Create an animated GIF of European urban population 1500-1800

europop.R

library(devtools)

install_github("mdlincoln/europop")

library(europop)
library(dplyr)
library(rgdal)
library(ggplot2)
library(animation)

# Get the coastline shapefile (derived from OSM)
eur_shp <- readOGR(system.file("extdata", "eur_coast", package = "europop"), layer = "coastlines_z4") %>% spTransform(CRS("+proj=longlat +datum=WGS84"))
eur_df <- fortify(eur_shp)

# Join city coordinates to the population metrics
pop_points <- europop %>% inner_join(city_coords, by = "city")

saveGIF({
  for(i in seq(1500, 1800, 50)) {

    # Get the points for this year
    subpop <- pop_points %>% filter(year == i)

    p <- ggplot() +
      geom_map(data = eur_df, map = eur_df, aes(x = long, y = lat, group = group, map_id = id), fill = "gray", color = "gray") +
      geom_point(data = subpop, aes(x = lon, y = lat, color = population, size = population)) +
      coord_map() +
      facet_wrap(~ year) +
      theme_minimal() +
      theme(legend.position = "none") +
      ylim(min(pop_points$lat), max(pop_points$lat)) +
      xlim(min(pop_points$lon), max(pop_points$lon))

    plot(p)
  }
}, movie.name = "europop.gif", interval = 0.5)