标签:color long math nal code 返回 logs 精度 abs
private static final double EARTH_RADIUS = 6378137;//赤道半径(单位m) /** * 转化为弧度(rad) * */ private static double rad(double d) { return d * Math.PI / 180.0; } /** * 基于余弦定理求两经纬度距离 * @param lon1 第一点的精度 * @param lat1 第一点的纬度 * @param lon2 第二点的精度 * @param lat3 第二点的纬度 * @return 返回的距离,单位km * */ public static double LantitudeLongitudeDist(double lon1, double lat1,double lon2, double lat2) { double radLat1 = rad(lat1); double radLat2 = rad(lat2); double radLon1 = rad(lon1); double radLon2 = rad(lon2); if (radLat1 < 0) radLat1 = Math.PI / 2 + Math.abs(radLat1);// south if (radLat1 > 0) radLat1 = Math.PI / 2 - Math.abs(radLat1);// north if (radLon1 < 0) radLon1 = Math.PI * 2 - Math.abs(radLon1);// west if (radLat2 < 0) radLat2 = Math.PI / 2 + Math.abs(radLat2);// south if (radLat2 > 0) radLat2 = Math.PI / 2 - Math.abs(radLat2);// north if (radLon2 < 0) radLon2 = Math.PI * 2 - Math.abs(radLon2);// west double x1 = EARTH_RADIUS * Math.cos(radLon1) * Math.sin(radLat1); double y1 = EARTH_RADIUS * Math.sin(radLon1) * Math.sin(radLat1); double z1 = EARTH_RADIUS * Math.cos(radLat1); double x2 = EARTH_RADIUS * Math.cos(radLon2) * Math.sin(radLat2); double y2 = EARTH_RADIUS * Math.sin(radLon2) * Math.sin(radLat2); double z2 = EARTH_RADIUS * Math.cos(radLat2); double d = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)+ (z1 - z2) * (z1 - z2)); //余弦定理求夹角 double theta = Math.acos((EARTH_RADIUS * EARTH_RADIUS + EARTH_RADIUS * EARTH_RADIUS - d * d) / (2 * EARTH_RADIUS * EARTH_RADIUS)); double dist = theta * EARTH_RADIUS; return dist; }
标签:color long math nal code 返回 logs 精度 abs
原文地址:http://www.cnblogs.com/IWings/p/6372871.html