获取"scale_fill_grey"函数中使用的十六进制颜色代码

Question

我想获取scale_fill_grey函数用来填充由以下代码生成的条形图类别的十六进制代码:

library(ggplot2)

data <- data.frame(
  Meal = factor(c("Breakfast","Lunch","Dinner","Snacks"), 
  levels=c("Breakfast","Lunch","Dinner","Snacks")),
  Cost = c(9.75,13,19,10.20))

ggplot(data=data, aes(x=Meal, y=Cost, fill=Meal)) +
    geom_bar(stat="identity")  +
    scale_fill_grey(start=0.8, end=0.2)

Answer 1

scale_fill_grey()grey_pal()从scales包中使用,而包又使用grey.colors().因此,您可以生成您使用的四种颜色的比例代码,如下所示:

grey.colors(4, start = 0.8, end = 0.2)
## [1] "#CCCCCC" "#ABABAB" "#818181" "#333333"

这显示了颜色的图

image(1:4, 1, matrix(1:4), col = grey.colors(4, start = 0.8, end = 0.2))