check_data_exist: check whether the requested data exist on Natural Earth

In AndySouth/rnaturalearth: World Map Data from Natural Earth

check whether the requested data exist on Natural Earth

Description

checks from a list dependent on type, category and scale. If it returns FALSE the data may still exist on the website. Doesn't yet do checking on raster names because I found the naming convention too tricky.

Usage

check_data_exist(
  type,
  scale = 110L,
  category = c("cultural", "physical", "raster")
)

Arguments

type	type of natural earth file to download one of 'countries', 'map_units', 'map_subunits', 'sovereignty', 'states' OR the portion of any natural earth vector url after the scale and before the . e.g. for 'ne_50m_urban_areas.zip' this would be 'urban_areas' OR the raster filename e.g. for 'MSR_50M.zip' this would be 'MSR_50M'
scale	The scale of map to return, one of '110', '50', '10' or 'small', 'medium', 'large'.
category	one of natural earth categories : 'cultural', 'physical', 'raster'

Details

Note that the filename of the requested object will be returned if 'load = FALSE'.

If the data is to be loaded into memory ('load = TRUE'), the download will be handled using the GDAL virtual file system, allowing direct access to the data without writing it to disk.

Value

TRUE or FALSE

See Also

ne_load, pre-downloaded data are available using ne_countries, ne_states. Other geographic data are available in the raster package : getData.

Examples

check_data_exist(type = "countries", scale = 110, category = "cultural")

# Type not in list for this category
check_data_exist(type = "airports", scale = 110, category = "physical")

# Type in list but scale shows FALSE
check_data_exist(type = "airports", scale = 110, category = "cultural")

AndySouth/rnaturalearth documentation built on April 14, 2025, 3:22 a.m.