map.cities {maps}R Documentation

Add Cities to Existing Map

Description

Adds city locations and (optionally) names to an existing map using a specified database.

Usage

map.cities(x = world.cities, country = "", label = NULL, minpop = 0,
maxpop = Inf, capitals = 0, cex = par("cex"), ...)

Arguments

x Name of database. See world.cities to determine the structure of the database.
country If the string country is specified, limit the displayed cities to be from within the specified country.
label If TRUE, label all cities. If NULL, the cities will be labelled unless there are 20 or more.
minpop The minimum value of population below which a particular city will not be shown.
maxpop The maximum value of population above which a particular city will not be shown.
capitals Selection of capitals-only display. Capitals may be 1 (country capital), 2 (provincial, state, or regional capital) or 3 (local capital). See world.cities for further information.
cex The value of cex acts to override the current value of character size expansion.
... Further plotting parameters may be specified as for the commands points and text.

Details

The database is searched for all cities matching the specified criteria and fitting within the limits of the plot currently displayed. The default database is of all cities that have a population greater than 100,000 or which are capital cities of a country or island territory. The data are from around 1980-1990.

Value

No value is returned from map.cities.

NOTE

This function is available only if no projection= has been specified in the map() call.

Side Effects

All cities within the boundaries of the plot containing the current map are added to the plot. Note that it is possible that the boundaries of the plot exceed the boundaries of the map requested, and so more cities than were expected might be shown.

See Also

world.cities

Examples

map("world", "China")
map.cities(country = "China", capitals = 2)

[Package maps version 2.0-25 Index]