Latex2exp (TeX command) affects label alignment in ggplot?

Question

A geom_boxplot that has x-axis labels with linebreaks ("\n") works great.

library(ggplot2)
library(latex2exp)
theme_set(theme_grey())

set.seed(10)
df <- data.frame(y=rnorm(120), 
                 x=rep(c("bar", 
                         "long\ncategory\nname", 
                         "longspacesuperscript\n(mm$^{2}$)"
                          ), 
                       each=40)
                  )

#Normal boxplot labels with line breaks
p1 <- ggplot(data = df, aes(x, y)) + 
  geom_boxplot() +
  scale_x_discrete() +
  ggtitle("No latex2exp (TeX command) used line breaks in x axis labels work, alignment ok")

print(p1)

#Boxplot labels using TeX
p2 <- ggplot(data = df, aes(x, y)) + 
     geom_boxplot() +
     scale_x_discrete(labels = latex2exp::TeX) +
     ggtitle("Latex2exp (TeX command) affect label alignment??")


print(p2)

# We can change the position of the labels in the plot, 
# but not within the textbox that the label seems to be nested in?
p3 <- p2 + theme_set(theme(axis.text.x=element_text(vjust=-1))) +
        ggtitle("Latex2exp (TeX command) label position adjusted")
print(p3)

Latex alignment commands in TeX() didnt work \centre \raggedleft etc.

Question(s): How can you change the alignment within the latex2exp::TeX() environment? Does that work in ggplot labels ? (without manually adding the label text, i.e. using default label names based on data (factor) naming, as I sort of did in the example)?

Or maybe a complete work around to have expected behavior and still used LaTeX within ggplot?

Based on comment of shafee I added this expected plot with center alignment and no overriding of the bottom x (similar as first plot but with correct LaTeX interpretation)

Is the 3rd plot your expected plot? I mean it seems to work in the 3rd one, right? — shafee, Jul 11 '22 at 11:05
I have added a 4th plot to show the difference and clarify what goes wrong in my opinion. All labels are suddenly left aligned and the superscripts stretches' (see thirdbox bracket closing and white space) due to TeX usage. — Sander van Delden, Jul 11 '22 at 15:17
Ok thanks. But must the solution use latex2exp? or also other workaround would work for you that gets the expected plot? — shafee, Jul 11 '22 at 16:27
There's a possible way (and actually easier than writing latex expression and data frame oriented) to get that expected plot using `ggplot2` but not using latex expression and `latex2exp` package. — shafee, Jul 11 '22 at 17:13
Please tell me. I use latex2exp mainly for math symbols, sub and superscript. So if this is possible with another package or ggplot2 itself let me know. — Sander van Delden, Jul 11 '22 at 17:35

score 1 · Accepted Answer · answered Jul 11 '22 at 17:43

1

You can obtain that plot using html or markdown math expression along with functions from ggtext package.

library(ggplot2)
library(ggtext)

set.seed(10)
df <- data.frame(
    y = rnorm(120),
    x = rep(
        c(
            "bar",
            "long<br>category<br>name",
            "longspacesuperscript<br>(mm<sup>2</sup>)"
        ),
        each = 40
    )
)

ggplot(data = df, aes(x, y)) +
    geom_boxplot() +
    ggtitle("This works using html expression with ggtext package") +
    theme(
        axis.text.x = ggtext::element_markdown()
    )

answered Jul 11 '22 at 17:43

shafee

15,566
3
19
47

1

Great and for math symbols ggtext understands this syntax: http://www.alanwood.net/demos/symbol.html (Character entity) e.g. α or Π Thanks, I will be using this a lot ! – Sander van Delden Jul 11 '22 at 18:26
Yes, you can do a lot, in this method and I think its easier and flexible than using latex expression – shafee Jul 11 '22 at 18:27

Latex2exp (TeX command) affects label alignment in ggplot?

1 Answers1