In this tutorial, we will learn how to change the axis title bold font with ggplot2 in R. Let us load the packages needed including tidyverse and palmerpenguins for penguins data.
1 2 3 | library(tidyverse)library(palmerpenguins)theme_set(theme_bw(16)) |
A plot with default font for axis title text
Let us make a simple scatter plot using ggplot2 to see how the default font for both x and y-axis title looks like.
1 2 3 4 5 6 7 | penguins %>% drop_na() %>% ggplot(aes(x = flipper_length_mm, y = bill_length_mm, color = species)) + geom_point() ggsave("how_to_make_axis_title_bold_font_ggplot2.png") |
Make Axis Title Text Bold Font with element_text()
We can change the appearance text elements of a plot made with ggplot2 using theme element element_text() function. To make both x and y-axis’s title text in bold font, we will use axis.title argument to theme() function with element_text(face=”bold”).
1 2 3 4 5 6 7 8 | penguins %>% drop_na() %>% ggplot(aes(x = flipper_length_mm, y = bill_length_mm, color = species)) + geom_point() + theme(axis.title = element_text(face="bold"))ggsave("make_axis_title_bold_font_ggplot2.png") |
Note now both x and y axis’s title text are in bold font.
Make X and Y Axis Title Text Bold Font Separately with element_text()
In the above example, we changed both x and y-axis’s title text into bold. We can also specify either x or y-axis alone to customize the look of text using element_text(). For example, to make the title text of x-axis aloine in bold font, we will use “axis.title.x”
1 2 3 4 5 6 7 | penguins %>% drop_na() %>% ggplot(aes(x = flipper_length_mm, y = bill_length_mm, color = species)) + geom_point() + theme(axis.title.x = element_text(face="bold")) |
Similarly, to make the y-axis title text’s font into bold we can use “axis.title.y” as shown below.
1 2 3 4 5 6 7 | penguins %>% drop_na() %>% ggplot(aes(x = flipper_length_mm, y = bill_length_mm, color = species)) + geom_point() + theme(axis.title.y = element_text(face="bold")) |
