r-在上面和下面穿插放置标签

Question

我正在使用ggrepel为ggplot图添加标签。为了更好地利用绘图中的空间；upper_ value"；下面的"；bottom_ value"；沿着x轴散布。

问题是，即使我相应地设置了nudge_y，底部标签也会一直显示在顶部标签旁边。

以下是我尝试过的：

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使用负值以向下推动：

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))