R/transparentColor.R

In rangeBuilder: Occurrence Filtering, Geographic Standardization and Generation of Species Range Polygons

##' Define colors with transparency
##' 
##' Converts a named color and opacity and returns the proper RGB code.
##' 
##' 
##' @param namedColor a color name
##' @param alpha a transparency value between 0 and 1, where 0 is fully
##' transparent
##' @return Returns the transparent color in RGB format.
##' @author Pascal Title
##' @keywords manip
##' @export

transparentColor <- function(namedColor, alpha = 0.8) {
	res <- col2rgb(namedColor) / 255;
	return(rgb(red = res[1,], green = res[2,], blue = res[3,], alpha = alpha));
}