Day 14 of the #30DayMapChallenge - Boundaries

I tested cartography.

Load packages:

  library(sf)
  library(cartography)

# path to the geopackage file embedded in cartography
  path_to_gpkg <- system.file("gpkg/mtq.gpkg", package="cartography")

# import to an sf object
  mtq <- st_read(dsn = path_to_gpkg, quiet = TRUE)

# Compute the population density (inhab./km2) using sf::st_area()
  mtq$POPDENS <- as.numeric(1e6 * mtq$POP / st_area(mtq))

# Get a SpatialLinesDataFrame of countries borders
  mtq.contig <- getBorders(mtq)
  
# get the figure ratio
  sizes <- getFigDim(x = mtq, width = 1200, mar = c(0, 0, 1.2, 0))
  
# plot municipalities (only the backgroung color is plotted)
  plot(st_geometry(mtq), col = NA, border = NA, bg = "lightblue1", 
       xlim = c(690574, 745940))

# Plot the population density with custom breaks
  choroLayer(x = mtq,
             var = "MED",
             breaks = c(min(mtq$MED), seq(13000, 21000, 2000), max(mtq$MED)),
             col = carto.pal("green.pal", 6),
             border = "white",
             lwd = 0.5, 
             legend.pos = "topright",
             legend.title.txt = "Median Income\n(euros)",
             add = TRUE)
# Plot discontinuities
  discLayer(
    x = mtq.contig, 
    df = mtq, 
    var = "MED",
    type = "rel", 
    method = "geom", 
    nclass = 3,
    threshold = 0.4,
    sizemin = 0.7, 
    sizemax = 6, 
    col = "red4",
    legend.values.rnd = 1, 
    legend.title.txt = "Relative\nDiscontinuities", 
    legend.pos = "right",
    add = TRUE
  )
# Layout
  layoutLayer(title = "Wealth Disparities in Martinique, 2015", 
              author =  paste0("cartography ", packageVersion("cartography")),
              sources = "Sources: Insee and IGN, 2018",
              frame = FALSE, scale = 5, tabtitle = TRUE,theme = "grey.pal")
# north arrow
  north(pos = "topleft")