向每个多面ggplot2添加自定义的多个geom_vline

如何解决向每个多面ggplot2添加自定义的多个geom_vline

我有一个数据集，其中每个物种都与另一物种的特定密度（数字）和类型（数字）混合。我想在ggplot的每个facet_grid面板中添加两种垂直线：（a）固定密度/类型的固定线。例如1000/1 = 1000、1000 / 6 = 166.7、10000 / 1 = 10000、10000 / 6 = 1666.7

set.seed(111)
count <- rbinom(500,100,0.1) 
species <- rep(c("A","B"),time = 250)
density <- rep(c("1000","10000","1000","10000"),time = 125)
type <- rep(c("1","1","6","6"),time = 125)
df <- data.frame(species,density,type,count) # I feel too naiive,but I'm not able to get all the treatments filled. Gah.

ggplot(df,aes(x= count,colour = species,fill = species)) + 
   geom_histogram(position="identity",alpha=0.5) + 
   theme_bw() + ylab("Frequency") + 
   facet_grid(species ~ type + density) + 
   theme(panel.grid.major = element_blank(),panel.grid.minor = element_blank()) +
   theme(legend.position = "none") + theme(aspect.ratio = 1.75/1)