add_coordinates {epiflows}

Add/Retrieve location coordinates

Description

Adds/Retrieves longitude/latitude values to location data within an epiflows object. Coordinates are added to object's locations slot as lon and lat columns.

Usage

add_coordinates(
  x,
  coordinates = c("lon", "lat"),
  loc_column = "id",
  overwrite = FALSE
)

get_coordinates(x, ...)

## S3 method for class 'epiflows'
get_coordinates(x, location = NULL, ...)

Arguments

x

An epiflows object.

coordinates

Either names of the appended columns with longitudes and latitudes, respectively (default: "lon" and "lat") or a data frame with longitude and latitude columns.

loc_column

Name of the column where location names are stored (default: "country").

overwrite

If TRUE, retrieves all geocodes, even those already retrieved. If FALSE (default), overwrites only NAs.

...

unused

location

a character specifying a single location to return as a vector of coordinates. You cannot specify multiple locations with this parameter. Defaults to 'NULL', indicating all locations.

Value

An updated epiflows object.

Author(s)

Pawel Piatkowski, Salla Toikkanen, Zhian Kamvar

See Also

map_epiflows(); plot.epiflows(); get_locations(); get_vars(); global_vars()

Examples

# Setting up the data
data("Brazil_epiflows")
data("YF_coordinates")
get_coordinates(Brazil_epiflows) # no coordinates yet
ef <- add_coordinates(Brazil_epiflows, YF_coordinates[-1])
get_coordinates(ef)
get_coordinates(ef, location = "Espirito Santo") # coordinates for Espirito Santo
if (interactive()) {
  # You can use google maps' geocode functionality if you have a decent 
  # internet connection
  # NOTE: you may need to authenticate with Google Maps API beforehand
  # using ggmap::register_google()
  ef2 <- add_coordinates(Brazil_epiflows, loc_column = "id")
  ef2
}