R/palette.R

In ggokabeito: 'Okabe-Ito' Scales for 'ggplot2' and 'ggraph'

#' Okabe-Ito Palette
#'
#' `palette_okabe_ito()` is a wrapper around `palette.colors()` that returns the
#' Okabe-Ito palette in R 4.0.0 or greater. `palette_okabe_ito()` returns an
#' unnamed vector of colors for better use with ggplot2. Additionally, black is
#' the last color returned by `palette_okabe_ito()` when 9 colors are needed
#' instead of the first, as in `palette.colors()`.
#'
#' @param order A numeric vector, the order of the colors
#' @inheritParams grDevices::palette.colors
#'
#' @return A character vector of hex codes
#' @export
#'
#' @examples
#'
#' palette_okabe_ito()
#'
#' palette_okabe_ito(order = c(2, 3, 5), alpha = 0.9)
palette_okabe_ito <- function(order = 1:9, alpha = NULL, recycle = FALSE) {
  stopifnot(is.numeric(order), all(order > 0))
  if (!is.null(alpha)) {
    stopifnot(is.numeric(alpha), alpha >= 0, alpha <= 1)
  }
  stopifnot(is.logical(recycle))

  palette_colors(
    palette = "Okabe-Ito",
    alpha = alpha,
    recycle = recycle
  )[order]
}

palette_colors <- function(...) {
  unname(palette.colors(n = 9, ...)[c(2:9, 1)])
}