R/mycolors.R

In atusy/mytools: Small tools for data analysis

#' color LUT
#' @param palette palette to be used as LUT. either pcol (= pseudocolor) or gray. It is ignored when LUT is specified.
#' @param n number of output colors. When n is more than number of colors in the specified palette, output contains duplicated colors.
#' @param dec FALSE in default outputs a vector of RGB colors. TRUE outputs matrix whose columns are R, G, and B, and whose values are in decimals.
#' @param LUT NULL in default will be ignored. You can input a vector of color names.
#' @importFrom grDevices col2rgb
#' @export
mycolors <- function(palette = c('pcol', 'gray'), n = NULL, dec = FALSE, LUT = NULL) {
  if(is.null(LUT)) LUT <- colors[[match.arg(palette)]]

  if(is.null(n)) {
    #return all colors
    output <- LUT
  } else {
    #return n colors
    #n > length(LUT) is allowed by returning some duplicates
    output <- LUT[seq(1, length(LUT), length.out = n)]
  }
  if(dec){
    #TRUE returns a matrix like R=0,...; G=255,...; B=129,....
    #FALSE returns a vector like #000000, #000001,...
    output <- t(col2rgb(output))
    colnames(output) <- c('R', 'G', 'B')
  }

  #return available LUTs or colors chosen from a LUT
  output
}