r - 没有 geom 的 ggforce 注释？

Question

我想创建一个 ggforce 注释(通过 geom_mark_* 函数)，但我不希望 geom 的形状可见。我尝试过将各种 alpha 级别设置为零但无济于事。换句话说，我想保留注释线和标签，但不保留下面的表示中围绕该点的圆圈。我该如何隐藏它？

编辑:为了响应下面的一种可能的解决方案，我无法使用颜色参数，因为我有不止一种背景颜色。

library(tidyverse)
#> Warning: package 'ggplot2' was built under R version 4.0.5
#> Warning: package 'dplyr' was built under R version 4.0.5
library(ggforce)
#> Warning: package 'ggforce' was built under R version 4.0.4

df2 <- tibble(
  x = 1:10,
  y = rnorm(10),
  z = LETTERS[1:10]
)

ggplot(df2, aes(x, y)) +
  geom_point() +
  geom_mark_circle(
    aes(label = z, filter = x == 5)
  ) +
  annotate(
    "rect",
    xmin = 0, 
    xmax = 5,
    ymin = -Inf,
    ymax = Inf,
    fill = "steelblue",
    alpha = 0.3
  ) +
  annotate(
    "rect",
    xmin = 5, 
    xmax = Inf,
    ymin = -Inf,
    ymax = Inf,
    fill = "firebrick",
    alpha = 0.3
  )

^{由 reprex package 于 2021 年 9 月 2 日创建(v1.0.0)}

Answer 1

我在工作中使用的一个技巧是将背景设置为与标记相同的颜色:

ggplot(df2, aes(x, y)) +
  geom_point() +
  geom_mark_circle(
    aes(label = z, filter = x == 5), color = "grey90"
  ) + 
  theme(panel.background = element_rect("grey90"))

编辑

ggplot(df2, aes(x, y)) +
  geom_point() +
  geom_mark_circle(
    aes(label = z, filter = x == 5), expand = unit(0, "mm")
  ) +
  annotate(
    "rect",
    xmin = 0, 
    xmax = 5,
    ymin = -Inf,
    ymax = Inf,
    fill = "steelblue",
    alpha = 0.3
  ) +
  annotate(
    "rect",
    xmin = 5, 
    xmax = Inf,
    ymin = -Inf,
    ymax = Inf,
    fill = "firebrick",
    alpha = 0.3
  )