关于ggplot2：旋转geom_point形状并在线上方显示geom_text

Question

早上好。

我正在尝试使用ggplot2包绘图，但遇到以下问题：

为了使它更易于理解，这里是我想要制作的目标图像。

就像图片一样，我想要做以下事情：

1）在虚线上方放置文本“中位数”，以便清楚地看到字符。

2）旋转三角形的度数（不是^ ^而是< >），以使其有意义。

为了实现以上目标，我已经使用以下代码：

# binding the data, defining the x and y aesthetics, title, labels
w_plot <- ggplot(
  data = com_mal, 
  aes(x = reorder(name, -median_age),  y = median_age)
)

labels = c('5 yrs old', 10, 15, 20, 25, 30)

w_plot + 
  geom_linerange(
    aes(ymin = q1_age, ymax = q3_age),
    color = "#76bde0", 
    size = 6, 
    alpha = 0.7
  ) + 
  geom_point(fill = "#ed3324", colour = "white", size = 4, shape = 21) +
  geom_text(aes(y = 9, x = 15, label = '25th')) +
  geom_text(aes(y = 20, x = 15, label = '75th percentile')) +
  geom_text(aes(y = 30, x = 22, label = 'median')) +
  geom_point(aes(y = 8.25, x = 15), shape = 17) +
  geom_point(aes(y = 21.75, x = 15), shape = 17) +
  geom_point(aes(y = 29, x = 21.9), fill = "#ed3324", colour = "white", size = 4, shape = 21) +
  geom_hline(aes(yintercept = 5), linetype = 'dotted') +
  geom_hline(aes(yintercept = 10), linetype = 'dotted') +
  geom_hline(aes(yintercept = 15), linetype = 'dotted') +
  geom_hline(aes(yintercept = 20), linetype = 'dotted') +
  geom_hline(aes(yintercept = 25), linetype = 'dotted') +
  geom_hline(aes(yintercept = 30), linetype = 'dotted') +
  scale_y_continuous(breaks = seq(5, 30, by = 5), position = 'right', labels = labels) +
  coord_flip() +
  labs(title = 'Youngest Male Names',
       subtitle = 'By estimated median age for Americans alive as of Jan 1. 2014',
       x = NULL, y = NULL, caption =  'SOURCE: SOCIAL SECURITY ADMINISTRATION') +
  theme(plot.title = element_text(face = 'bold', size = 16),
        panel.grid.major = element_blank(), panel.grid.minor = element_blank(),
        axis.ticks = element_blank(), plot.caption = element_text(size = 10))

非常感谢！

- supremed14

---

请添加一些数据，以便我们能够重现这个图形。可以尝试使用geom_label()替代geom_text。 - Roman

不要使用geom_point，而是使用geom_polygon，其中你预先计算了两个三角形每个角的位置。在你的示例中，y坐标围绕y = 11居中（如果我数对了的话）。 - MrGumble

感谢您的所有答案！ :) - supremed14

Answer 1

对于三角形，您可以使用geom_text()，将family参数设置为支持该字符的字体，并对标签使用geom_label()：

 geom_text(label = "▶", size = 3, family = "HiraKakuPro-W3")
 geom_label(aes(y = 4, x = 10, label = 'median'), fill = "grey92", label.size = NA)

label.size属性可以去掉标签的轮廓，"grey92"是（大约？）背景色。

如果您想让虚线在标签后面显示，应该在绘图中添加geom_label()代码在线条之后。（还请注意，您可以在同一行代码中添加所有虚线。）

w_plot + 
  geom_linerange(
    aes(ymin = q1_age, ymax = q3_age),
    color = "#76bde0", 
    size = 6, 
    alpha = 0.7
  ) + 
  geom_point(fill = "#ed3324", colour = "white", size = 4, shape = 21) +
  geom_text(aes(y = 9, x = 15, label = '25th')) +
  geom_text(aes(y = 20, x = 15, label = '75th percentile')) +
  geom_text(aes(y = 8.25, x = 15),label = "◀", size = 3, 
            family = "HiraKakuPro-W3") +
  geom_text(aes(y = 21.75, x = 15),label = "▶", size = 3, 
            family = "HiraKakuPro-W3") +
  geom_point(aes(y = 29, x = 21.9), fill = "#ed3324", colour = "white", 
             size = 4, shape = 21) +
  geom_hline(yintercept = seq(5, 30, by = 5), linetype = 'dotted') +
  geom_label(aes(y = 30, x = 22, label = 'median'), 
             fill = "grey92", label.size = NA) +
  scale_y_continuous(breaks = seq(5, 30, by = 5), 
                     position = 'right', labels = labels) +
  coord_flip() +
  labs(title = 'Youngest Male Names',
       subtitle = 'By estimated median age for Americans alive as of Jan 1. 2014',
       caption =  'SOURCE: SOCIAL SECURITY ADMINISTRATION') +
  theme(plot.title = element_text(face = 'bold', size = 16),
        panel.grid.major = element_blank(), panel.grid.minor = element_blank(),
        axis.ticks = element_blank(), plot.caption = element_text(size = 10))

- Luca

---

@supremed14：你能在你的问题中添加dput(com_mal)的输出，以便其他人可以重现这个图吗？请还标记Luca的帖子作为答案，以帮助未来的读者。谢谢！ - Tung