[펌]안드로이드 구글맵 거리계산, 좌표계산

출처 : http://stbaeya.com/tc/225?category=45
안드로이드 구글맵 거리계산, 좌표계산

Location API를 통한 좌표로 거리 계산하기.

double distance;
 
Location locationA = new Location("point A");
 
locationA.setLatitude(latA);
locationA.setLongitude(lngA);
 
Location locationB = new Location("point B");
 
locationB.setLatitude(latB);
LocationB.setLongitude(lngB);
 
distance = locationA.distanceTo(locationB);
 

그리고 distanceBetween() 사용하기.

float[] results = new float[3];
Location location = new Location("start");
location.distanceBetween(
startLatitude, 
startLongitude, 
endLatitude,
endLongitude,
results);
Sring mes = Float.toString(results[0]);
 
========================================================================================
The computed distance is stored in results[0]. 

If results has length 2 or greater, the initial bearing is stored in results[1].

If results has length 3 or greater, the final bearing is stored in results[2].
 

또 하나는 국토지리원에서 공개한 거리계산 함수 사용하기.

public double distance(double P1_latitude, double P1_longitude,
			double P2_latitude, double P2_longitude) {
		if ((P1_latitude == P2_latitude) && (P1_longitude == P2_longitude)) {
			return 0;
		}
 
		double e10 = P1_latitude * Math.PI / 180;
		double e11 = P1_longitude * Math.PI / 180;
		double e12 = P2_latitude * Math.PI / 180;
		double e13 = P2_longitude * Math.PI / 180;
 
		/* 타원체 GRS80 */
		double c16 = 6356752.314140910;
		double c15 = 6378137.000000000;
		double c17 = 0.0033528107;
 
		double f15 = c17 + c17 * c17;
		double f16 = f15 / 2;
		double f17 = c17 * c17 / 2;
		double f18 = c17 * c17 / 8;
		double f19 = c17 * c17 / 16;
 
		double c18 = e13 - e11;
		double c20 = (1 - c17) * Math.tan(e10);
		double c21 = Math.atan(c20);
		double c22 = Math.sin(c21);
		double c23 = Math.cos(c21);
		double c24 = (1 - c17) * Math.tan(e12);
		double c25 = Math.atan(c24);
		double c26 = Math.sin(c25);
		double c27 = Math.cos(c25);
 
		double c29 = c18;
		double c31 = (c27 * Math.sin(c29) * c27 * Math.sin(c29))
				+ (c23 * c26 - c22 * c27 * Math.cos(c29))
				* (c23 * c26 - c22 * c27 * Math.cos(c29));
		double c33 = (c22 * c26) + (c23 * c27 * Math.cos(c29));
		double c35 = Math.sqrt(c31) / c33;
		double c36 = Math.atan(c35);
		double c38 = 0;
		if (c31 == 0) {
			c38 = 0;
		} else {
			c38 = c23 * c27 * Math.sin(c29) / Math.sqrt(c31);
		}
 
		double c40 = 0;
		if ((Math.cos(Math.asin(c38)) * Math.cos(Math.asin(c38))) == 0) {
			c40 = 0;
		} else {
			c40 = c33 - 2 * c22 * c26
					/ (Math.cos(Math.asin(c38)) * Math.cos(Math.asin(c38)));
		}
 
		double c41 = Math.cos(Math.asin(c38)) * Math.cos(Math.asin(c38))
				* (c15 * c15 - c16 * c16) / (c16 * c16);
		double c43 = 1 + c41 / 16384
				* (4096 + c41 * (-768 + c41 * (320 - 175 * c41)));
		double c45 = c41 / 1024 * (256 + c41 * (-128 + c41 * (74 - 47 * c41)));
		double c47 = c45
				* Math.sqrt(c31)
				* (c40 + c45
						/ 4
						* (c33 * (-1 + 2 * c40 * c40) - c45 / 6 * c40
								* (-3 + 4 * c31) * (-3 + 4 * c40 * c40)));
		double c50 = c17
				/ 16
				* Math.cos(Math.asin(c38))
				* Math.cos(Math.asin(c38))
				* (4 + c17
						* (4 - 3 * Math.cos(Math.asin(c38))
								* Math.cos(Math.asin(c38))));
		double c52 = c18
				+ (1 - c50)
				* c17
				* c38
				* (Math.acos(c33) + c50 * Math.sin(Math.acos(c33))
						* (c40 + c50 * c33 * (-1 + 2 * c40 * c40)));
 
		double c54 = c16 * c43 * (Math.atan(c35) - c47);
 
		// return distance in meter
		return c54;
	}
 
	public short bearingP1toP2(double P1_latitude, double P1_longitude, double P2_latitude, double P2_longitude)
    {
        // 현재 위치 : 위도나 경도는 지구 중심을 기반으로 하는 각도이기 때문에 라디안 각도로 변환한다.
        double Cur_Lat_radian = P1_latitude * (3.141592 / 180);
        double Cur_Lon_radian = P1_longitude * (3.141592 / 180);
 
 
        // 목표 위치 : 위도나 경도는 지구 중심을 기반으로 하는 각도이기 때문에 라디안 각도로 변환한다.
        double Dest_Lat_radian = P2_latitude * (3.141592 / 180);
        double Dest_Lon_radian = P2_longitude * (3.141592 / 180);
 
        // radian distance
        double radian_distance = 0;
        radian_distance = Math.acos(Math.sin(Cur_Lat_radian) * Math.sin(Dest_Lat_radian) 
        		+ Math.cos(Cur_Lat_radian) * Math.cos(Dest_Lat_radian) * Math.cos(Cur_Lon_radian - Dest_Lon_radian));
 
        // 목적지 이동 방향을 구한다.(현재 좌표에서 다음 좌표로 이동하기 위해서는 방향을 설정해야 한다. 라디안값이다.
        double radian_bearing = Math.acos((Math.sin(Dest_Lat_radian) - Math.sin(Cur_Lat_radian)
        		* Math.cos(radian_distance)) / (Math.cos(Cur_Lat_radian) * Math.sin(radian_distance)));	
 
        // acos의 인수로 주어지는 x는 360분법의 각도가 아닌 radian(호도)값이다.		
 
        double true_bearing = 0;
        if (Math.sin(Dest_Lon_radian - Cur_Lon_radian) < 0)
        {
            true_bearing = radian_bearing * (180 / 3.141592);
            true_bearing = 360 - true_bearing;
        }
        else
        {
            true_bearing = radian_bearing * (180 / 3.141592);
        }
 
        return (short)true_bearing;
    }

둘다 코드로 돌려보았지만, 결과값은 비슷한듯...