R/scale_fill_EJ.R

In eugejoh/RpalEJ: Personalized Colour Palette for ggplot2

#' Load ggplot2 scale for colour aesthetic options based on EJ colours
#'
#' @param palette Character name of palette in EJ_palettes
#' @param discrete Boolean indicating whether the discrete variable used
#' @param reverse Boolean indicating whether the palette should be reversed
#' @param ... Additional arguments to pass to discrete_scale() or scale_color_gradientn()
#'
#' @importFrom ggplot2 scale_colour_manual scale_fill_gradientn discrete_scale
#' @importFrom grDevices colorRampPalette
#'
#' @return vector() of selected colours based on palette argument
#'
#' @author Eugene Joh, MPH \email{ejoh@bu.edu}
#'
#' @export
#'
#' @examples
#' data(mtcars)
#'
#' data(mtcars)
#' ggplot(mtcars, aes(x=wt,y=disp, col=as.factor(gear), size=mpg)) +
#'   geom_point() +
#'   scale_colour_EJ(palette="main", discrete=TRUE, reverse=TRUE)
#'
scale_fill_EJ <- function(palette = "main", discrete = TRUE, reverse = FALSE, ...) {
  pal <- EJ_pal(palette = palette, reverse = reverse)

  if (discrete) {
    discrete_scale("fill", paste0("EJ_", palette), palette = pal, ...)
  } else {
    scale_fill_gradientn(colours = pal(256), ...)
  }
}