=== versions ===
python 3.12.0 | cartopy 0.26.0 | matplotlib 3.11.2 | geopandas 1.2.0 | mapclassify 2.11.0 | matplotlib-scalebar 0.9.0 | rasterio 1.5.2

=== Step 1: Natural Earth and four projections ===
Natural Earth 110m land: 127 polygons, CRS EPSG:4326
area of a 1 x 1 degree cell in the projection / true area:
 lat  true_km2  PlateCarree  Mercator  Equal Earth
 0.0 12308.310        1.005     1.000          1.0
30.0 10642.104        1.162     1.345          1.0
53.5  7298.450        1.694     2.882          1.0
70.0  4157.854        2.974     8.924          1.0

=== Step 2: world choropleth of population density (Natural Earth 50m, Equal Earth) ===
240 countries with a population estimate; POP_YEAR values: [np.int32(2018), np.int32(2019), np.int32(2020)]
quantile breaks (people per km2): [18.9, 51.0, 88.4, 151.9, 349.7, 28236.2]
     NAME  density
    Macao  28236.0
Singapore  11814.0
 Maldives   8030.0
United Kingdom: 277.7 per km2

=== Step 3: England and Wales local authorities and Census 2021 density ===
331 local authority districts; 0 without a census value
density: median 615, min 25.5 (Eden), max 15,703 (Tower Hamlets) usual residents per km2
class breaks and counts:
  Equal interval                      breaks [2638, 5251, 7864, 10477, 13090, 15703]  counts [260, 51, 7, 6, 4, 3]  GADF 0.633
  Quantiles                           breaks [158, 338, 615, 1513, 3315, 15703]  counts [56, 55, 55, 55, 55, 55]  GADF 0.663
  Fisher-Jenks (natural breaks)       breaks [789, 2005, 3798, 7173, 11839, 15703]  counts [178, 62, 48, 29, 11, 3]  GADF 0.796
  Manual (rounded, roughly doubling)  breaks [100, 250, 500, 1000, 2500, 5000, 15703]  counts [25, 67, 48, 52, 62, 52, 25]  GADF 0.720

=== Step 4: a publication-quality map of England and Wales ===
grid convergence at the north arrow: true north is +3.27 degrees from grid north
  04-england-wales-density-map.png: 554 KB, 1417 x 1653 px
  04-england-wales-density-map.pdf: 2,997 KB
  04-england-wales-density-map.svg: 8,791 KB
  100 km of grid at easting 100,000 m = 99.97 km on the ground
  100 km of grid at easting 400,000 m = 100.05 km on the ground
  100 km of grid at easting 650,000 m = 99.94 km on the ground

=== Step 5: shaded relief of Greater Manchester (Copernicus DEM GLO-30) ===
Greater Manchester districts: 10
DEM tiles: ['Copernicus_DSM_COG_10_N53_00_W002_00_DEM', 'Copernicus_DSM_COG_10_N53_00_W003_00_DEM']
DEM 2214 x 1729 px at 30 m; elevation -2 to 634 m
inside Greater Manchester: 7 to 539 m, mean 123 m
saved figures: ['01-map-projections-tissot.png', '02-world-population-density.png', '03-classification-schemes.png', '04-england-wales-density-map.png', '05-greater-manchester-terrain.png', '06-england-wales-density-map-dark.png']