Chernoff faces

R code of the ggplot2 example

library(ggplot2)
library(dplyr)
library(gapminder)
library(ggChernoff)

## One face per continent and year: the smile codes the median life
## expectancy, the space between the eyes the median GDP per capita.
faces <- gapminder |>
  filter(year %in% c(1952, 1977, 2007)) |>
  group_by(continent, year) |>
  summarise(life = median(lifeExp), gdp = log10(median(gdpPercap)), .groups = "drop")

p <- ggplot(faces, aes(x = factor(year), y = continent, smile = life, eyes = gdp, fill = continent)) +
  geom_chernoff(size = 24, colour = "#262626") +
  scale_fill_manual(values = continent_colors, guide = "none") +
  scale_y_discrete(limits = rev) +
  scale_smile_continuous(range = c(-1, 1), guide = "none") +
  scale_eyes_continuous(guide = "none") +
  labs(title = "Median life expectancy rose on every continent",
       subtitle = "Medians by continent: the wider the smile, the longer the life expectancy; the wider apart the eyes, the higher the GDP per capita",
       x = NULL, y = NULL,
       caption = "Data: Gapminder, via the gapminder R package") +
  theme_lex_viz(grid = "", arrows = "")