as.rgb: Convert color-names or RGB-code to possibly semi-transparent...

In lengning/gClinBiomarker: gClinBiomarker: an R package for clinical biomarker analyses

Description

Function takes the name of a color and converts it into the rgb space. Parameter "alpha" allows to specify the transparency within [0,1], 0 meaning completey transparent and 1 meaning completey opaque. If an RGB-code is provided and alpha != 1, the RGB-code of the transparency adapted color will be returned.

Usage

as.rgb(col = "black", alpha = 1)

Arguments

col	(character) name of the color to be converted/transformed into RGB-space (code). Only those colors can be used which are part of the set returned by function colors(). Defaults to "black".
alpha	(numeric) value specifying the transparency to be used, 0 = completely transparent, 1 = opaque.

Value

RGB-code

Author(s)

Andre Schuetzenmeister [e-mail]

Examples

# convert character string representing a color to RGB-code using alpha-channel of .25 (75\% transparent)
     as.rgb("red", alpha=.25)

# same thing now using the RGB-code of red (alpha=1, i.e. as.rgb("red"))
     as.rgb("#FF0000FF", alpha=.25)
     

lengning/gClinBiomarker documentation built on May 9, 2019, 2:55 p.m.