Comparison bars: Bar plot with shifted positions, facilitating comparisons (originally posted by https://bsky.app/profile/hrbrmstr.dev/post/3lik7thxdmc2m)

gistfile1.txt

library(ggplot2)
library(hrbrthemes)
library(janitor)

read.csv(text='"Party","Votes in all of the U.K.","Votes only in Scotland"
"Labour",33.7,35.27801359
"Conservative",23.7,12.72746096
"Reform UK",14.3,6.956199453
"Liberal\nDemocrats",12.2,9.699645107
"Greens",6.7,3.838190168
"Scottish\nNational\nParty",2.5,30.0130445
"Others",6.8,1.487446217
', header=TRUE) |> 
  janitor::clean_names() |> 
  transform(
    votes_in_all_of_the_u_k = votes_in_all_of_the_u_k/100,
    votes_only_in_scotland = votes_only_in_scotland/100,
    party = factor(party, party)
  ) -> xdf

c(
  "Labour" = "#dc2c2b",
  "Conservative" = "#013b83",
  "Reform UK" = "#1888a0",
  "Liberal\nDemocrats" = "#b15501",
  "Greens" = "#337f27",
  "Scottish\nNational\nParty" = "#cc9800",
  "Others" = "#a2a2a2"
) -> party_cols

ggplot() +
  geom_col(
    data = xdf,
    aes(party, votes_only_in_scotland, fill = party, alpha = "Votes only in Scotland"),
    position = position_nudge(-0.125),
    width = 0.5
  ) +
  geom_col(
    data = xdf,
    aes(party, votes_in_all_of_the_u_k, fill = party, alpha = "Votes in all of the U.K."),
    position = position_nudge(0.125),
    width = 0.5
  ) +
  geom_text(
    data = xdf,
    aes(party, votes_in_all_of_the_u_k + 0.015, label = scales::percent(votes_in_all_of_the_u_k, 0.1)),
    position = position_nudge(0.125),
    family = font_gs,
    size = 3,
    color = "black",
    fontface = "bold"
  ) + 
  geom_text(
    data = xdf |> subset(party %in% c("Labour", "Scottish\nNational\nParty")),
    aes(party, votes_only_in_scotland + 0.015, label = scales::percent(votes_only_in_scotland, 0.1)),
    position = position_nudge(-0.125),
    family = font_gs,
    size = 3
  ) +
  geom_text(
    data = data.frame(
      x = "Scottish\nNational\nParty", 
      y = 0.3,
      label = "\n← 30% of Scots\nvoted for the SNP,\nleading to 2.5% total\nU.K. votes."
    ),
    aes(
      x, y, label = label
    ),
    family = font_gs,
    size = 3,
    hjust = 0,
    vjust = "top",
    lineheight = 0.975,
    position = position_nudge(0.18)
  ) +
  scale_alpha_manual(
    name = NULL,
    values =  c(
      "Votes only in Scotland" = 1/2,
      "Votes in all of the U.K." = 1
    )
  ) +
  scale_fill_manual(
    values = party_cols,
  ) +
  scale_y_continuous(
    labels = scales::percent_format(),
    breaks = c(0.1, 0.2, 0.3),
    expand = c(0, 0, 0, 0),
    limit = c(0, 0.4)
  ) +
  guides(
    alpha = guide_legend(
      reverse = TRUE,
      override.aes = list(
        fill = "black"
      ),
      theme = theme(
        legend.direction = "horizontal",
        legend.key.width = unit(14, "pt"),
        legend.key.height = unit(14, "pt")
      )
    ),
    fill = "none"
  ) +
  labs(
    x = NULL, y = NULL,
    title = "U.K. election results 2024"
  ) +
  theme_ipsum_gs(grid="Y") +
  theme(
    axis.line.x.bottom = element_line(color = "black"),
    axis.text.x.bottom = element_text(margin = margin(t = 5)),
    legend.justification = "left",
    legend.position = "top",
    legend.location = "plot",
    legend.margin = margin(l = 0),
    plot.title.position = "plot"
  )