Annotations: Drawing Attention to Parts of the Graph

Author

Arvind V.

Published

July 30, 2021

Modified

September 30, 2025

library(tidyverse)
library(ggformula)
library(systemfonts) ## use custom fonts (need to be installed on your OS)
library(scico) ## scico color palettes(http://www.fabiocrameri.ch/colourmaps.php) in R
library(ggtext) ## add improved text rendering to ggplot2
library(ggforce) ## add missing functionality to ggplot2
library(showtext) ## add google fonts to plots
library(ggrepel) ## repel overlapping text labels
library(marquee) ## add annotations with fonts to plots

1 Introduction

We may have been using ggplot2 for a while now, but there is always more to learn about the aesthetics of our plots. Here we will look at annotating our graphs and plots.

Annotations help to draw attention to specific parts or the graph, specific areas of interest that are useful in telling the story .

We have already seen the annotate() command from ggplot2 first ( and the new gf_annotate() from ggformula). Here we will look at some of the intrigung features from the ggforce package.

1.1 Fonts and Themes

As we learnt in the Fonts Module, let us set the ggplot theme with fonts for both the chart defining elements and our annotations. I am going to use local fonts from my machine, that I have downloaded from Google Fonts earlier and saved in a fonts folder at the root of my project.

Show the Code
## Clean the slate
systemfonts::clear_local_fonts()
systemfonts::clear_registry()
##
showtext_opts(dpi = 96) # set DPI for showtext
sysfonts::font_add(
  family = "Alegreya",
  regular = "../../../../../../fonts/Alegreya-Regular.ttf",
  bold = "../../../../../../fonts/Alegreya-Bold.ttf",
  italic = "../../../../../../fonts/Alegreya-Italic.ttf",
  bolditalic = "../../../../../../fonts/Alegreya-BoldItalic.ttf"
)

sysfonts::font_add(
  family = "Anton",
  regular = "../../../../../../fonts/Anton-Regular.ttf"
) # Only one style is available

sysfonts::font_add(
  family = "RobotoCondensed",
  regular = "../../../../../../fonts/RobotoCondensed-Regular.ttf",
  bold = "../../../../../../fonts/RobotoCondensed-Bold.ttf",
  italic = "../../../../../../fonts/RobotoCondensed-Italic.ttf",
  bolditalic = "../../../../../../fonts/RobotoCondensed-BoldItalic.ttf"
)

sysfonts::font_add(
  family = "IbarraNova",
  regular = "../../../../../../fonts/IbarraRealNova-Regular.ttf",
  bold = "../../../../../../fonts/IbarraRealNova-Bold.ttf",
  italic = "../../../../../../fonts/IbarraRealNova-Italic.ttf",
  bolditalic = "../../../../../../fonts/IbarraRealNova-BoldItalic.ttf"
)

sysfonts::font_add(
  family = "Tangerine",
  regular = "../../../../../../fonts/Tangerine-Regular.ttf",
  bold = "../../../../../../fonts/Tangerine-Bold.ttf"
) # only these two are available

sysfonts::font_add(
  family = "Schoolbell",
  regular = "../../../../../../fonts/Schoolbell-Regular.ttf"
) # Only regular is available

showtext_auto() # set these fonts as default for the session
sysfonts::font_families() # check which fonts are available in the session
 [1] "sans"            "serif"           "mono"            "wqy-microhei"   
 [5] "Alegreya"        "Anton"           "RobotoCondensed" "IbarraNova"     
 [9] "Tangerine"       "Schoolbell"
Show the Code
theme_custom <- function() {
  theme_bw(base_size = 10) +

    theme_sub_axis(
      title = element_text(
        family = "Roboto Condensed",
        size = 8
      ),
      text = element_text(
        family = "Roboto Condensed",
        size = 6
      )
    ) +

    theme_sub_legend(
      text = element_text(
        family = "Roboto Condensed",
        size = 6
      ),
      title = element_text(
        family = "Alegreya",
        size = 8
      )
    ) +

    theme_sub_plot(
      title = element_text(
        family = "Alegreya",
        size = 14, face = "bold"
      ),
      title.position = "plot",
      subtitle = element_text(
        family = "Alegreya",
        size = 10
      ),
      caption = element_text(
        family = "Alegreya",
        size = 6
      ),
      caption.position = "plot"
    )
}

## Set the theme
ggplot2::theme_set(new = theme_custom())



## Use available fonts in ggplot text geoms too!
ggplot2::update_geom_defaults(geom = "text", new = list(
  family = "Roboto Condensed",
  face = "plain",
  size = 3.5,
  color = "#2b2b2b"
))
ggplot2::update_geom_defaults(geom = "label", new = list(
  family = "Roboto Condensed",
  face = "plain",
  size = 3.5,
  color = "#2b2b2b"
))

ggplot2::update_geom_defaults(geom = "marquee", new = list(
  family = "Roboto Condensed",
  face = "plain",
  size = 3.5,
  color = "#2b2b2b"
))
ggplot2::update_geom_defaults(geom = "text_repel", new = list(
  family = "Roboto Condensed",
  face = "plain",
  size = 3.5,
  color = "#2b2b2b"
))
ggplot2::update_geom_defaults(geom = "label_repel", new = list(
  family = "Roboto Condensed",
  face = "plain",
  size = 3.5,
  color = "#2b2b2b"
))

## Set the theme
ggplot2::theme_set(new = theme_custom())

## tinytable options
options("tinytable_tt_digits" = 2)
options("tinytable_format_num_fmt" = "significant_cell")
options(tinytable_html_mathjax = TRUE)


## Set defaults for flextable
flextable::set_flextable_defaults(font.family = "Roboto Condensed")

2 Data

We will again work with a familiar dataset, so that we can concentrate on the chart aesthetics, without having to spend time getting used to the data: the penguins dataset again, from the palmerpenguins package now part of the R installation!.

As always, we will start with a table of the data:

penguins <- penguins %>% drop_na() # remove data containing missing data

## Create a nicely formatted table
## uses `kableExtra` package
##
penguins %>%
  kableExtra::kbl() %>%
  kableExtra::kable_paper(full_width = TRUE) %>%
  kableExtra::kable_styling(bootstrap_options = c("striped", "condensed", "responsive")) %>%
  kableExtra::scroll_box(width = "700px", height = "350px")
species island bill_len bill_dep flipper_len body_mass sex year
Adelie Torgersen 39.1 18.7 181 3750 male 2007
Adelie Torgersen 39.5 17.4 186 3800 female 2007
Adelie Torgersen 40.3 18.0 195 3250 female 2007
Adelie Torgersen 36.7 19.3 193 3450 female 2007
Adelie Torgersen 39.3 20.6 190 3650 male 2007
Adelie Torgersen 38.9 17.8 181 3625 female 2007
Adelie Torgersen 39.2 19.6 195 4675 male 2007
Adelie Torgersen 41.1 17.6 182 3200 female 2007
Adelie Torgersen 38.6 21.2 191 3800 male 2007
Adelie Torgersen 34.6 21.1 198 4400 male 2007
Adelie Torgersen 36.6 17.8 185 3700 female 2007
Adelie Torgersen 38.7 19.0 195 3450 female 2007
Adelie Torgersen 42.5 20.7 197 4500 male 2007
Adelie Torgersen 34.4 18.4 184 3325 female 2007
Adelie Torgersen 46.0 21.5 194 4200 male 2007
Adelie Biscoe 37.8 18.3 174 3400 female 2007
Adelie Biscoe 37.7 18.7 180 3600 male 2007
Adelie Biscoe 35.9 19.2 189 3800 female 2007
Adelie Biscoe 38.2 18.1 185 3950 male 2007
Adelie Biscoe 38.8 17.2 180 3800 male 2007
Adelie Biscoe 35.3 18.9 187 3800 female 2007
Adelie Biscoe 40.6 18.6 183 3550 male 2007
Adelie Biscoe 40.5 17.9 187 3200 female 2007
Adelie Biscoe 37.9 18.6 172 3150 female 2007
Adelie Biscoe 40.5 18.9 180 3950 male 2007
Adelie Dream 39.5 16.7 178 3250 female 2007
Adelie Dream 37.2 18.1 178 3900 male 2007
Adelie Dream 39.5 17.8 188 3300 female 2007
Adelie Dream 40.9 18.9 184 3900 male 2007
Adelie Dream 36.4 17.0 195 3325 female 2007
Adelie Dream 39.2 21.1 196 4150 male 2007
Adelie Dream 38.8 20.0 190 3950 male 2007
Adelie Dream 42.2 18.5 180 3550 female 2007
Adelie Dream 37.6 19.3 181 3300 female 2007
Adelie Dream 39.8 19.1 184 4650 male 2007
Adelie Dream 36.5 18.0 182 3150 female 2007
Adelie Dream 40.8 18.4 195 3900 male 2007
Adelie Dream 36.0 18.5 186 3100 female 2007
Adelie Dream 44.1 19.7 196 4400 male 2007
Adelie Dream 37.0 16.9 185 3000 female 2007
Adelie Dream 39.6 18.8 190 4600 male 2007
Adelie Dream 41.1 19.0 182 3425 male 2007
Adelie Dream 36.0 17.9 190 3450 female 2007
Adelie Dream 42.3 21.2 191 4150 male 2007
Adelie Biscoe 39.6 17.7 186 3500 female 2008
Adelie Biscoe 40.1 18.9 188 4300 male 2008
Adelie Biscoe 35.0 17.9 190 3450 female 2008
Adelie Biscoe 42.0 19.5 200 4050 male 2008
Adelie Biscoe 34.5 18.1 187 2900 female 2008
Adelie Biscoe 41.4 18.6 191 3700 male 2008
Adelie Biscoe 39.0 17.5 186 3550 female 2008
Adelie Biscoe 40.6 18.8 193 3800 male 2008
Adelie Biscoe 36.5 16.6 181 2850 female 2008
Adelie Biscoe 37.6 19.1 194 3750 male 2008
Adelie Biscoe 35.7 16.9 185 3150 female 2008
Adelie Biscoe 41.3 21.1 195 4400 male 2008
Adelie Biscoe 37.6 17.0 185 3600 female 2008
Adelie Biscoe 41.1 18.2 192 4050 male 2008
Adelie Biscoe 36.4 17.1 184 2850 female 2008
Adelie Biscoe 41.6 18.0 192 3950 male 2008
Adelie Biscoe 35.5 16.2 195 3350 female 2008
Adelie Biscoe 41.1 19.1 188 4100 male 2008
Adelie Torgersen 35.9 16.6 190 3050 female 2008
Adelie Torgersen 41.8 19.4 198 4450 male 2008
Adelie Torgersen 33.5 19.0 190 3600 female 2008
Adelie Torgersen 39.7 18.4 190 3900 male 2008
Adelie Torgersen 39.6 17.2 196 3550 female 2008
Adelie Torgersen 45.8 18.9 197 4150 male 2008
Adelie Torgersen 35.5 17.5 190 3700 female 2008
Adelie Torgersen 42.8 18.5 195 4250 male 2008
Adelie Torgersen 40.9 16.8 191 3700 female 2008
Adelie Torgersen 37.2 19.4 184 3900 male 2008
Adelie Torgersen 36.2 16.1 187 3550 female 2008
Adelie Torgersen 42.1 19.1 195 4000 male 2008
Adelie Torgersen 34.6 17.2 189 3200 female 2008
Adelie Torgersen 42.9 17.6 196 4700 male 2008
Adelie Torgersen 36.7 18.8 187 3800 female 2008
Adelie Torgersen 35.1 19.4 193 4200 male 2008
Adelie Dream 37.3 17.8 191 3350 female 2008
Adelie Dream 41.3 20.3 194 3550 male 2008
Adelie Dream 36.3 19.5 190 3800 male 2008
Adelie Dream 36.9 18.6 189 3500 female 2008
Adelie Dream 38.3 19.2 189 3950 male 2008
Adelie Dream 38.9 18.8 190 3600 female 2008
Adelie Dream 35.7 18.0 202 3550 female 2008
Adelie Dream 41.1 18.1 205 4300 male 2008
Adelie Dream 34.0 17.1 185 3400 female 2008
Adelie Dream 39.6 18.1 186 4450 male 2008
Adelie Dream 36.2 17.3 187 3300 female 2008
Adelie Dream 40.8 18.9 208 4300 male 2008
Adelie Dream 38.1 18.6 190 3700 female 2008
Adelie Dream 40.3 18.5 196 4350 male 2008
Adelie Dream 33.1 16.1 178 2900 female 2008
Adelie Dream 43.2 18.5 192 4100 male 2008
Adelie Biscoe 35.0 17.9 192 3725 female 2009
Adelie Biscoe 41.0 20.0 203 4725 male 2009
Adelie Biscoe 37.7 16.0 183 3075 female 2009
Adelie Biscoe 37.8 20.0 190 4250 male 2009
Adelie Biscoe 37.9 18.6 193 2925 female 2009
Adelie Biscoe 39.7 18.9 184 3550 male 2009
Adelie Biscoe 38.6 17.2 199 3750 female 2009
Adelie Biscoe 38.2 20.0 190 3900 male 2009
Adelie Biscoe 38.1 17.0 181 3175 female 2009
Adelie Biscoe 43.2 19.0 197 4775 male 2009
Adelie Biscoe 38.1 16.5 198 3825 female 2009
Adelie Biscoe 45.6 20.3 191 4600 male 2009
Adelie Biscoe 39.7 17.7 193 3200 female 2009
Adelie Biscoe 42.2 19.5 197 4275 male 2009
Adelie Biscoe 39.6 20.7 191 3900 female 2009
Adelie Biscoe 42.7 18.3 196 4075 male 2009
Adelie Torgersen 38.6 17.0 188 2900 female 2009
Adelie Torgersen 37.3 20.5 199 3775 male 2009
Adelie Torgersen 35.7 17.0 189 3350 female 2009
Adelie Torgersen 41.1 18.6 189 3325 male 2009
Adelie Torgersen 36.2 17.2 187 3150 female 2009
Adelie Torgersen 37.7 19.8 198 3500 male 2009
Adelie Torgersen 40.2 17.0 176 3450 female 2009
Adelie Torgersen 41.4 18.5 202 3875 male 2009
Adelie Torgersen 35.2 15.9 186 3050 female 2009
Adelie Torgersen 40.6 19.0 199 4000 male 2009
Adelie Torgersen 38.8 17.6 191 3275 female 2009
Adelie Torgersen 41.5 18.3 195 4300 male 2009
Adelie Torgersen 39.0 17.1 191 3050 female 2009
Adelie Torgersen 44.1 18.0 210 4000 male 2009
Adelie Torgersen 38.5 17.9 190 3325 female 2009
Adelie Torgersen 43.1 19.2 197 3500 male 2009
Adelie Dream 36.8 18.5 193 3500 female 2009
Adelie Dream 37.5 18.5 199 4475 male 2009
Adelie Dream 38.1 17.6 187 3425 female 2009
Adelie Dream 41.1 17.5 190 3900 male 2009
Adelie Dream 35.6 17.5 191 3175 female 2009
Adelie Dream 40.2 20.1 200 3975 male 2009
Adelie Dream 37.0 16.5 185 3400 female 2009
Adelie Dream 39.7 17.9 193 4250 male 2009
Adelie Dream 40.2 17.1 193 3400 female 2009
Adelie Dream 40.6 17.2 187 3475 male 2009
Adelie Dream 32.1 15.5 188 3050 female 2009
Adelie Dream 40.7 17.0 190 3725 male 2009
Adelie Dream 37.3 16.8 192 3000 female 2009
Adelie Dream 39.0 18.7 185 3650 male 2009
Adelie Dream 39.2 18.6 190 4250 male 2009
Adelie Dream 36.6 18.4 184 3475 female 2009
Adelie Dream 36.0 17.8 195 3450 female 2009
Adelie Dream 37.8 18.1 193 3750 male 2009
Adelie Dream 36.0 17.1 187 3700 female 2009
Adelie Dream 41.5 18.5 201 4000 male 2009
Gentoo Biscoe 46.1 13.2 211 4500 female 2007
Gentoo Biscoe 50.0 16.3 230 5700 male 2007
Gentoo Biscoe 48.7 14.1 210 4450 female 2007
Gentoo Biscoe 50.0 15.2 218 5700 male 2007
Gentoo Biscoe 47.6 14.5 215 5400 male 2007
Gentoo Biscoe 46.5 13.5 210 4550 female 2007
Gentoo Biscoe 45.4 14.6 211 4800 female 2007
Gentoo Biscoe 46.7 15.3 219 5200 male 2007
Gentoo Biscoe 43.3 13.4 209 4400 female 2007
Gentoo Biscoe 46.8 15.4 215 5150 male 2007
Gentoo Biscoe 40.9 13.7 214 4650 female 2007
Gentoo Biscoe 49.0 16.1 216 5550 male 2007
Gentoo Biscoe 45.5 13.7 214 4650 female 2007
Gentoo Biscoe 48.4 14.6 213 5850 male 2007
Gentoo Biscoe 45.8 14.6 210 4200 female 2007
Gentoo Biscoe 49.3 15.7 217 5850 male 2007
Gentoo Biscoe 42.0 13.5 210 4150 female 2007
Gentoo Biscoe 49.2 15.2 221 6300 male 2007
Gentoo Biscoe 46.2 14.5 209 4800 female 2007
Gentoo Biscoe 48.7 15.1 222 5350 male 2007
Gentoo Biscoe 50.2 14.3 218 5700 male 2007
Gentoo Biscoe 45.1 14.5 215 5000 female 2007
Gentoo Biscoe 46.5 14.5 213 4400 female 2007
Gentoo Biscoe 46.3 15.8 215 5050 male 2007
Gentoo Biscoe 42.9 13.1 215 5000 female 2007
Gentoo Biscoe 46.1 15.1 215 5100 male 2007
Gentoo Biscoe 47.8 15.0 215 5650 male 2007
Gentoo Biscoe 48.2 14.3 210 4600 female 2007
Gentoo Biscoe 50.0 15.3 220 5550 male 2007
Gentoo Biscoe 47.3 15.3 222 5250 male 2007
Gentoo Biscoe 42.8 14.2 209 4700 female 2007
Gentoo Biscoe 45.1 14.5 207 5050 female 2007
Gentoo Biscoe 59.6 17.0 230 6050 male 2007
Gentoo Biscoe 49.1 14.8 220 5150 female 2008
Gentoo Biscoe 48.4 16.3 220 5400 male 2008
Gentoo Biscoe 42.6 13.7 213 4950 female 2008
Gentoo Biscoe 44.4 17.3 219 5250 male 2008
Gentoo Biscoe 44.0 13.6 208 4350 female 2008
Gentoo Biscoe 48.7 15.7 208 5350 male 2008
Gentoo Biscoe 42.7 13.7 208 3950 female 2008
Gentoo Biscoe 49.6 16.0 225 5700 male 2008
Gentoo Biscoe 45.3 13.7 210 4300 female 2008
Gentoo Biscoe 49.6 15.0 216 4750 male 2008
Gentoo Biscoe 50.5 15.9 222 5550 male 2008
Gentoo Biscoe 43.6 13.9 217 4900 female 2008
Gentoo Biscoe 45.5 13.9 210 4200 female 2008
Gentoo Biscoe 50.5 15.9 225 5400 male 2008
Gentoo Biscoe 44.9 13.3 213 5100 female 2008
Gentoo Biscoe 45.2 15.8 215 5300 male 2008
Gentoo Biscoe 46.6 14.2 210 4850 female 2008
Gentoo Biscoe 48.5 14.1 220 5300 male 2008
Gentoo Biscoe 45.1 14.4 210 4400 female 2008
Gentoo Biscoe 50.1 15.0 225 5000 male 2008
Gentoo Biscoe 46.5 14.4 217 4900 female 2008
Gentoo Biscoe 45.0 15.4 220 5050 male 2008
Gentoo Biscoe 43.8 13.9 208 4300 female 2008
Gentoo Biscoe 45.5 15.0 220 5000 male 2008
Gentoo Biscoe 43.2 14.5 208 4450 female 2008
Gentoo Biscoe 50.4 15.3 224 5550 male 2008
Gentoo Biscoe 45.3 13.8 208 4200 female 2008
Gentoo Biscoe 46.2 14.9 221 5300 male 2008
Gentoo Biscoe 45.7 13.9 214 4400 female 2008
Gentoo Biscoe 54.3 15.7 231 5650 male 2008
Gentoo Biscoe 45.8 14.2 219 4700 female 2008
Gentoo Biscoe 49.8 16.8 230 5700 male 2008
Gentoo Biscoe 49.5 16.2 229 5800 male 2008
Gentoo Biscoe 43.5 14.2 220 4700 female 2008
Gentoo Biscoe 50.7 15.0 223 5550 male 2008
Gentoo Biscoe 47.7 15.0 216 4750 female 2008
Gentoo Biscoe 46.4 15.6 221 5000 male 2008
Gentoo Biscoe 48.2 15.6 221 5100 male 2008
Gentoo Biscoe 46.5 14.8 217 5200 female 2008
Gentoo Biscoe 46.4 15.0 216 4700 female 2008
Gentoo Biscoe 48.6 16.0 230 5800 male 2008
Gentoo Biscoe 47.5 14.2 209 4600 female 2008
Gentoo Biscoe 51.1 16.3 220 6000 male 2008
Gentoo Biscoe 45.2 13.8 215 4750 female 2008
Gentoo Biscoe 45.2 16.4 223 5950 male 2008
Gentoo Biscoe 49.1 14.5 212 4625 female 2009
Gentoo Biscoe 52.5 15.6 221 5450 male 2009
Gentoo Biscoe 47.4 14.6 212 4725 female 2009
Gentoo Biscoe 50.0 15.9 224 5350 male 2009
Gentoo Biscoe 44.9 13.8 212 4750 female 2009
Gentoo Biscoe 50.8 17.3 228 5600 male 2009
Gentoo Biscoe 43.4 14.4 218 4600 female 2009
Gentoo Biscoe 51.3 14.2 218 5300 male 2009
Gentoo Biscoe 47.5 14.0 212 4875 female 2009
Gentoo Biscoe 52.1 17.0 230 5550 male 2009
Gentoo Biscoe 47.5 15.0 218 4950 female 2009
Gentoo Biscoe 52.2 17.1 228 5400 male 2009
Gentoo Biscoe 45.5 14.5 212 4750 female 2009
Gentoo Biscoe 49.5 16.1 224 5650 male 2009
Gentoo Biscoe 44.5 14.7 214 4850 female 2009
Gentoo Biscoe 50.8 15.7 226 5200 male 2009
Gentoo Biscoe 49.4 15.8 216 4925 male 2009
Gentoo Biscoe 46.9 14.6 222 4875 female 2009
Gentoo Biscoe 48.4 14.4 203 4625 female 2009
Gentoo Biscoe 51.1 16.5 225 5250 male 2009
Gentoo Biscoe 48.5 15.0 219 4850 female 2009
Gentoo Biscoe 55.9 17.0 228 5600 male 2009
Gentoo Biscoe 47.2 15.5 215 4975 female 2009
Gentoo Biscoe 49.1 15.0 228 5500 male 2009
Gentoo Biscoe 46.8 16.1 215 5500 male 2009
Gentoo Biscoe 41.7 14.7 210 4700 female 2009
Gentoo Biscoe 53.4 15.8 219 5500 male 2009
Gentoo Biscoe 43.3 14.0 208 4575 female 2009
Gentoo Biscoe 48.1 15.1 209 5500 male 2009
Gentoo Biscoe 50.5 15.2 216 5000 female 2009
Gentoo Biscoe 49.8 15.9 229 5950 male 2009
Gentoo Biscoe 43.5 15.2 213 4650 female 2009
Gentoo Biscoe 51.5 16.3 230 5500 male 2009
Gentoo Biscoe 46.2 14.1 217 4375 female 2009
Gentoo Biscoe 55.1 16.0 230 5850 male 2009
Gentoo Biscoe 48.8 16.2 222 6000 male 2009
Gentoo Biscoe 47.2 13.7 214 4925 female 2009
Gentoo Biscoe 46.8 14.3 215 4850 female 2009
Gentoo Biscoe 50.4 15.7 222 5750 male 2009
Gentoo Biscoe 45.2 14.8 212 5200 female 2009
Gentoo Biscoe 49.9 16.1 213 5400 male 2009
Chinstrap Dream 46.5 17.9 192 3500 female 2007
Chinstrap Dream 50.0 19.5 196 3900 male 2007
Chinstrap Dream 51.3 19.2 193 3650 male 2007
Chinstrap Dream 45.4 18.7 188 3525 female 2007
Chinstrap Dream 52.7 19.8 197 3725 male 2007
Chinstrap Dream 45.2 17.8 198 3950 female 2007
Chinstrap Dream 46.1 18.2 178 3250 female 2007
Chinstrap Dream 51.3 18.2 197 3750 male 2007
Chinstrap Dream 46.0 18.9 195 4150 female 2007
Chinstrap Dream 51.3 19.9 198 3700 male 2007
Chinstrap Dream 46.6 17.8 193 3800 female 2007
Chinstrap Dream 51.7 20.3 194 3775 male 2007
Chinstrap Dream 47.0 17.3 185 3700 female 2007
Chinstrap Dream 52.0 18.1 201 4050 male 2007
Chinstrap Dream 45.9 17.1 190 3575 female 2007
Chinstrap Dream 50.5 19.6 201 4050 male 2007
Chinstrap Dream 50.3 20.0 197 3300 male 2007
Chinstrap Dream 58.0 17.8 181 3700 female 2007
Chinstrap Dream 46.4 18.6 190 3450 female 2007
Chinstrap Dream 49.2 18.2 195 4400 male 2007
Chinstrap Dream 42.4 17.3 181 3600 female 2007
Chinstrap Dream 48.5 17.5 191 3400 male 2007
Chinstrap Dream 43.2 16.6 187 2900 female 2007
Chinstrap Dream 50.6 19.4 193 3800 male 2007
Chinstrap Dream 46.7 17.9 195 3300 female 2007
Chinstrap Dream 52.0 19.0 197 4150 male 2007
Chinstrap Dream 50.5 18.4 200 3400 female 2008
Chinstrap Dream 49.5 19.0 200 3800 male 2008
Chinstrap Dream 46.4 17.8 191 3700 female 2008
Chinstrap Dream 52.8 20.0 205 4550 male 2008
Chinstrap Dream 40.9 16.6 187 3200 female 2008
Chinstrap Dream 54.2 20.8 201 4300 male 2008
Chinstrap Dream 42.5 16.7 187 3350 female 2008
Chinstrap Dream 51.0 18.8 203 4100 male 2008
Chinstrap Dream 49.7 18.6 195 3600 male 2008
Chinstrap Dream 47.5 16.8 199 3900 female 2008
Chinstrap Dream 47.6 18.3 195 3850 female 2008
Chinstrap Dream 52.0 20.7 210 4800 male 2008
Chinstrap Dream 46.9 16.6 192 2700 female 2008
Chinstrap Dream 53.5 19.9 205 4500 male 2008
Chinstrap Dream 49.0 19.5 210 3950 male 2008
Chinstrap Dream 46.2 17.5 187 3650 female 2008
Chinstrap Dream 50.9 19.1 196 3550 male 2008
Chinstrap Dream 45.5 17.0 196 3500 female 2008
Chinstrap Dream 50.9 17.9 196 3675 female 2009
Chinstrap Dream 50.8 18.5 201 4450 male 2009
Chinstrap Dream 50.1 17.9 190 3400 female 2009
Chinstrap Dream 49.0 19.6 212 4300 male 2009
Chinstrap Dream 51.5 18.7 187 3250 male 2009
Chinstrap Dream 49.8 17.3 198 3675 female 2009
Chinstrap Dream 48.1 16.4 199 3325 female 2009
Chinstrap Dream 51.4 19.0 201 3950 male 2009
Chinstrap Dream 45.7 17.3 193 3600 female 2009
Chinstrap Dream 50.7 19.7 203 4050 male 2009
Chinstrap Dream 42.5 17.3 187 3350 female 2009
Chinstrap Dream 52.2 18.8 197 3450 male 2009
Chinstrap Dream 45.2 16.6 191 3250 female 2009
Chinstrap Dream 49.3 19.9 203 4050 male 2009
Chinstrap Dream 50.2 18.8 202 3800 male 2009
Chinstrap Dream 45.6 19.4 194 3525 female 2009
Chinstrap Dream 51.9 19.5 206 3950 male 2009
Chinstrap Dream 46.8 16.5 189 3650 female 2009
Chinstrap Dream 45.7 17.0 195 3650 female 2009
Chinstrap Dream 55.8 19.8 207 4000 male 2009
Chinstrap Dream 43.5 18.1 202 3400 female 2009
Chinstrap Dream 49.6 18.2 193 3775 male 2009
Chinstrap Dream 50.8 19.0 210 4100 male 2009
Chinstrap Dream 50.2 18.7 198 3775 female 2009
Table 1: Penguins Dataset

3 Basic Plot

A basic scatter plot, which we will use to highlight and draw attention to specific areas of the plot. We will include, for the sake of retaining context, the fonts and labels that we have used in previous modules. And we will also use ggtext to format the axis titles and the plot title.

Show the Code
p1 <- gf_point(
  data = penguins, bill_dep ~ bill_len,
  color = ~body_mass, alpha = 0.8, size = 3.5
) %>%
  ## custom colors from the scico package
  gf_refine(scico::scale_color_scico(palette = "tokyo", direction = -1)) %>%
  ## custom labels
  gf_labs(
    title = "Bill Dimensions of Brush-Tailed Penguins (**Pygoscelis**)",
    subtitle = "A scatter plot of bill depth versus bill length.",
    caption = "Data: Gorman, Williams & Fraser (2014) PLoS ONE",
    x = "**Bill Length** (mm)",
    y = "**Bill Depth** (mm)",
    color = "Body mass (g)"
  ) %>%
  ## 2. Add theme related commands from ggtext
  ## render respective text elements
  gf_theme(theme(
    plot.title = ggtext::element_markdown(),
    plot.caption = ggtext::element_markdown(),
    axis.title.x = ggtext::element_markdown(),
    axis.title.y = ggtext::element_markdown()
  ))


p1

4 Using {ggforce}

From Thomas Lin Pedersen’s website → www.ggforce.data-imaginist.com

ggforce is a package aimed at providing missing functionality to ggplot2 through the extension system introduced with ggplot2 v2.0.0. Broadly speaking ggplot2 has been aimed primarily at explorative data visualization in order to investigate the data at hand, and less at providing utilities for composing custom plots a la D3.js. ggforce is mainly an attempt to address these “shortcoming” (design choices might be a better description). The goal is to provide a repository of geoms, stats, etc. that are as well documented and implemented as the official ones found in ggplot2.

We will start with the basic plot, with the fonts, labels and ggtext related work done up to now: First, let us update the theme to use the ggtext options, and then we will add the ggforce annotations.

4.1 Using ellipses

## ellipsoids for all groups
p1 +
  # penguins data is inherited automatically
  # Can use other data also if needed
  ggforce::geom_mark_ellipse(
    aes(
      fill = species,
      label = species
    ),
    alpha = .15,
    show.legend = FALSE
  ) +

  # Repeat the points!
  # Why? So the ellipses don't hide them!
  geom_point(aes(color = body_mass),
    alpha = .6,
    size = 3.5
  )

4.2 Highlighting one group

Add an Ellipse

## ellipsoids for specific subset
p1 +
  ggforce::geom_mark_ellipse(
    aes(
      fill = species,
      label = species,
      filter = species == "Gentoo"
    ), # Very Curious syntax here!!
    alpha = 0.25,
    show.legend = FALSE
  ) +
  geom_point(aes(color = body_mass),
    alpha = .6,
    size = 3.5
  )

Adding Circles

## circles
p1 +
  ggforce::geom_mark_circle(
    aes(
      fill = species, label = species,
      filter = species == "Gentoo"
    ),
    alpha = 0.25,
    show.legend = FALSE
  ) +
  geom_point(aes(color = body_mass),
    alpha = .6,
    size = 3.5
  )

Adding Rectangles

## rectangles
p1 +
  ggforce::geom_mark_rect(
    aes(
      fill = species,
      label = species,
      filter = species == "Gentoo"
    ),
    alpha = 0.25,
    show.legend = FALSE
  ) +
  geom_point(aes(color = body_mass),
    alpha = .6,
    size = 3.5
  )

Adding a Convex Hull

library(concaveman)
## hull
p1 +
  ggforce::geom_mark_hull(
    aes(
      fill = species,
      label = species,
      filter = species == "Gentoo"
    ),
    alpha = 0.25,
    show.legend = FALSE
  ) +
  geom_point(aes(color = body_mass),
    alpha = .6,
    size = 3.5
  )

R Package Citations
Package Version Citation
fpp3 1.0.2 Hyndman (2025)
gghighlight 0.5.0 Yutani (2025)
timetk 2.9.1 Dancho and Vaughan (2025)
tsbox 0.4.2 Sax (2021)
tsdl 0.1.0 Hyndman and Yang (2025)
tsibble 1.1.6 Wang, Cook, and Hyndman (2020)
tsibbledata 0.4.1 O’Hara-Wild et al. (2022)
TSstudio 0.1.7 Krispin (2023)
Dancho, Matt, and Davis Vaughan. 2025. timetk: A Tool Kit for Working with Time Series. https://doi.org/10.32614/CRAN.package.timetk.
Hyndman, Rob. 2025. Fpp3: Data for “Forecasting: Principles and Practice” (3rd Edition). https://doi.org/10.32614/CRAN.package.fpp3.
Hyndman, Rob, and Yangzhuoran Yang. 2025. tsdl: Time Series Data Library. https://github.com/FinYang/tsdl.
Krispin, Rami. 2023. TSstudio: Functions for Time Series Analysis and Forecasting. https://doi.org/10.32614/CRAN.package.TSstudio.
O’Hara-Wild, Mitchell, Rob Hyndman, Earo Wang, and Rakshitha Godahewa. 2022. tsibbledata: Diverse Datasets for “tsibble”. https://doi.org/10.32614/CRAN.package.tsibbledata.
Sax, Christoph. 2021. tsbox: Class-Agnostic Time Series in in R. https://docs.ropensci.org/tsbox/.
Wang, Earo, Dianne Cook, and Rob J Hyndman. 2020. “A New Tidy Data Structure to Support Exploration and Modeling of Temporal Data.” Journal of Computational and Graphical Statistics 29 (3): 466–78. https://doi.org/10.1080/10618600.2019.1695624.
Yutani, Hiroaki. 2025. gghighlight: Highlight Lines and Points in “ggplot2”. https://doi.org/10.32614/CRAN.package.gghighlight.
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