Question

想象一下，有充分的理由要使多面ggplot中的每一行具有不同比例的mpg之类的变量。

如何将y轴标签放在小平面条标签内，以便非常清楚地由y轴标签而不是小平面描述单位？尤其欢迎修改下面代码的建议。

在您想象这种情况时，请也想像一下有充分的理由不将条带放在右边，而不要将双条带放在右边。 facet_wrap会发生这种情况，并帮助我在“迷你”，“适度”和“肌肉”与y轴刻度之间获得“每加仑英里” :-)谢谢！

library(tidyverse)
data(mtcars)

mtcars %>% 
    mutate(transmission=c("real", "robot")[am+1]
           , engine=c("mini", "modest", "muscle")[cyl/2-1]) %>% 
    ggplot(aes(wt*1000, mpg)) +
    geom_point() +
    facet_grid(engine ~ transmission, switch = "y", scales = "free") +
    labs(x="vehicle weight (lbs)", y = "miles per gallon" ) +
    theme_classic() +
    theme( panel.spacing=unit(2, "lines")
          , strip.placement.y = "outside"
          , strip.background = element_blank()
          , strip.text = element_text(face = "bold")
          )

Answer 1

我的方法：在构面名称中包含单位，然后在名称和单位之间输入换行符。

library(tidyverse)
data(mtcars)

data <- mtcars %>% 
  mutate(transmission=c("real", "robot")[am+1]
         , engine=c("mini", "modest", "muscle")[cyl/2-1]

         # Later, we're going to insert the line break at a fixed point. To prepare:
         # Change strings to a consistent width, one greater than the length of the longest string. 
         # In this case, the longest name is 6 characters long, 
         # so we'll pad the strings to be 7 characters wide. 
         , engine_l = str_pad(engine, width = 7, side = "right") %>%
                      # add unit to end of string
                      paste0("mpg")
         ,
         # check that string length is consistent - should be 10 for all rows.
         str_length(engine_l))


data %>%
  ggplot(aes(wt*1000, mpg)) +
  geom_point() +
  facet_grid(engine_l ~ transmission, switch = "y", scales = "free",

             # the labeller feature allows us to customize the facet labels. 
             # In this case, we enter a line break after 6 characters, the length of the longest name.
             labeller = labeller(engine_l = label_wrap_gen(6))) +

  # remove units from y axis label
  labs(x="vehicle weight (lbs)", y = "" ) +
  theme_classic() +
  theme( panel.spacing=unit(2, "lines")
         , strip.placement.y = "outside"
         , strip.background = element_blank()
         , strip.text = element_text(face = "bold")
  )

我一直在尝试用“加仑/英里”代替“ mpg”，但现在还无法破解。也许其他人对此会有想法。：）

此外，这是有关贴标签机的更多信息：https://ggplot2.tidyverse.org/reference/labeller.html

带facet_grid的带标签内部的y轴标签

1 个答案: