如何在ggplot2 R中向轴添加子文本

Question

对于主y轴和x轴,我有通用标题,如"Tank's Ratio"和"Counts".我想要第二行标签,我指定比率和计数.例如.就在"Tank's Ratio"之下,我希望"#in water /#in sand"中的字体较小,但是沿着y轴.类似地,对于x轴.这是基本代码

data <- data.frame(set = c(1, 1, 1, 2, 2, 3, 3, 3, 3, 3, 4, 4), density = c(1, 3, 3, 1, 3, 1, 1, 1, 3, 3, 1, 3), counts = c(100, 2, 3, 76, 33, 12, 44, 13, 54, 36, 65, 1), ratio = c(1, 2, 3, 4, 1, 2, 3, 4, 5, 6, 90, 1))

library(ggplot2)

ggplot(data, aes(x = counts, y = ratio)) + 
  geom_point() + 
  ylab("Tank's Ratio") + 
  xlab("Counts") 

Answer 1

这不是最优雅的解决方案，但希望它有所帮助：

library(ggplot2)
library(gridExtra)
library(grid)

首先，创建不带 ylab 的绘图：

g <- ggplot(data, aes(x = counts, y = ratio)) + 
  geom_point()  +
  ylab("") + 
  xlab("Counts") 

然后为两个轴添加副标题：

g2 <- grid.arrange(g, 
                   bottom = textGrob("in water/ # in sand", 
                                     x = 0.55, y = 1, gp = gpar(fontsize = 9)),
                   left = textGrob("in water/ # in sand",  rot = 90, 
                                   x = 1.5, gp = gpar(fontsize = 9)))

最后，添加y轴的描述

grid.arrange(g2, 
             left = textGrob("Tank's Ratio",  rot = 90, 
                             x = 1.7, gp = gpar(fontsize = 12)))