check_data_exist function

check whether the requested data exist on Natural Earth

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.

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

Arguments

• scale: The scale of map to return, one of 110, 50, 10 or small, medium, large.
• 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'
• category: one of natural earth categories : 'cultural', 'physical', 'raster'

Returns

TRUE or FALSE

Details

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

Examples

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

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

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

See Also

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