在ggplot中为每个组插入垂直线

Question

dat <- data.frame(id = rep(1:4,each = 7), year = rep(2012:2018, times = 4),  
              y = runif(28), start = rep(2012:2015,each = 7), end = rep(2014:2017,each = 7))

ggplot(dat, aes(x = year, y = y)) + geom_line() + facet_wrap(~id) 

如何为每个id插入两条垂直线，其位置由相应的起点和终点列给出？

Answer 1

试试这个：

library(dplyr)
library(tidyr)
vlines <- dat %>% 
  select(id,start,end) %>% 
  distinct() %>% 
  gather(key = grp,value = x,start,end)

ggplot(dat, aes(x = year, y = y)) + 
  geom_line() + 
  facet_wrap(~id) +
  geom_vline(data = vlines,aes(xintercept = x))