| ac {unikn} | R Documentation |
Adjust color transparency
Description
ac adjusts the transparency of a color or color palette col
to an opacity level alpha (in [0, 1]).
Usage
ac(col, alpha = 0.5, use_names = TRUE)
Arguments
col |
A (required) color or color palette (as a vector). |
alpha |
A factor modifying the opacity alpha
(as |
use_names |
A logical value indicating whether color names should be adjusted
to include the values of |
Details
ac is mostly a wrapper for adjustcolor
of the grDevices package, but allows for more flexible
combinations of (multiple) col and alpha values.
The name ac is an abbreviation of "adjust color",
but is also a mnemonic aid for providing "air conditioning".
Value
A color vector of the same length as col,
transformed by adjustcolor.
See Also
seecol for plotting/seeing color palettes;
usecol for using color palettes;
simcol for finding similar colors;
newpal for defining new color palettes;
grepal for finding named colors.
Other color functions:
demopal(),
grepal(),
newpal(),
seecol(),
shades_of(),
simcol(),
usecol()
Examples
ac("black") # using alpha = .5 by default
# multiple colors:
cols <- ac(c("black", "gold", "deepskyblue"), alpha = .50)
seecol(cols, main = "Transparent colors")
# multiple alphas:
blacks <- ac("black", alpha = 5:0/5)
seecol(blacks, main = "One col several alpha values")
bgc <- ac(c("black", "gold"), alpha = 1:6/6)
seecol(bgc, main = "More alpha values than cols")
# Using a color palette:
seecol(ac(pal_unikn_pref, 2/3), main = "Adding color transparency by ac()")
# Color names:
seecol(ac(col = pal_unikn_pref, alpha = c(1/5, 4/5), use_names = TRUE))
seecol(ac(col = pal_unikn_pref, alpha = c(1/5, 4/5), use_names = FALSE))