如何在ggplot2图中具有两个源标题? [英] How to have two source captions in a ggplot2 graph?

问题描述

我正在尝试在ggplot2图形中添加第二个标题.类似于这位经济学家的图表

I'm trying to add a second caption in my ggplot2 graph. Similar to how this graphic was done by this economist

这是我制作的一个基本情节，我知道如何在右下角添加一个标题，但是如何在左下角添加另一个标题

Here is a basic plot I made where I know how to add one caption on the bottom right, but how can I add another one to the bottom left

ggplot(mtcars, aes( mpg, hp)) +
  geom_point() +
  labs(title = "MTCARS MPG ~ HP",
       caption = "Source: mtcars dataset") 

推荐答案

与往常一样，您有两个选择-在图外进行注释，或者创建两个(或三个！)图并将它们组合起来.

As usual you have two options - either annotation outside the plot, or you create two (or three!) plots and combine them.

两个选项都需要反复试验.希望您不会经常需要这种方法，也不需要根据不同的比例将其完全自动化.

Both options require a bit of trial and error. Hopefully you won't need that very often and not need to fully automate it depending on different scales etc.

library(ggplot2)
library(patchwork)

textframe <- data.frame( #making the frame for the text labels.
    x = c(-Inf, Inf),
    y = -50,
    labels = c("Source1: mtcars dataset", "Source2: Not mtcars dataset"))

图外的

选项1批注

# requires manual trial and error with plot margin and y coordinate... 
# therefore less optimal

  ggplot(mtcars, aes( mpg, hp)) +
  geom_point() +
    geom_text(data = textframe, aes(x, y, label = labels), hjust = c(0,1)) +
    coord_cartesian(ylim = c(0,350), clip = 'off') +
    theme(plot.margin = margin(b = 50, 5,5,5, unit = 'pt'))

选项2两个图，将它们组合在一起.在这里使用 Patchwork .我个人更喜欢此选项.

option 2 Two plots, combining them. Here using patchwork. I personally prefer this option.

p1 <- 
  ggplot(mtcars, aes( mpg, hp)) +
  geom_point() 

p2 <- 
  ggplot(mtcars, aes( mpg, hp)) +
    geom_blank() +
    geom_text(data = textframe, 
              aes(x, y = Inf, label = labels), 
              hjust = c(0,1), 
              vjust = 1) +
    theme_void() 

  p1/p2 +plot_layout(heights = c(1, 0.1))

^{由 reprex软件包(v0.3.0)创建于2020-04-04 sup>}

^{Created on 2020-04-04 by the reprex package (v0.3.0)}

这篇关于如何在ggplot2图中具有两个源标题?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！