Set names of a vector — set

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.

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 2.620 16.46  0  1    4    4
#> Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
#> Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
#> Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
#> Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
#> Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

# If the input vector is unnamed, it is first named after itself
# before the function is applied:
set_names(letters, toupper)
#>   A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T 
#> "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" 
#>   U   V   W   X   Y   Z 
#> "u" "v" "w" "x" "y" "z" 

# `...` 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  2.620    16.46
#> Mazda RX4 Wag        21.0       6      160    110     3.90  2.875    17.02
#> Datsun 710           22.8       4      108     93     3.85  2.320    18.61
#> Hornet 4 Drive       21.4       6      258    110     3.08  3.215    19.44
#> Hornet Sportabout    18.7       8      360    175     3.15  3.440    17.02
#> Valiant              18.1       6      225    105     2.76  3.460    20.22
#>                   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