grepal returns a vector of colors whose names match a regular expression (regex).
grepal(pattern, x = colors(), ignore_case = TRUE)
Arguments
| pattern | A regular expression (specified as a string/character object). |
|---|---|
| x | A vector of R color names or a data frame of named colors
(i.e., whose names can be searched).
Default: |
| ignore_case | Should the case of pattern be ignored
(passed to |
Details
By default, the base R vector of named colors (i.e., colors()) is searched
for names matching a pattern (which can be a simple string or regular expression).
If x (i.e., the object to be searched) is provided,
it is must be a vector of color names or a data frame of named color objects
(i.e., a color palette).
This function facilitates searching colors by name and
yields (a vector of) colors of similar color hue (provided
that the color's hue is expressed in a color's name).
Its name grepal is an abbreviation of grep and "pal".
See also
seepal to plot color palettes;
usecol to use a color palette;
defpal to define new color palettes;
shades_of to define shades of a given color;
pal_unikn for the default uni.kn color palette.
Other color functions:
newpal(),
seecol(),
shades_of(),
usecol()
Examples
grepal("cyan")#> [1] "cyan" "cyan1" "cyan2" "cyan3" "cyan4" #> [6] "darkcyan" "lightcyan" "lightcyan1" "lightcyan2" "lightcyan3" #> [11] "lightcyan4"# With regular expressions: some_grey <- grepal("gr(a|e)y") start_grey <- grepal("^gr(a|e)y") only_grey <- grepal("^gr(a|e)y$") length(some_grey)#> [1] 224#> [1] 2# With other color objects (df as x): grepal("blau", x = pal_unikn)#> seeblau5 seeblau4 seeblau3 seeblau2 seeblau1 #> 1 #008ECE #00A9E0 #59C7EB #A6E1F4 #CCEEF9grepal("SEE", x = pal_unikn_pref)#> Seeblau Seegruen #> Seeblau #59C7EB #0A9086olives <- grepal("olive") oranges <- grepal("orange") seecol(list(olives, oranges), pal_names = c("olives", "oranges"), title = "Comparing olives and oranges")
