使用箭头和标签在 `ggplot2` 中绘制四分之三圆

Question

我想用箭头和标签在 ggplot2 中画四分之三圆。使用 ggplot2 和 ggforce 我发现了一些有用的东西，但它看起来非常复杂。

是否有更简单的选择来实现我想要的？

df <- data.frame(x = 100, y = 100, label = "R")

library(ggplot2)
library(ggforce)

r <- 10

ggplot(df) + 
  geom_circle(aes(x0 = x, y0 = y, r = r)) +
  geom_rect(aes(xmin = x, ymin = y, xmax = x + r + 1, ymax = x + r + 1), 
            fill = "white") +
  geom_segment(aes(x = x + r, y = y, xend = x + r, yend = y + 1), 
               arrow = arrow()) +
  annotate("text", x = df$x, y = df$y, label = df$label) + 
  theme_void()

Answer 1

这会被认为更简单吗？

ggplot(df) + 
  geom_arc(aes(x0 = x, y0 = y, r = r,
               start = 0, end = -1.5 * pi),
           arrow = arrow()) + 
  annotate("text", x = df$x, y = df$y, label = df$label) + 
  theme_void()

# equivalent to above with geom_text instead; I'm not sure if your actual use
# case has preference for one or the other
ggplot(df) + 
  geom_arc(aes(x0 = x, y0 = y, r = r,
               start = 0, end = -1.5 * pi),
           arrow = arrow()) + 
  geom_text(aes(x = x, y = y, label = label)) + 
  theme_void()

使用箭头和标签在 `ggplot2` 中绘制四分之三圆

Draw three-quarter-circle in `ggplot2` with arrow and label

r

ggplot2

ggforce