# Introduction to rnaturalearth.

This vignette is an introduction to rnaturalearth, an R package to hold and facilitate interaction with natural earth vector map data. `rnaturalearth` is a data package designed to provide map data that can be visualised using other R packages.

Natural Earth is a public domain map dataset including vector country and other administrative boundaries.

rnaturalearth does two main things.

1. Contains pre-downloaded vector maps for :
   - countries `ne_countries()`
   - states `ne_states()`
   - coastline `ne_coastline()`
2. Has `ne_download()` function to facilitate download of other vector and raster maps.

This vignette uses `plot` as a simple, quick way to show how different data can be accessed.`rnaturalearth` is designed to provide data allowing creation of more elaborate maps in other visualisation packages (e.g. `ggplot2`, `tmap` and `choroplethr`).

## load required packages

    library(rnaturalearth)

## Maps in the package.

Pre-downloaded maps can be accessed with :

- `ne_countries()` for country (admin-0) boundaries
- `ne_states()` for boundaries within countries (admin-1)
- `ne_coastline()` for world coastline

    # world at small scale (low resolution)
    plot(ne_countries(type = "countries", scale = "small"))
    #> Warning: plotting the first 10 out of 168 attributes; use
    #> max.plot = 168 to plot all

    # countries, UK undivided
    plot(ne_countries(country = "united kingdom", type = "countries"))
    #> Warning: plotting the first 9 out of 168 attributes; use
    #> max.plot = 168 to plot all

    # map_units, UK divided into England, Scotland, Wales and Northern Ireland
    plot(ne_countries(country = "united kingdom", type = "map_units"))
    #> Warning: plotting the first 9 out of 168 attributes; use
    #> max.plot = 168 to plot all

    # countries, small scale
    plot(ne_countries(country = "united kingdom", scale = "small"))
    #> Warning: plotting the first 9 out of 168 attributes; use
    #> max.plot = 168 to plot all

    # countries, medium scale
    plot(ne_countries(country = "united kingdom", scale = "medium"))
    #> Warning: plotting the first 10 out of 168 attributes; use
    #> max.plot = 168 to plot all

    # not evaluated because rely on rnaturalearthhires data which are on rOpenSci so CRAN check likely to fail

    # countries, large scale
    plot(ne_countries(country = "united kingdom", scale = "large"))

    # states country='united kingdom'
    plot(ne_states(country = "united kingdom"))
    # states geounit='england'
    plot(ne_states(geounit = "england"))

    # states country='france'
    plot(ne_states(country = "france"))

    # coastline of the world
    # subsetting of coastline is not possible because the Natural Earth data are not attributed in that way
    plot(ne_coastline())

## Downloading other Natural Earth vectors with ne_download().

Each Natural Earth dataset is characterised on the website according to `scale`, `type` and `category`. rnaturalearth allows you to specify `scale`, `type` and `category` and will construct the url and download the corresponding file.

    # lakes
    lakes110 <- ne_download(scale = 110, type = "lakes", category = "physical")
    plot(lakes110, col = "blue")

    # rivers
    rivers110 <- ne_download(scale = 110, type = "rivers_lake_centerlines", category = "physical")
    plot(rivers110, col = "blue")

## Tables of vector layers available via `ne_download(type=[layer_name], scale=)`

1=available, 0=not

category=‘physical’ vector data available via ne_download()
layer | scale10 | scale50 | scale110
--- | --- | --- | ---
antarctic_ice_shelves_lines | 1 | 1 | 0
antarctic_ice_shelves_polys | 1 | 1 | 0
coastline | 1 | 1 | 1
geographic_lines | 1 | 1 | 1
geography_marine_polys | 1 | 1 | 1
geography_regions_elevation_points | 1 | 1 | 1
geography_regions_points | 1 | 1 | 1
geography_regions_polys | 1 | 1 | 1
glaciated_areas | 1 | 1 | 1
lakes | 1 | 1 | 1
lakes_europe | 1 | 0 | 0
lakes_historic | 1 | 1 | 0
lakes_north_america | 1 | 0 | 0
lakes_pluvial | 1 | 0 | 0
land | 1 | 1 | 1
land_ocean_label_points | 1 | 0 | 0
land_ocean_seams | 1 | 0 | 0
land_scale_rank | 1 | 0 | 0
minor_islands | 1 | 0 | 0
minor_islands_coastline | 1 | 0 | 0
minor_islands_label_points | 1 | 0 | 0
ocean | 1 | 1 | 1
ocean_scale_rank | 1 | 0 | 0
playas | 1 | 1 | 0
reefs | 1 | 0 | 0
rivers_europe | 1 | 0 | 0
rivers_lake_centerlines | 1 | 1 | 1
rivers_lake_centerlines_scale_rank | 1 | 1 | 0
rivers_north_america | 1 | 0 | 0

category=‘cultural’ vector data available via ne_download()
layer | scale10 | scale50 | scale110
--- | --- | --- | ---
admin_0_antarctic_claim_limit_lines | 1 | 0 | 0
admin_0_antarctic_claims | 1 | 0 | 0
admin_0_boundary_lines_disputed_areas | 1 | 1 | 0
admin_0_boundary_lines_land | 1 | 1 | 1
admin_0_boundary_lines_map_units | 1 | 0 | 0
admin_0_boundary_lines_maritime_indicator | 1 | 1 | 0
admin_0_boundary_map_units | 0 | 1 | 0
admin_0_breakaway_disputed_areas | 0 | 1 | 0
admin_0_countries | 1 | 1 | 1
admin_0_countries_lakes | 1 | 1 | 1
admin_0_disputed_areas | 1 | 0 | 0
admin_0_disputed_areas_scale_rank_minor_islands | 1 | 0 | 0
admin_0_label_points | 1 | 0 | 0
admin_0_map_subunits | 1 | 1 | 0
admin_0_map_units | 1 | 1 | 1
admin_0_pacific_groupings | 1 | 1 | 1
admin_0_scale_rank | 1 | 1 | 1
admin_0_scale_rank_minor_islands | 1 | 0 | 0
admin_0_seams | 1 | 0 | 0
admin_0_sovereignty | 1 | 1 | 1
admin_0_tiny_countries | 0 | 1 | 1
admin_0_tiny_countries_scale_rank | 0 | 1 | 0
admin_1_label_points | 1 | 0 | 0
admin_1_seams | 1 | 0 | 0
admin_1_states_provinces | 1 | 1 | 1
admin_1_states_provinces_lakes | 1 | 1 | 1
admin_1_states_provinces_lines | 1 | 1 | 1
admin_1_states_provinces_scale_rank | 1 | 1 | 1
airports | 1 | 1 | 0
parks_and_protected_lands_area | 1 | 0 | 0
parks_and_protected_lands_line | 1 | 0 | 0
parks_and_protected_lands_point | 1 | 0 | 0
parks_and_protected_lands_scale_rank | 1 | 0 | 0
populated_places | 1 | 1 | 1
populated_places_simple | 1 | 1 | 1
ports | 1 | 1 | 0
railroads | 1 | 0 | 0
railroads_north_america | 1 | 0 | 0
roads | 1 | 0 | 0
roads_north_america | 1 | 0 | 0
time_zones | 1 | 0 | 0
urban_areas | 1 | 1 | 0
urban_areas_landscan | 1 | 0 | 0