get R color alpha value
Return the alpha transparency per R color
col2alpha(x, maxValue = 1, ...)
x
: character
R compatible color, either a color name, hex value, or a mixture of the two. Any value compatible with grDevices::col2rgb()
.maxValue
: numeric
maximum value to return, useful when the downstream alpha range should be 255. By default maxValue=1 is returned....
: Additional arguments are ignored.numeric
vector of alpha values
col2alpha(c("red", "#99004499", "beige", "transparent", "#FFFFFF00"))
Other jam color functions: alpha2col()
, applyCLrange()
, col2hcl()
, col2hsl()
, col2hsv()
, color2gradient()
, fixYellow()
, fixYellowHue()
, getColorRamp()
, hcl2col()
, hsl2col()
, hsv2col()
, isColor()
, kable_coloring()
, makeColorDarker()
, rainbow2()
, rgb2col()
, setCLranges()
, setTextContrastColor()
, showColors()
, unalpha()
, warpRamp()