map.where {maps} | R Documentation |
Locate points on a map
Description
Returns the region names containing given locations.
Usage
map.where(database = "world", x, y, ...)
Arguments
database |
character string naming a geographical database, or a list of
|
x |
vector of longitudes. |
y |
vector of latitudes. |
... |
Options for |
.
Value
A list of character strings, naming the map region that each (longitude, latitude) pair falls into.
Note
For points close to a border (polygon boundary), the result may be wrong if the resolution of the database is insufficient. This function may also give erroneous results if the database contains enclaves. For instance, a point in San Marino may also be identified as being in Italy.
Author(s)
Tom Minka
See Also
in.polygon
Examples
# NYC
map.where("state", -73.8, 41)
# Auckland
map.where("nz", 174.6, -36.92)
# find both in the world
map.where(x = c(174.6, -73.8), y = c(-36.92, 41))
# with a map object:
m = map("state", "new york", fill = TRUE, plot = FALSE)
map.where(m, -73.8, 41)
[Package maps version 3.4.2 Index]