GeoLocation.cs

usingSystem;

namespaceAlgorithms.Other;

publicstaticclassGeoLocation
{
privateconstdoubleEarthRadiusKm=6371.01d;

/// <summary>
/// Calculates spherical distance between 2 points given their latitude, longitude coordinates.
/// https://www.movable-type.co.uk/scripts/latlong.html.
/// </summary>
/// <param name="lat1">Latitude of point A.</param>
/// <param name="lng1">Longitude of point A.</param>
/// <param name="lat2">Latitude of point B.</param>
/// <param name="lng2">Longitude of point B.</param>
/// <returns>Spherical distance between A and B.</returns>
publicstaticdoubleCalculateDistanceFromLatLng(doublelat1,doublelng1,doublelat2,doublelng2)
{
varpi180=Math.PI/180d;
varlat1Radian=lat1*pi180;
varlng1Radian=lng1*pi180;
varlat2Radian=lat2*pi180;
varlng2Radian=lng2*pi180;

vardiffLat=lat2Radian-lat1Radian;
vardiffLng=lng2Radian-lng1Radian;

varhaversine=
Math.Sin(diffLat/2)*Math.Sin(diffLat/2)
+Math.Cos(lat1Radian)*Math.Cos(lat2Radian)*Math.Sin(diffLng/2)*Math.Sin(diffLng/2);
vardistance=EarthRadiusKm*(2d*Math.Atan2(Math.Sqrt(haversine),Math.Sqrt(1-haversine)));

returndistance*1000;// Convert from km -> m
}
}