我怎样才能在我的ggplot中添加一个传奇?我在用风水线和风水带

将注释放在一起,并添加一些随机数据帧,结果是:

library(ggplot2)
disDataHeadItems <- data.frame(
  x = runif(100,1,100),
  Freq = runif(100,5,10)
)
disDataLongTail <- data.frame(
  x = runif(100,1,100),
  Freq = runif(100,5,10)
)

ggplot() +
  geom_line(data = disDataHeadItems, aes(x=x, 
                                         y=Freq)) + 
  geom_line(data = disDataLongTail, aes(x=x, 
                                        y=Freq)) +
  xlab("Item id") +
  ylab("# of occurrences") +
  scale_x_continuous(breaks=seq(5, 75, 10), expand = c(0, 0)) + 
  scale_y_continuous(expand = c(0, 0)) +
  geom_ribbon(aes(ymin=0, ymax=disDataHeadItems$Freq, 
                  x=disDataHeadItems$x, fill="#CC6666")) +
  geom_ribbon(aes(ymin=0, ymax=disDataLongTail$Freq, 
                  x=disDataLongTail$x, fill="#66CC99")) +
  geom_vline(xintercept=19, linetype="dotted")