TidyTuesday Week 33: Scott

A Munro is a Scottish mountain with an elevation of over 3,000 feet, whereas a Munro Top is a subsidiary summit of a Munro that also exceeds 3,000 feet in height but is not considered a distinct mountain in its own right. The most famous Munro is Ben Nevis.

Change in Munro Status :::

1. R code

# Load the packages in ----------------------------------------------------

if (!require(tidyverse)) {
  install.packages("tidyverse")
  library(tidyverse)
}
if (!require(patchwork)) {
  install.packages("patchwork")
  library(patchwork)
}
if (!require(ggplot2)) {
  install.packages("ggplot2")
  library(ggplot2)
}
if (!require(ggalluvial)) {
  install.packages("ggalluvial")
  library(ggalluvial)
}
if (!require(scales)) {
  install.packages("scales")
  library(scales)
}
if (!require(RColorBrewer)) {
  install.packages("RColorBrewer")
  library(RColorBrewer)
}
# I stick all my styling into a CUsotm PAckage to tidy up my code and keep it consistent over the time
if (!require(CustomGGPlot2Theme)) {
  devtools::install("CustomGGPlot2Theme")
  library(CustomGGPlot2Theme)
}


scottish_munros <- readr::read_csv(
  'https://raw.githubusercontent.com/rfordatascience/tidytuesday/main/data/2025/2025-08-19/scottish_munros.csv'
)


munros_long <- scottish_munros |>
  pivot_longer(
    cols = `1891`:`2021`,
    names_to = "Year",
    values_to = "Classification"
  )

duplicate <- munros_long |>
  filter(!is.na(Classification)) |>
  group_by(Name) |>
  summarise(n = n_distinct(Classification)) |>
  filter(n >= 2)

munros_clean <- munros_long |>
  filter(Name %in% duplicate$Name) |>
  filter(!is.na(Classification)) |>
  arrange(Name, Year) |>
  group_by(Name, Year) |>
  slice(1) |>
  ungroup() |>
  mutate(Year = factor(Year, levels = sort(unique(Year))))

numbers <- munros_clean |>
  group_by(Year, Classification) |>
  summarise(n = n(), .groups = "drop") |>
  group_by(Year) |>
  mutate(pct = n / sum(n) * 100, y = 60 / 2)

title = "Alluvial Plot of Scottish Munro classifications that have changed over the years"

p1 <- ggplot(
  munros_clean,
  aes(
    x = Year,
    stratum = Classification,
    alluvium = Name,
    fill = Classification
  )
) +
  geom_flow(stat = "alluvium") +
  geom_stratum() +
  geom_text(
    data = numbers,
    aes(
      x = Year,
      y = y,
      stratum = Classification,
      label = paste0(n, "\n", round(pct, digits = 0), "%")
    ),
    stat = "stratum",
    inherit.aes = F,
    size = 4,
    color = "black"
  ) +
  Custom_Style() +
  theme(
    legend.title = element_blank(),
    axis.ticks.y = element_blank(),
    axis.title.y = element_text(
      margin = margin(r = 15)
    ),
    legend.key.height = unit(1, "cm"),
    legend.key.width = unit(0.5, "cm")
  ) +
  guides(fill = guide_legend(nrow = 2)) +
  labs(title = str_wrap(title, 40), y = "Number of Scottish Munros")