将自定义图例添加到饼图

Question

有没有办法添加自定义图例。现在，图例显示列“a”，我们可以显示列“图例”吗？因为“图例”列既有标签又有值。我们可以这样做吗？:)

library('ggplot2')
asd <- data.frame(a = c("fds","fdsf"), b = c(3,4))
asd$legend <- paste0(asd$a,"-",asd$b)
ggplot(asd, aes(x="", y=b, fill = a)) + geom_bar(stat = "identity", width = 1) + coord_polar(theta = "y")

Answer 1

是的，只需将填充映射到legend 列：

ggplot(asd, aes(x = "", y = b, fill = legend)) + 
  geom_bar(stat = "identity", width = 1) + 
  coord_polar(theta = "y")