r - 解析字符中的数值，因为它们与`scipen`的值无关

Question

我有一个包含统计测试结果的字符表达式，我想在一个ggplot对象中解析这个表达式。但是我希望解析后的表达式看起来相同，而不管用户可能为scipen选项设置的值是什么。

默认scipen = 0（好）

library(ggplot2)

# plot is just for illustration and has nothing to do with the statistics being displayed
ggplot(mtcars, aes(wt, mpg)) + geom_smooth() + geom_point() + 
  labs(subtitle = parse(text = "list(~chi['gof']^2~(8)==617.445, ~italic(p)==4.15e-128)"))

与scipen = 999（不受欢迎的）

library(ggplot2)
options(scipen = 999)

# plot is just for illustration and has nothing to do with the statistics being displayed
ggplot(mtcars, aes(wt, mpg)) + geom_smooth() + geom_point() + 
  labs(subtitle = parse(text = "list(~chi['gof']^2~(8)==617.445, ~italic(p)==4.15e-128)"))

在不更改用户方面的选项的情况下，如何确保解析的表达式始终采用科学记数法？

标签： rggplot2expression

Answer 1

您可以简单地引用该值以确保将其解析为字符串而不是数值：

library(ggplot2)

options(scipen = 999)

ggplot(mtcars, aes(wt, mpg)) + geom_smooth() + geom_point() + 
  labs(subtitle = parse(text = "list(~chi['gof']^2~(8)==617.445, ~italic(p)=='4.15e-128')"))