Rでfivethirtyeightのカラーパレット

538_colour.R

# fivethirty eight color palette
# タナカケンタ (鶴見教育工学研究所)
# ggthemesパッケージで提供されているパレットが3色しかないため、Pythonのmatplotlibのstyle sheetから借用して6色に
# パレットの作り方は以下を参考にした
# https://meghan.rbind.io/blog/2022-10-11-creating-custom-color-palettes-with-ggplot2/

fivethirtyeight_color <- function(...) {

  fivethirtyeight_colors <- c(
    `blue`     = "#008fd5",
    `red` = "#fc4f30",
    `yellow`     = "#e5ae38",
    `green`    = "#6d904f",
    `gray`   = "#8b8b8b",
    `purple` = "#810f7c")

  cols <- c(...)

  if (is.null(cols))
    return (fivethirtyeight_colors)

  fivethirtyeight_colors[cols]
}

fivethirtyeight_palette <- function(palette = "main", ...) {

  fivethirtyeight_palettes <- list(
    `main` = fivethirtyeight_color("blue", "red", "yellow", "green", "gray", "purple"),
    
    `highlight` = fivethirtyeight_color("red", "gray")
  )

  fivethirtyeight_palettes[[palette]]

}

palette_gen <- function(palette = "main", direction = 1) {

  function(n) {

    if (n > length(fivethirtyeight_palette(palette)))
      warning("Not enough colors in this palette!")

    else {

      all_colors <- fivethirtyeight_palette(palette)

      all_colors <- unname(unlist(all_colors))

      all_colors <- if (direction >= 0) all_colors else rev(all_colors)

      color_list <- all_colors[1:n]

    }
  }
}

palette_gen_c <- function(palette = "main", direction = 1, ...) {

  pal <- fivethirtyeight_palette(palette)

  pal <- if (direction >= 0) pal else rev(pal)

  colorRampPalette(pal, ...)

}

scale_fill_fivethirtyeight <- function(palette = "main", direction = 1, ...) {

  ggplot2::discrete_scale(
    "fill", "fivethirtyeight",
    palette_gen(palette, direction),
    ...
  )
}

scale_colour_fivethirtyeight <- function(palette = "main", direction = 1, ...) {

  ggplot2::discrete_scale(
    "colour", "fivethirtyeight",
    palette_gen(palette, direction),
    ...
  )
}

scale_color_fivethirtyeight <- scale_colour_fivethirtyeight

scale_color_fivethirtyeight_c <- function(palette = "main", direction = 1, ...) {

  pal <- palette_gen_c(palette = palette, direction = direction)

  scale_colour_gradient2(low = fivethirtyeight_palette("main")[1], mid = fivethirtyeight_palette("main")[3], high = fivethirtyeight_palette("main")[2], ...)

}