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rggplot2ggrepel

Mulitple color in geom_text ggplot2 figure

I would need help in order to color specific part of geom_text label within a ggplot2 figure.

Here is the code I use to produce the example :

library(ggrepel)
set.seed(42)

dat <- subset(mtcars, wt > 2.75 & wt < 3.45)
dat$car <- rownames(dat)

dat$colored_text <- "/A"
dat$car2 <- paste0(dat$colored_text,'-',dat$car)


p <- ggplot(dat, aes(wt, mpg, label = car2)) +
  geom_point(color = "red")

p1 <- p + geom_text() + labs(title = "geom_text()")

Here is the result of p1 :

enter image description here

And I would like to color each / in green and each Letters A in blue and get something like :

enter image description here

DOes someone have an idea to do that please ?

Solution

  • One option to achieve your desired result would be the ggtext package which offers increased text rendering possibilities compared to geom_text and which allows to style text via markdown and or HTML/CSS like so:

    library(ggplot2)
library(ggtext)

set.seed(42)

dat <- subset(mtcars, wt > 2.75 & wt < 3.45)
dat$car <- rownames(dat)

dat$colored_text <- "<span style='color: green'>/</span><span style='color: blue'>A</span>"
dat$car2 <- paste0(dat$colored_text,'-',dat$car)

ggplot(dat, aes(wt, mpg, label = car2)) +
  geom_point(color = "red") + 
  geom_richtext(fill = NA, label.colour = NA) + 
  labs(title = "geom_richtext()")

    EDIT Adapting the approach suggested by the author of ggrepel to your case you could get your desired result with ggrepel like so:

    library(ggplot2)
library(ggrepel)

dat <- subset(mtcars, wt > 2.75 & wt < 3.45)
dat$car <- rownames(dat)

phantom <- function(x) {
  paste0('phantom("', x, '")')
}

quotes <- function(x) {
  paste0('"', x, '"')
}
dat$label_green <- paste(quotes("/"), phantom('A'), quotes("-"), phantom(dat$car), sep = " * ")
dat$label_blue <- paste(phantom('/'), quotes("A"), quotes("-"), phantom(dat$car), sep = " * ")
dat$label_black <- paste(phantom('/'), phantom('A'), quotes("-"), quotes(dat$car), sep = " * ")

ggplot(dat, aes(wt, mpg)) +
  geom_point(color = "red") + 
  geom_text_repel(aes(label = label_green), color = "green", parse = TRUE, seed = 1) +
  geom_text_repel(aes(label = label_blue), color = "blue", parse = TRUE, seed = 1) +
  geom_text_repel(aes(label = label_black), color = "black", parse = TRUE, seed = 1) +
  labs(title = "Multi-color geom_repel_text()")