cley - 8 months ago 75

Javascript Question

How do i identify if a point with a **LAT, LONG coordinate format** is near to other point.

*Lets Say i want to find all the points near to*:

`-38.9086621 ,-68.082214`

That are at less than 1km of distance. I already know how to find a coordinate in a given quadrant but not how to find a quadrant near a point.

Answer

You can use the haversine formular to calculate distances between two given coordinates. The calculated distance is the direct connection between the given coordinates (beeline).

JavaScript example (Source):

```
var R = 6371e3; // meters
var lat1Radians = lat1.toRadians();
var lat2Radians = lat2.toRadians();
var deltaLat = (lat2-lat1).toRadians();
var deltaLon = (lon2-lon1).toRadians();
var a = Math.sin(deltaLat/2) * Math.sin(deltaLat/2) +
Math.cos(lat1Radians) * Math.cos(lat2Radians) *
Math.sin(deltaLon/2) * Math.sin(deltaLon/2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var d = R * c;
```