- c("x", "y", "z")

Thank you,

Fred.

2

You can do this with rlang, actually I think quite easily since you're using tidyverse functions. From the documentation on the rlang injection operator !!:

All data-masking verbs in the tidyverse support injection operators out of the box. With base functions, you need to use inject() to enable !! .

Maybe a workflow like this:

left <- tibble::tibble(
  id_1 = c("A", "B", "C"),
  id_2 = c("D", "D", "E"),
  left_val = c(1, 2, 3)
)

right <- tibble::tibble(
  id_1 = c("A", "B", "C"),
  id_2 = c("D", "E", "E"),
  right_val = c(4, 5, 6)
)

join_vars <- c("id_1", "id_2")

dplyr::left_join(
  left,
  right,
  dplyr::join_by(!!!join_vars)
)
#> # A tibble: 3 × 4
#>   id_1  id_2  left_val right_val
#>   <chr> <chr>    <dbl>     <dbl>
#> 1 A     D            1         4
#> 2 B     D            2        NA
#> 3 C     E            3         6

Created on 2024-09-27 with reprex v2.1.1.9000

2 Likes
3

Thank you, Eric for your solution to my problem.
I will have a deeper look at the rlang documentation.

Best,
Fred.