Определение расстояния на карте

[†‡Paladin‡†]

Класс не очень точен, но для больших карт (и даже для масштаба города) вполне подходит.

package fzn7.utils
{
	public class GeoUtil extends Object
	{

	/**
	 * Helper function 
	 * */
        static private function deg2rad(degrees:Number):Number {
            var retVal:Number = degrees * Math.PI / 180;
            return retVal;
        }

	/**
	 * Helper function 
	 * */
        static private function rad2deg(radians:Number):Number {
            var retVal:Number = radians * 180 / Math.PI;
            return retVal;
        }

	/**
	 * Function finds distance between 2 geo points.
	 * */
        static public function getDistance(lat1:Number, lon1:Number, lat2:Number, lon2:Number, units:String = "K"): Number {
            var distance:Number = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + 
            					    Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * 
            					        Math.cos(deg2rad(lon1 - lon2));
            					        
            distance = Math.acos(distance);
            distance = rad2deg(distance);
            
            var retVal:Number = distance * 60 * 1.1515;
            
            units = units.toUpperCase();
            if (units == "K")
            {
                return retVal * 1.60934;
            }
            if (units == "N")
            {
                return retVal * 0.8684;
            }
            return undefined;
        }
    }
}