This is equivalent to stats::setNames()
, with more features and
stricter argument checking.
set_names(x, nm = x, ...)
Vector to name.
Vector of names, the same length as x
. If length 1,
nm
is recycled to the length of x
following the recycling
rules of the tidyverse..
You can specify names in the following ways:
If not supplied, x
will be named to as.character(x)
.
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.
Otherwise if ...
is supplied, x
is named to c(nm, ...)
.
If nm
is NULL
, the names are removed (if present).
set_names()
is stable and exported in purrr.
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
# If length 1, the second argument is recycled to the length of the first:
set_names(1:3, "foo")
#> foo foo foo
#> 1 2 3
set_names(list(), "")
#> named list()