Colour utilities

Usage

alphacol(col, alpha = FALSE)

Arguments

col: vector of any of the three kinds of R color specifications, i.e., either a color name (as listed by colors()), a hexadecimal string of the form "#rrggbb" or "#rrggbbaa" (see rgb), or a positive integer i meaning palette()[i]. Non-numeric values are coerced to character.
alpha: logical value indicating whether the alpha channel (opacity) values should be returned.

Description

alphacol adds an alpha value to a colour specification and convert to a hexadecimal colour string.

Examples

# Alphas
alphacol('red') # do nothing

[1] "#ff0000"
alphacol('red', 10)

[1] "#ff0000ff"
alphacol('#aabbcc', 5)

[1] "#aabbccff"
alphacol(4, 5)

[1] "#0000ffff"