R ggrides包装图的中线（未中）

由陌上桑发布于 2020-05-24 02:37:56 rggplot2tidyverseggridges

I'd like to draw a line through my rideplots for the mean. The built-in quantile arguments draw a line in the style I want, but at the median. How can I draw one at the mean, preferably without using geom_vline() or pluck at the ggplot build object but staying in the ggridges ecology?

#adding a column for the mean of each Species of the iris dataframe
iris_meaned <- iris %>%
  group_by(Species) %>% 
  mutate(mean_petal_len = mean(Petal.Length)) %>% 
  ungroup()


iris_meaned %>% 
  ggplot() +
  geom_density_ridges(aes(x = Petal.Length, y = Species, fill = Species), 
                    quantile_lines = T, quantiles = 2)  + #adding lines for the median
  geom_text(aes(x = mean_petal_len, y = Species,
                label = round(mean_petal_len, 2)), size = 2, nudge_x = 0.03, nudge_y = 0.35) +
  theme_classic() +
  theme(axis.title = element_blank(), 
        legend.position = "None")

小偏执i 2020-05-24 02:37:57 回复

You can provide an arbitrary function to the argument quantile_fun. The function has to take a numeric vector as the first argument, and the number of quantiles as the second. But it's fine to ignore the second argument. The mean() function satisfies these criteria, and thus quantile_fun = mean creates vertical lines at the mean.

请注意，在您的示例中，您将一遍又一遍地绘制文本标签。我已经修复了代码，使其可以正常工作。

library(tidyverse)
library(ggridges)

iris_meaned <- iris %>%
  group_by(Species) %>% 
  summarize(mean_petal_len = mean(Petal.Length))

ggplot(iris) +
  geom_density_ridges(
    aes(x = Petal.Length, y = Species, fill = Species), 
    quantile_lines = T, quantile_fun = mean)  + 
  geom_text(
    data = iris_meaned,
    aes(x = mean_petal_len, y = Species, label = round(mean_petal_len, 2)),
    size = 2, nudge_x = 0.03, nudge_y = 0.35
  ) +
  theme_classic() +
  theme(axis.title = element_blank(), 
        legend.position = "None") 
#> Picking joint bandwidth of 0.155

^{Created on 2020-05-23 by the reprex package (v0.3.0)}