Set names of a vector

This is equivalent to stats::setNames(), with more features and stricter argument checking.

set_names(x, nm = x, ...)

Arguments

x

Vector to name.
nm, ...

Vector of names, the same length as x.

You can specify names in the following ways:

  • If you do nothing, x will be named with itself.

  • If x already has names, you can provide a function or formula to transform the existing names. In that case, ... is passed to the function.

  • If nm is NULL, the names are removed (if present).

  • In all other cases, nm and ... are coerced to character.

Life cycle

set_names() is stable and exported in purrr.

Examples

set_names(1:4, c("a", "b", "c", "d"))
#> a b c d 
#> 1 2 3 4 
set_names(1:4, letters[1:4])
#> a b c d 
#> 1 2 3 4 
set_names(1:4, "a", "b", "c", "d")
#> a b c d 
#> 1 2 3 4 

# If the second argument is ommitted a vector is named with itself
set_names(letters[1:5])
#>   a   b   c   d   e 
#> "a" "b" "c" "d" "e" 

# Alternatively you can supply a function
set_names(1:10, ~ letters[seq_along(.)])
#>  a  b  c  d  e  f  g  h  i  j 
#>  1  2  3  4  5  6  7  8  9 10 
set_names(head(mtcars), toupper)
#>                    MPG CYL DISP  HP DRAT   WT QSEC VS AM GEAR CARB
#> Mazda RX4         21.0   6  160 110 3.90 2.62 16.5  0  1    4    4
#> Mazda RX4 Wag     21.0   6  160 110 3.90 2.88 17.0  0  1    4    4
#> Datsun 710        22.8   4  108  93 3.85 2.32 18.6  1  1    4    1
#> Hornet 4 Drive    21.4   6  258 110 3.08 3.21 19.4  1  0    3    1
#> Hornet Sportabout 18.7   8  360 175 3.15 3.44 17.0  0  0    3    2
#> Valiant           18.1   6  225 105 2.76 3.46 20.2  1  0    3    1

# `...` is passed to the function:
set_names(head(mtcars), paste0, "_foo")
#>                   mpg_foo cyl_foo disp_foo hp_foo drat_foo wt_foo qsec_foo
#> Mazda RX4            21.0       6      160    110     3.90   2.62     16.5
#> Mazda RX4 Wag        21.0       6      160    110     3.90   2.88     17.0
#> Datsun 710           22.8       4      108     93     3.85   2.32     18.6
#> Hornet 4 Drive       21.4       6      258    110     3.08   3.21     19.4
#> Hornet Sportabout    18.7       8      360    175     3.15   3.44     17.0
#> Valiant              18.1       6      225    105     2.76   3.46     20.2
#>                   vs_foo am_foo gear_foo carb_foo
#> Mazda RX4              0      1        4        4
#> Mazda RX4 Wag          0      1        4        4
#> Datsun 710             1      1        4        1
#> Hornet 4 Drive         1      0        3        1
#> Hornet Sportabout      0      0        3        2
#> Valiant                1      0        3        1