table_getLocationID {MazamaLocationUtils} | R Documentation |
Return IDs of known locations
Description
Returns a vector of locationID
s for the known locations
that each incoming location will be assigned to within the given. If more
than one known location exists within the given distanceThreshold
, the closest will be
assigned. NA
will be returned for each incoming that cannot be
assigned to a known location in locationTbl
.
Usage
table_getLocationID(
locationTbl = NULL,
longitude = NULL,
latitude = NULL,
distanceThreshold = NULL,
measure = c("geodesic", "haversine", "vincenty", "cheap")
)
Arguments
locationTbl |
Tibble of known locations. |
longitude |
Vector of longitudes in decimal degrees E. |
latitude |
Vector of latitudes in decimal degrees N. |
distanceThreshold |
Distance in meters. |
measure |
One of "geodesic", "haversine", "vincenty" or "cheap"
specifying desired method of geodesic distance calculation.
See |
Value
Vector of known locationID
s.
Note
The measure "cheap"
may be used to speed things up depending on
the spatial scale being considered. Distances calculated with
measure = "cheap"
will vary by a few meters compared with those
calculated using measure = "geodesic"
.
Examples
locationTbl <- get(data("wa_monitors_500"))
# Wenatchee
lon <- -120.325278
lat <- 47.423333
# Too small a distanceThreshold will not find a match
table_getLocationID(locationTbl, lon, lat, distanceThreshold = 50)
# Expanding the distanceThreshold will find one
table_getLocationID(locationTbl, lon, lat, distanceThreshold = 5000)