R/Col2.R

In ModelDataComp: Model-Data Comparison

Col2 <- structure(function(
	##title<< 
	## Adds transparency to a colour
	##description<< 
	## The function adds transparency to a vector of colours
	
	col,
	### character string of the colour
	
	alpha = 0.3,
	### transparence (0 = transparent, 1 = opaque)
	
	... 
	### further arguments (unused)
	
	##details<< 
	## The function adds transparency to a vector of colours
	
	##seealso<< 
	## 
) {
   col2 <- col2rgb(col) / 255
   col2 <- rgb(col2[1,], col2[2,], col2[3,], alpha)
   return(col2)
  ### returns a colour including transparency
}, ex=function() {
  cols <- Col2(c("red", "blue"), alpha=seq(0, 1, 0.1))
  plot.new()
  legend("top", cols, fill=cols, bg="yellow")
})