These functions are selection helpers.
everything() selects all variable. It is also useful in
combination with other tidyselect operators.
last_col() selects the last variable.
everything(vars = NULL)last_col(offset = 0L, vars = NULL)
A character vector of variable names. If not supplied,
the variables are taken from the current selection context (as
established by functions like select() or pivot_longer()).
Set it to n to select the nth var from the end.
Selection helpers can be used in functions like dplyr::select()
or tidyr::pivot_longer(). Let's first attach the tidyverse:
library(tidyverse)# For better printing
iris <- as_tibble(iris)
mtcars <- as_tibble(mtcars)
Use everything() to select all variables:
iris %>% select(everything())
#> # A tibble: 150 x 5
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#> <dbl> <dbl> <dbl> <dbl> <fct>
#> 1 5.1 3.5 1.4 0.2 setosa
#> 2 4.9 3 1.4 0.2 setosa
#> 3 4.7 3.2 1.3 0.2 setosa
#> 4 4.6 3.1 1.5 0.2 setosa
#> # i 146 more rowsmtcars %>% pivot_longer(everything())
#> # A tibble: 352 x 2
#> name value
#> <chr> <dbl>
#> 1 mpg 21
#> 2 cyl 6
#> 3 disp 160
#> 4 hp 110
#> # i 348 more rows
Use last_col() to select the last variable:
iris %>% select(last_col())
#> # A tibble: 150 x 1
#> Species
#> <fct>
#> 1 setosa
#> 2 setosa
#> 3 setosa
#> 4 setosa
#> # i 146 more rowsmtcars %>% pivot_longer(last_col())
#> # A tibble: 32 x 12
#> mpg cyl disp hp drat wt qsec vs am gear name value
#> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <chr> <dbl>
#> 1 21 6 160 110 3.9 2.62 16.5 0 1 4 carb 4
#> 2 21 6 160 110 3.9 2.88 17.0 0 1 4 carb 4
#> 3 22.8 4 108 93 3.85 2.32 18.6 1 1 4 carb 1
#> 4 21.4 6 258 110 3.08 3.22 19.4 1 0 3 carb 1
#> # i 28 more rows
Supply an offset n to select a variable located n positions
from the end:
mtcars %>% select(1:last_col(5))
#> # A tibble: 32 x 6
#> mpg cyl disp hp drat wt
#> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 21 6 160 110 3.9 2.62
#> 2 21 6 160 110 3.9 2.88
#> 3 22.8 4 108 93 3.85 2.32
#> 4 21.4 6 258 110 3.08 3.22
#> # i 28 more rows
The selection language page, which includes links to other selection helpers.