find_stations returns a tibble with the nearest stations' distances using a given point's longitude and latitude values. This function uses the Haversine formula for distance calculation in km.

find_stations(longitude = 24, latitude = 38)

Arguments

longitude

a numeric value in degrees

latitude

a numeric value in degrees

Value

If the given longitude is in [24, 38] and the latitude is in [34, 42] (i.e. are valid values for Greece) returns an ordered tibble with the station_id, name, subdomain and distance values in km. The station's data that are used come from the `stations` dataset. Otherwise returns an error message.

Examples


# find the five nearest stations to a point near Thessaloniki,
# (lon, lat) = (22.97, 40.60)
head(find_stations(22.97, 40.60), 5)
#> # A tibble: 5 × 4
#>   station_id name                   subdomain distance
#>        <int> <chr>                  <chr>        <dbl>
#> 1      20158 MS Thessalonikes       emy           2.96
#> 2      20201 A.M. SCHOLE THES/NIKES emy           3.97
#> 3      10032 THESSALONIKE           kyy           4.56
#> 4      20032 SEDES                  emy           6.88
#> 5      20033 MIKRA (THES/KES)       emy           8.07