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rggplot2axis-labels

Conditional change of axis.text font family and font size creates unwanted 'gap'

I need to change the family and size of a specific x-axis element of a barplot, based on a condition.

I can successfully modify face using:

library(ggplot2)
ggplot(iris, aes(Species, Petal.Length)) + 
  geom_boxplot() + 
  coord_flip() +
  theme(axis.text.y = element_text(face = ifelse(levels(iris$Species)=="setosa","bold","italic")))

As suggested by: https://stackoverflow.com/a/20609878/8534926

However, for some reason when I try to apply family and size an empty gap is created between the axis and names.

ggplot(iris, aes(Species, Petal.Length)) + 
  geom_boxplot() + coord_flip() + 
  theme(axis.text.y = element_text(family = ifelse(levels(iris$Species)=="setosa","sans","mono")))

or

ggplot(iris, aes(Species, Petal.Length)) + 
  geom_boxplot() + coord_flip() + 
  theme(axis.text.y = element_text(size = ifelse(levels(iris$Species)=="setosa", 10, 20)))

I try to edit it using margin, but overlays can occur when the names are modified (using shiny app, for example).

what is this gap? Can I delete it?

Solution

  • The problem is fixed in the upcoming ggplot2 3.3.0, but it now triggers a warning, because this approach of formatting axis text is not reliable and could stop working at any point in the future.

    library(ggplot2) # v 3.3.0 or higher

# discouraged, triggers warning message
ggplot(iris, aes(Species, Petal.Length)) + 
  geom_boxplot() + coord_flip() + 
  theme(
    axis.text.y = element_text(
      size = ifelse(levels(iris$Species)=="setosa", 10, 20)
    )
  )
#> Warning: Vectorized input to `element_text()` is not officially supported.
#> Results may be unexpected or may change in future versions of ggplot2.

    As an alternative, the ggtext package under development attempts to provide a principle approach to this problem, by encoding the formatting instructions into the text labels.

    library(ggtext) # remotes::install_github("clauswilke/ggtext")
library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union
library(glue)
#> 
#> Attaching package: 'glue'
#> The following object is masked from 'package:dplyr':
#> 
#>     collapse

iris %>%
  mutate(
    Species = ifelse(
      Species == "setosa",
      "<span style = 'font-size:10pt'>setosa</span>",
      glue("<span style = 'font-size:20pt'>{Species}</span>")
    )
  ) %>%
  ggplot(aes(Species, Petal.Length)) + 
  geom_boxplot() + coord_flip() + 
  theme(axis.text.y = element_markdown())

    Created on 2020-01-16 by the reprex package (v0.3.0)