# Find nearest geographic coordinates

Ivan Uemlianin ivan@REDACTED
Wed Nov 25 23:13:54 CET 2020

```Ooh interesting.  Well there's your answer, although if you're always
using it for `distance(A, X) < distance(B, X)` you could probably
simplify the arithmetic.

Ivan

On 25/11/2020 22:09, Frank Muller wrote:
> I’m new to GIS field, but this module states that Euclidian distance
> isn’t accurate compared to “Law of Haversines”:
>
> https://github.com/armon/teles/blob/master/src/teles_geo_query.erl#L87-L102
>
>
> /Frank
>
> Wed 25 nov. 2020 à 22:45, Ivan Uemlianin <ivan@REDACTED
> <mailto:ivan@REDACTED>> wrote:
>
>     Hi Frank
>
>     Do you want to sort the list by Euclidean distance from X? If so,
>     could
>     you use lists:sort/2?
>
>     Ivan
>
>
>     On 25/11/2020 21:38, Frank Muller wrote:
>     > Hi guys,
>     >
>     > I've a list of geographic coordinates:
>     >
>     > L = [ {{<<"longitude">>,6.1457}, {<<"latitude">>,46.2022}},
>     >       {{<<"longitude">>,2.3387}, {<<"latitude">>,48.8582}},
>     >       ... ]
>     >
>     > and a specific coordinate X = {{<<"longitude">>,-73.5848},
>     > {<<"latitude">>,45.4995}}.
>     >
>     > Question: how can i find the nearest coordinates to X from L
>     (sorted
>     > from the nearest to the farest)?
>     >
>     > /Frank
>
>     --
>     ============================================================
>     Ivan A. Uemlianin PhD
>     Llaisdy
>
>     Ymchwil a Datblygu Technoleg Lleferydd
>     Speech Technology Research and Development
>
>     ivan@REDACTED <mailto:ivan@REDACTED>
>                              @llaisdy
>     llaisdy.wordpress.com <http://llaisdy.wordpress.com>
>     github.com/llaisdy <http://github.com/llaisdy>
>
>                              festina lente
>     ============================================================
>

--
============================================================
Ivan A. Uemlianin PhD
Llaisdy

Ymchwil a Datblygu Technoleg Lleferydd
Speech Technology Research and Development

ivan@REDACTED
@llaisdy
llaisdy.wordpress.com
github.com/llaisdy