如何在 ggplot2 中自定义图例？

Posted 2023-02-16

【中文标题】如何在 ggplot2 中自定义图例？

【英文标题】：How to customize a legend in ggplot2?

【发布时间】：2021-08-27 20:16:32

【问题描述】：

我有以下数据框：

df <-  tribble(~ id,       ~ type,              ~ value,
               "1",  "Quarterly",  -185.44272504185938,
               "2",  "Quarterly",  2.3461400352210546,
               "3",  "Quarterly",  -3.3506362679401747,
               "4",  "Quarterly",  12.198021733063797,
               "5",  "Quarterly",  39.16805907764865,
               "6",  "Quarterly",  29.258292527180572,
               "7",  "Quarterly",  18.605504231676832,
               "8",  "Quarterly",  61.17282084445469,
               "9",  "Quarterly",  115.76795844352,
               "10", "Quarterly",  90.3473788015599,
               "1",   "Monthly",  473.42922462885326,
               "2",   "Monthly",  -10.579657811202168,
               "3",   "Monthly",  14.88866793035703,
               "4",   "Monthly",  0.9983391011546701,
               "5",   "Monthly",  -0.8838179658391709,
               "6",   "Monthly",  78.33644128716827,
               "7",   "Monthly",  92.38129375625499,
               "8",   "Monthly",  226.60868103438406,
               "9",   "Monthly",  295.9518745997166,
               "10",   "Monthly",  412.9794644618978)

df_aux <-  tribble(~ id,    ~ type,         ~ value,
                   "1", "Yearly", 287.9864995869939,
                   "2", "Yearly", -8.233517775981113,
                   "3", "Yearly", 11.538031662416856,
                   "4", "Yearly", 13.196360834218467,
                   "5", "Yearly", 38.28424111180948,
                   "6", "Yearly", 107.59473381434884,
                   "7", "Yearly", 110.98679798793182,
                   "8", "Yearly", 287.78150187883875,
                   "9", "Yearly", 411.7198330432366,
                   "10","Yearly", 503.3268432634577)

ggplot(df, aes(reorder(id, value), value, fill = type)) +
  geom_bar(position = "stack", stat = "identity", width = .6) +
  geom_point(data = df_aux, aes(id, value), shape = 23, color = "white", size = 3) +
  scale_fill_manual(values = c("#00a79d", "#9dd4cf", "#012169")) +
  scale_y_continuous(breaks = seq(-200, 700, by = 100),
                     limits = c(-200, 700)) +
  coord_flip() +
  labs(fill = "",
       x = "",
       y = "",
       title = "Some title",
       subtitle = "Some subtitle") +
  theme_minimal()

我在这里遇到的问题首先是类型的图例，它们看起来与所需的输出不同：

但是，我怎样才能改变 id 10 的颜色而不出现在图例上？似乎ggplot2不允许手动修改图例。

【参考方案1】：

您可以使用key_glyph 指定图例形状，然后通过type 手动指定形状，就像您为fill 所做的那样。

ggplot(df, aes(reorder(id, value), value, shape = type, fill = type)) +
  geom_bar(position = "stack", stat = "identity", width = .6, key_glyph = "point") +
  geom_point(data = df_aux, aes(id, value), color = "white", size = 3) +
  scale_fill_manual(values = c("#00a79d", "#9dd4cf", "#012169"), name = "") +
  scale_shape_manual(values = c("Yearly" = 23, "Quarterly" = 22, "Monthly" = 22), name = "") +
  scale_y_continuous(breaks = seq(-200, 700, by = 100),
                     limits = c(-200, 700)) +
  coord_flip() +
  labs(fill = "",
       x = "",
       y = "",
       title = "Some title",
       subtitle = "Some subtitle") +
  theme_minimal()

编辑：如果您想单独显示 ID 10，我建议使用 ggnewscale 应用第二个填充比例。这涉及 ggplot2 的“标签外”使用，因此需要更多的争论才能使该点出现在该系列的顶部，并隐藏图例。

library(ggnewscale)
ggplot(df, aes(reorder(id, value), value, shape = type, fill = type)) +
  geom_bar(position = "stack", stat = "identity", width = .6, key_glyph = "point") +
  scale_fill_manual(values = c("#00a79d", "#9dd4cf", "#012169"), name = "") +
  scale_shape_manual(values = c("Yearly" = 23, "Quarterly" = 22, "Monthly" = 22), name = "") +
  geom_point(data = df_aux, aes(id, value), color = "white", size = 3) +
  new_scale_fill() +
  geom_bar(data = df[which(df$id == "10"),], aes(fill = type),
           position = "stack", stat = "identity", width = .6, key_glyph = "point") +
  scale_fill_manual(values = c("#68b6ea", "#9dc4dd"), name = "") +
  ...

【讨论】：

这对第一个问题真的很有帮助！我仍在努力改变与 ID 号 10l 对应的栏的颜色

已更新。还有一种方法可以更好地实现这一点，方法是创建特定于 ID 10 的新 types，并将它们隐藏在图例中。这将解决我遇到的问题，即由于新填充比例所需的绘图顺序，我的点位于 ID 10 的条形后面....