elixir_way.ex

# Old
[latStr, lngStr] = String.split(geo, ",")
{lat, _} = Float.parse(latStr)
{lng, _} = Float.parse(lngStr)

[bl, tr] = Geocalc.bounding_box([lat,lng], 10_000)
[lat1, lng1] = bl;
[lat2, lng2] = tr;
coords = "#{lat1}, #{lng1}, #{lat2}, #{lng2}"

# new
# coords = bounding_box(geo, 50_000)
defp bounding_box(geo, distance \\ 50_000) do
  String.split(geo, ",") 
    |> Enum.map(fn(v) -> String.to_float(v) end) 
    |> Geocalc.bounding_box(distance) 
    |> Enum.map(fn([lat,lng]) -> "#{lat},#{lng}" end) 
    |> Enum.join(",")
end