ggplot中的序数上标注释R [英] Ordinal superscript in ggplot annotate R

问题描述

我希望能在将文本标签放置在ggplot图上(使用annotate)时获得一些帮助，其中文本包含上标的序数后缀(或任何适当的后缀)和计算值.尽管阅读了关于SO和SE的一些问题，但我仍然无法使它正常工作.

I'm hoping I can get some help with placing a text label on a ggplot graph (using annotate) where the text contains an ordinal suffix as superscript (or whatever the proper term is for that) and a computed value. Despite reading a few questions on SO and SE, I'm having trouble getting this to work.

这是一个最小的例子.

  # my two attempts at creating the label
  my.var = 10 / 3 # just a toy example
  my.label.expr = paste(expression("20^th*"), " decile ",  round(my.var, 4), sep = "") 
  my.label.bquote = bquote('Lift (' ~  20^th* ~ "decile) : " ~ .  
 (round(my.var, 4), sep = ""))
  test = data.frame(x = 1:10, y = 1:10)
  ggplot(aes(x = x , y= y ), data = test) + geom_point() + 
  annotate("text", label = my.label.bquote,parse = TRUE, x = 5, y = 5,    
  colour = "red", size = 7)

使用label = my.label.expr会给出错误:

# Error in parse(text = lab) : <text>:1:15: unexpected numeric constant
# 1: 20^th* decile 3.3333

使用label = my.label.bquote会导致解释器提示输入?

Using label = my.label.bquote causes interpreter to have prompt with a ?

我也尝试过使用parse = FALSE，打印my.label.expr，但是只显示文字，没有上标.使用parse = FALSE作为bquote解决方案时，它根本不打印任何内容.

I also tried with parse = FALSE, the my.label.expr prints, but just displays the text literally, no superscript. With parse = FALSE for the bquote solution, it prints nothing at all.

我觉得我对每个选项的语法都感到困惑.是否可以显示纯字母上标?任何帮助将不胜感激！

I feel like I've gotten confused between the syntax for each of these options. Is it possible to display a purely alphabetic superscript? Any help would be appreciated!

推荐答案

如何解决

my.label.expr = paste("20^{th}*' decile '*", round(my.var, 4))

ggplot(aes(x = x , y= y ), data = test) + geom_point() + 
annotate("text", label = my.label.expr, parse=TRUE,
  x = 5, y = 5, colour = "red", size = 7)

在这里，我们使用正确的?plotmath语法(将指数分组​​在括号中)将值构建为字符串，然后设置parse=TRUE以便对其进行评估.

Here we build the value as a character string with proper ?plotmath syntax (grouping the exponent in brackets) and then setting parse=TRUE so it is evaluated property.

这篇关于ggplot中的序数上标注释R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！