CODEWITHSUNDEEP
rparsingggplot2expressionplotmath
Indrajeet Patil
Indrajeet Patil

Reputation: 4879

using `plotmath` to display combination of subscript and `[ ]`

I want to create a plot where I want to display a mean value and confidence intervals for this mean value. To do so, I am using plotmath. Here is something I have done that works-

library(ggplot2)

ggplot(mtcars, aes(as.factor(cyl), wt)) + geom_boxplot() +
  labs(
    title = "Mean weight:",
    subtitle = parse(text = paste(
      "list(~italic(mu)==", 3.22, ",", "CI[95~'%'] ", "(", 2.87, ",", 3.57, "))",
      sep = ""
    ))
  )

Created on 2019-08-25 by the reprex package (v0.3.0)

But this is not what I actually want. The format in which I instead want to display these results is the following-

enter image description here

So there are two things I can't seem to figure out how to do using plotmath:

  1. 95 % should instead be 95%

  2. Use [ instead of (

How can I do this?

P.S. It is important, for reasons to complicated to explain here, for me to have list inside the paste function because I want to save these expressions as a character-type column in a dataframe. This is why I haven't accepted the two solutions provided below.

Upvotes: 2

Views: 374

Answers (4)

Edo
Edo

Reputation: 7818

This solution keeps list and paste.

library(ggplot2)

ggplot(mtcars, aes(as.factor(cyl), wt)) + geom_boxplot() +
  labs(
    title = "Mean weight:",
    subtitle = parse(text = paste(
      "list(~italic(mu)==", 3.22, ",", "CI[95*'%'] ", "*'['*", 2.87, ",", 3.57, "*']')",
      sep = ""
    ))
  )

enter image description here

Upvotes: 3

Claus Wilke
Claus Wilke

Reputation: 17790

I'll assume that what you actually care about is that the output looks right, not that plotmath is used. You can use the ggtext package I'm currently developing, which gives you the possibility to use simple markdown/HTML inside of ggplot2. I generally find it much easier to create basic math expressions that way than wrangling with plotmath. And you don't have to work with R expressions at all, the input is always a simple character string.

# this requires the current development versions of ggplot2 and ggtext
# remotes::install_github("tidyverse/ggplot2")
# remotes::install_github("clauswilke/ggtext")

library(ggplot2)
library(ggtext)

ggplot(mtcars, aes(as.factor(cyl), wt)) + 
  geom_boxplot() +
  labs(
    title = "Mean weight:",
    subtitle = "*&mu;* = 3.22, CI<sub>95%</sub>[2.87, 3.57]"
  ) +
  theme(plot.subtitle = element_markdown())

Created on 2019-12-02 by the reprex package (v0.3.0)

Upvotes: 2

G. Grothendieck
G. Grothendieck

Reputation: 269586

Use the formula shown:

ggplot(mtcars, aes(as.factor(cyl), wt)) + geom_boxplot() +
  labs(
    title = "Mean weight:",
    subtitle = ~italic(mu) == 3.22*', '*"CI"[95*'%']*group('[',2.87*','*3.57,']')
  )

screenshot

Upvotes: 4

akrun
akrun

Reputation: 887118

An option would be bquote

library(ggplot2)
ggplot(mtcars, aes(as.factor(cyl), wt)) + 
       geom_boxplot() +
       labs(title = "Mean weight:", 
        subtitle = bquote(italic(mu)~"= 3.22,"~CI[95*'%']~"["*"2.87, 3.57"*"]"))

enter image description here

Upvotes: 3

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