Talk given at rstudio::conf 2020, January 30, 2020.

1. Spruce up your ggplot2 visualizations
with formatted text
Claus O. Wilke
The University of Texas at Austin
https://wilkelab.org/ggtext
@clauswilke clauswilke

2. A common problem:
Mixing italics and normal text in ggplot

3. https://stackoverflow.com/questions/39282293/r-ggplot2-using-italics-and-non-italics-in-the-same-category-label

4. bactname OTUname name value
Staphylococcaceae OTU 1 Staphylococcaceae (OTU 1) -0.5
Moraxella OTU 2 Moraxella (OTU 2) 0.5
Streptococcus OTU 3 Streptococcus (OTU 3) 2.0
Acinetobacter OTU 4 Acinetobacter (OTU 4) 3.0

5. bactname OTUname name value
Staphylococcaceae OTU 1 Staphylococcaceae (OTU 1) -0.5
Moraxella OTU 2 Moraxella (OTU 2) 0.5
Streptococcus OTU 3 Streptococcus (OTU 3) 2.0
Acinetobacter OTU 4 Acinetobacter (OTU 4) 3.0
data %>%
ggplot(aes(name, value)) +
geom_col() + coord_flip()

6. bactname OTUname name value
Staphylococcaceae OTU 1 Staphylococcaceae (OTU 1) -0.5
Moraxella OTU 2 Moraxella (OTU 2) 0.5
Streptococcus OTU 3 Streptococcus (OTU 3) 2.0
Acinetobacter OTU 4 Acinetobacter (OTU 4) 3.0
data %>%
ggplot(aes(name, value)) +
geom_col() + coord_flip()

7. https://stackoverflow.com/questions/39282293/r-ggplot2-using-italics-and-non-italics-in-the-same-category-label

8. How should we specify formatted text?

9. data %>%
ggplot(aes(name, value)) +
geom_col() + coord_flip() +
ggtitle("species names are *in italics*")

10. data %>%
ggplot(aes(name, value)) +
geom_col() + coord_flip() +
ggtitle("species names are *in italics*")
library(ggtext) # remotes::install_github('wilkelab/ggtext')

11. data %>%
ggplot(aes(name, value)) +
geom_col() + coord_flip() +
ggtitle("species names are *in italics*") +
theme(plot.title = element_markdown())
library(ggtext) # remotes::install_github('wilkelab/ggtext')

12. data %>% mutate(
name = glue("*{bactname}* ({OTUname})") # library(glue)
)

13. data %>% mutate(
name = glue("*{bactname}* ({OTUname})") # library(glue)
)
bactname OTUname name value
Staphylococcaceae OTU 1 *Staphylococcaceae* (OTU 1) -0.5
Moraxella OTU 2 *Moraxella* (OTU 2) 0.5
Streptococcus OTU 3 *Streptococcus* (OTU 3) 2.0
Acinetobacter OTU 4 *Acinetobacter* (OTU 4) 3.0

14. data %>% mutate(
name = glue("*{bactname}* ({OTUname})")
) %>%
ggplot(aes(name, value)) +
geom_col() + coord_flip() +
theme(axis.text.y = element_markdown())

15. Your plots are boring.
Don’t you ever use color?

16. data %>% mutate(
color = c("#009E73", "#D55E00", "#0072B2", "#000000"),
name = glue("<i style='color:{color}'>{bactname}</i> ({OTUname})")
) %>%

17. data %>% mutate(
color = c("#009E73", "#D55E00", "#0072B2", "#000000"),
name = glue("<i style='color:{color}'>{bactname}</i> ({OTUname})")
) %>%
ggplot(aes(name, value, fill = color)) +
geom_col(alpha = 0.5) + coord_flip() +
scale_fill_identity() +
theme(axis.text.y = element_markdown())

18. What else can you do?

19. https://stackoverflow.com/questions/14070953/photo-
alignment-with-graph-in-r/30765590#30765590

20. labels <- c(
Interphase = "<img src='img/interphase.jpg' width='50' /><br>Interphase",
Prophase = "<img src='img/prophase.jpg' width='50' /><br>Prophase",
Metaphase = "<img src='img/metaphase.jpg' width='50' /><br>Metaphase",
Anaphase = "<img src='img/anaphase.jpg' width='50' /><br>Anaphase",
Telophase = "<img src='img/telophase.jpg' width='50' /><br>Telophase"
)
https://stackoverflow.com/questions/14070953/photo-
alignment-with-graph-in-r/30765590#30765590

21. https://stackoverflow.com/questions/14070953/photo-
alignment-with-graph-in-r/30765590#30765590
labels <- c(
Interphase = "<img src='img/interphase.jpg' width='50' /><br>Interphase",
...
)
ggplot(data, aes(phase, value, fill = cat)) +
geom_col(position = "dodge") +
scale_x_discrete(name = NULL, labels = labels) +
theme(axis.text.x = element_markdown(lineheight = 1.2))

22. https://stackoverflow.com/questions/14070953/photo-
alignment-with-graph-in-r/30765590#30765590
labels <- c(
Interphase = "<img src='img/interphase.jpg' width='50' /><br>Interphase",
...
)
ggplot(data, aes(phase, value, fill = cat)) +
geom_col(position = "dodge") +
scale_x_discrete(name = NULL, labels = labels) +
theme(axis.text.x = element_markdown(lineheight = 1.2))

23. Text boxes, backgrounds, and word-wrapping
https://wilkelab.org/ggtext

24. Does this only work for theme elements?

25. ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
geom_point() + geom_smooth(method = "lm") +
facet_wrap(~Species)

26. iris_cor <- iris %>%
group_by(Species) %>%
summarize(r_square = cor(Sepal.Length, Sepal.Width)^2)
iris_cor
#> # A tibble: 3 x 2
#> Species r_square
#> <fct> <dbl>
#> 1 setosa 0.551
#> 2 versicolor 0.277
#> 3 virginica 0.209

27. iris_cor <- iris %>%
group_by(Species) %>%
summarize(r_square = cor(Sepal.Length, Sepal.Width)^2) %>%
mutate(
Sepal.Length = 8,
Sepal.Width = 4.5,
label = glue("*r*² = {round(r_square, 2)}")
)
iris_cor
#> # A tibble: 3 x 5
#> Species r_square Sepal.Length Sepal.Width label
#> <fct> <dbl> <dbl> <dbl> <glue>
#> 1 setosa 0.551 8 4.5 *r*² = 0.55
#> 2 versicolor 0.277 8 4.5 *r*² = 0.28
#> 3 virginica 0.209 8 4.5 *r*² = 0.21

28. ggplot(iris, aes(Sepal.Length, Sepal.Width)) +
geom_point() + geom_smooth(method = "lm") +
geom_richtext(
data = iris_cor, aes(label = label),
hjust = 1, vjust = 1
) +
facet_wrap(~Species)

29. The package that makes it all possible

31. text <- "Some text **in bold.**"
gp <- grid::gpar(
fontfamily = "Comic Sans MS", fontsize = 20, col = "blue"
)
g1 <- grid::textGrob(text, 0.1, 0.7, hjust = 0, gp = gp)
grid::grid.draw(g1)

32. text <- "Some text **in bold.**"
gp <- grid::gpar(
fontfamily = "Comic Sans MS", fontsize = 20, col = "blue"
)
g1 <- grid::textGrob(text, 0.1, 0.7, hjust = 0, gp = gp)
g2 <- gridtext::richtext_grob(text, 0.1, 0.4, hjust = 0, gp = gp)
grid::grid.draw(g1)
grid::grid.draw(g2)

33. https://wilkelab.org/ggtext
https://wilkelab.org/gridtext
@clauswilke
clauswilke