更改ggplot2图例中中位数和平均值的颜色

Question

请忽略图中的随机点 - 这只是一个快速可复制的示例来说明我的意思：

ggplot(data = iris, aes(x = Sepal.Length, y = Sepal.Width, fill = Species)) + 
  geom_violin(alpha = 0.5) +
  stat_summary(aes(shape="mean",group=1),fun = "mean",
               size = 2, geom = "point", color = "black") +
  stat_summary(aes(shape = "median", group = 2), fun = "median",
               size = 2, geom = "point", color = "red") +
  labs(x = "Sepal Length", y = "Sepal Width",
       shape = "Shape", colour = "Species") +
  theme_classic()

我如何：

a).更改图例，使每个分类变量的框中间没有红点？ b).更改“形状”图例的颜色，使“均值”为黑色，“中位数”为红色？

我用 Google 搜索了一个多小时，但找不到答案，非常感谢您的帮助。谢谢！

Answer 1

图例指南中有 override.aes 参数，您可以使用它来明确设置键的美学。

library(ggplot2)

ggplot(data = iris, aes(x = Sepal.Length, y = Sepal.Width, fill = Species)) + 
  geom_violin(alpha = 0.5) +
  stat_summary(aes(shape="mean",group=1),fun = "mean",
               size = 2, geom = "point", color = "black") +
  stat_summary(aes(shape = "median", group = 2), fun = "median",
               size = 2, geom = "point", color = "red") +
  labs(x = "Sepal Length", y = "Sepal Width",
       shape = "Shape", colour = "Species") +
  guides(
    shape = guide_legend(override.aes = list(colour = c("black", "red"))),
    fill = guide_legend(override.aes = list(shape = NA))
  ) +
  theme_classic() 
#> Warning: position_dodge requires non-overlapping x intervals

更改ggplot2图例中中位数和平均值的颜色

Changing the colour of median and mean in ggplot2 legend

r

ggplot2

mean

median

violin-plot