ggplot：显示两条geom_lines之间间隙的显示线

Question

我正在尝试模拟此图：

但是我不知道如何制作显示标签的线（带有标签），以显示橙色线和紫色线之间的间隙。

Answer 1

这是一种方法。我们需要为标签和细分创建一个单独的数据集。然后我们可以使用geom_line，geom_point，geom_segment和geom_label：

library(tidyverse)

# create sample data
d <- data.frame(x = rep(1:5, 2),
                y = c(1:5, 5:9),
                category = rep(c("a", "b"), each = 5),
                stringsAsFactors = FALSE)

# filter on a specific x value, and reshape the data to be "wide"
d_wide <- d %>%
  filter(x == 5) %>%
  spread(category, y)

ggplot(d, aes(x, y))+
  geom_line(aes(colour = category))+
  geom_point(aes(colour = category))+
  geom_segment(data = d_wide,
               aes(xend = x, y = a, yend = b))+
  geom_label(data = d_wide,
             aes(label = b - a, y = (b+a) / 2))