上下穿插放置标签

Question

我正在使用 ggrepel 向我的 ggplot 图表添加标签。为了更好地使用图中的 space，我想在“upper_value”上方添加一个标签，并在 x 轴的“bottom_value”下方添加一个标签，散布。

问题是底部标签一直显示在顶部标签旁边，即使我相应地设置了 nudge_y 也是如此。

这是我试过的方法：

set.seed(5)

library(ggplot2)
library(ggrepel)
library(dplyr)

d <- data.frame(
  x = 1:60,
  y = c(
    sample(x = seq(0,0.2,0.01), size = 20, replace = TRUE),
    sample(x = seq(0.8,1,0.01), size = 20, replace = TRUE),
    sample(x = seq(0,0.2,0.01), size = 20, replace = TRUE)
  )
) 

# add labels for high scores
d$labs[d$y >= 0.8] <- paste0("label_",letters[1:20])
    
# add a column to intersperse labels (above=1 and below=2)
d_lab <- d %>% 
  filter(!is.na(labs) ) %>% 
  mutate(lab_set = rep(c(1,2), nrow(.)/2) )

ggplot(data = d, aes(x = x, y = y), show.legend = TRUE) +
  geom_line() + 
  geom_point(data =  filter(d, !is.na(labs)), color = "red") +
  # place labels above 1.2
  geom_label_repel(
    data =  filter(d_lab, lab_set == "1"),aes(label = labs),
    segment.color = "black", 
    arrow = arrow(length = unit(0.01, "npc"), type = "closed", ends = "first"),
    fill = alpha(c("white"),0.5),
    #show.legend = FALSE,
    color = "black",
    direction = "x",
    nudge_y = 1.2
  ) +
  # place labels below 0.8 --> does not respond to nudge_y!!!
  geom_label_repel(
    data =  filter(d_lab, lab_set == "2"),aes(label = labs),
    segment.color = "black", 
    arrow = arrow(length = unit(0.01, "npc"), type = "closed", ends = "first"),
    fill = alpha(c("white"),0.5),
    #show.legend = FALSE,
    color = "black",
    direction = "x",
    nudge_y = 0.8
  ) +
  scale_y_continuous(limits = c(NA, 1.2))

Answer 1

尝试在第二个 geom_label_repel 调用中为 nudge_y 使用负值以向下微调：

ggplot(data = d, aes(x = x, y = y), show.legend = TRUE) +
  geom_line() + 
  geom_point(data =  filter(d, !is.na(labs)), color = "red") +
  # place labels above 1.2
  geom_label_repel(
    data =  filter(d_lab, lab_set == "1"),aes(label = labs),
    segment.color = "black", 
    arrow = arrow(length = unit(0.01, "npc"), type = "closed", ends = "first"),
    fill = alpha(c("white"),0.5),
    #show.legend = FALSE,
    color = "black",
    direction = "x",
    nudge_y = 1.2
  ) +
  # place labels below 0.8 --> does not respond to nudge_y!!!
  geom_label_repel(
    data =  filter(d_lab, lab_set == "2"),aes(label = labs),
    segment.color = "black", 
    arrow = arrow(length = unit(0.01, "npc"), type = "closed", ends = "first"),
    fill = alpha(c("white"),0.5),
    #show.legend = FALSE,
    color = "black",
    direction = "x",
    nudge_y = -0.25 # USE NEGATIVE VALUE HERE
  ) +
  scale_y_continuous(limits = c(NA, 1.2))

上下穿插放置标签

Place labels above and below interspersed

r

ggplot2

ggrepel