/[projects]/dao/FuldDaekningWorker/src/dk/daoas/fulddaekning/GeoPoint.java
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Contents of /dao/FuldDaekningWorker/src/dk/daoas/fulddaekning/GeoPoint.java

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Revision 2579 - (show annotations) (download)
Thu Jun 11 21:10:17 2015 UTC (8 years, 11 months ago) by torben
File size: 8095 byte(s)
use haversine method for calculating distances
1 package dk.daoas.fulddaekning;
2
3 public class GeoPoint {
4
5 public double latitude;
6 public double longitude;
7
8 public GeoPoint() { //Default
9 }
10
11 public GeoPoint(double lat, double lng) { //Default
12 latitude=lat;
13 longitude=lng;
14 }
15
16 //Denne er alt for upræcis
17 @Deprecated
18 public static double beregnAfstand_old(GeoPoint point1, GeoPoint point2) {
19 //(62.8*sqrt(3.1*(Power(a.Latitude-x.Latitude,2)+Power(a.Longitude-x.Longitude,2)))) as Afstand,
20
21
22 double pwrLat = Math.pow(point1.latitude - point2.latitude, 2);
23 double pwrLng = Math.pow(point1.longitude - point2.longitude, 2);
24
25 return 62.8 * Math.sqrt( 3.1 * (pwrLat + pwrLng) );
26 }
27
28 /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
29 /*:: This function converts decimal degrees to radians :*/
30 /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
31 private static double deg2rad(double deg) {
32 return (deg * Math.PI / 180.0);
33 }
34
35 /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
36 /*:: This function converts radians to decimal degrees :*/
37 /*:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::*/
38 private static double rad2deg(double rad) {
39 return (rad * 180 / Math.PI);
40 }
41
42 //http://www.geodatasource.com/developers/java
43 private static double distanceHaversine(double lat1, double lon1, double lat2, double lon2) {
44 double theta = lon1 - lon2;
45 double dist = Math.sin(deg2rad(lat1)) * Math.sin(deg2rad(lat2)) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.cos(deg2rad(theta));
46 dist = Math.acos(dist);
47 dist = rad2deg(dist);
48 dist = dist * 60 * 1.1515;
49
50 //indtil nu er dist i miles - så vi omregner lige til km
51 dist = dist * 1.609344;
52 return (dist);
53 }
54
55 public static double beregnAfstand(GeoPoint p1, GeoPoint p2) {
56 return distanceHaversine(p1.latitude, p1.longitude, p2.latitude, p2.longitude);
57 }
58
59
60 // denne er nok den mest præcise - men er også den langsomste
61 public static float beregnAfstand_google(GeoPoint p1, GeoPoint p2) {
62 float[] result = new float[1];
63
64 computeDistanceAndBearing(p1.latitude, p1.longitude, p2.latitude, p2.longitude, result);
65
66 return (result[0] / 1000.0f);
67 }
68
69
70 //Latitude (horizonal), longitude(vertical) so
71 // 1 degree latitude is ~ 111320 meters, since the distance between the horizonal lines is always the same
72 // 1 degree longitude is ~111320 meters at equator but gets shorter as we get closer to the poles.
73 // so 1 degree longitude is 64.5 km at denmarks southern point (gedser=54.55,11.95)
74 // and is 59.4km at northern point (skagen = 57.75,10.65)
75
76 public static double kmToLatitude(double km) {
77 return km / 111.320 ;
78 }
79
80 public static double kmToLongitude( double km) {//denne er kun ca
81 return km / 62.0;
82 }
83
84
85
86 //Kopieret fra android.location.Location
87 private static void computeDistanceAndBearing(double lat1, double lon1,
88 double lat2, double lon2, float[] results) {
89 // Based on http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
90 // using the "Inverse Formula" (section 4)
91
92 int MAXITERS = 20;
93 // Convert lat/long to radians
94 lat1 *= Math.PI / 180.0;
95 lat2 *= Math.PI / 180.0;
96 lon1 *= Math.PI / 180.0;
97 lon2 *= Math.PI / 180.0;
98
99 double a = 6378137.0; // WGS84 major axis
100 double b = 6356752.3142; // WGS84 semi-major axis
101 double f = (a - b) / a;
102 double aSqMinusBSqOverBSq = (a * a - b * b) / (b * b);
103
104 double L = lon2 - lon1;
105 double A = 0.0;
106 double U1 = Math.atan((1.0 - f) * Math.tan(lat1));
107 double U2 = Math.atan((1.0 - f) * Math.tan(lat2));
108
109 double cosU1 = Math.cos(U1);
110 double cosU2 = Math.cos(U2);
111 double sinU1 = Math.sin(U1);
112 double sinU2 = Math.sin(U2);
113 double cosU1cosU2 = cosU1 * cosU2;
114 double sinU1sinU2 = sinU1 * sinU2;
115
116 double sigma = 0.0;
117 double deltaSigma = 0.0;
118 double cosSqAlpha = 0.0;
119 double cos2SM = 0.0;
120 double cosSigma = 0.0;
121 double sinSigma = 0.0;
122 double cosLambda = 0.0;
123 double sinLambda = 0.0;
124
125 double lambda = L; // initial guess
126 for (int iter = 0; iter < MAXITERS; iter++) {
127 double lambdaOrig = lambda;
128 cosLambda = Math.cos(lambda);
129 sinLambda = Math.sin(lambda);
130 double t1 = cosU2 * sinLambda;
131 double t2 = cosU1 * sinU2 - sinU1 * cosU2 * cosLambda;
132 double sinSqSigma = t1 * t1 + t2 * t2; // (14)
133 sinSigma = Math.sqrt(sinSqSigma);
134 cosSigma = sinU1sinU2 + cosU1cosU2 * cosLambda; // (15)
135 sigma = Math.atan2(sinSigma, cosSigma); // (16)
136 double sinAlpha = (sinSigma == 0) ? 0.0 :
137 cosU1cosU2 * sinLambda / sinSigma; // (17)
138 cosSqAlpha = 1.0 - sinAlpha * sinAlpha;
139 cos2SM = (cosSqAlpha == 0) ? 0.0 :
140 cosSigma - 2.0 * sinU1sinU2 / cosSqAlpha; // (18)
141
142 double uSquared = cosSqAlpha * aSqMinusBSqOverBSq; // defn
143 A = 1 + (uSquared / 16384.0) * // (3)
144 (4096.0 + uSquared *
145 (-768 + uSquared * (320.0 - 175.0 * uSquared)));
146 double B = (uSquared / 1024.0) * // (4)
147 (256.0 + uSquared *
148 (-128.0 + uSquared * (74.0 - 47.0 * uSquared)));
149 double C = (f / 16.0) *
150 cosSqAlpha *
151 (4.0 + f * (4.0 - 3.0 * cosSqAlpha)); // (10)
152 double cos2SMSq = cos2SM * cos2SM;
153 deltaSigma = B * sinSigma * // (6)
154 (cos2SM + (B / 4.0) *
155 (cosSigma * (-1.0 + 2.0 * cos2SMSq) -
156 (B / 6.0) * cos2SM *
157 (-3.0 + 4.0 * sinSigma * sinSigma) *
158 (-3.0 + 4.0 * cos2SMSq)));
159
160 lambda = L +
161 (1.0 - C) * f * sinAlpha *
162 (sigma + C * sinSigma *
163 (cos2SM + C * cosSigma *
164 (-1.0 + 2.0 * cos2SM * cos2SM))); // (11)
165
166 double delta = (lambda - lambdaOrig) / lambda;
167 if (Math.abs(delta) < 1.0e-12) {
168 break;
169 }
170 }
171
172 float distance = (float) (b * A * (sigma - deltaSigma));
173 results[0] = distance;
174 if (results.length > 1) {
175 float initialBearing = (float) Math.atan2(cosU2 * sinLambda,
176 cosU1 * sinU2 - sinU1 * cosU2 * cosLambda);
177 initialBearing *= 180.0 / Math.PI;
178 results[1] = initialBearing;
179 if (results.length > 2) {
180 float finalBearing = (float) Math.atan2(cosU1 * sinLambda,
181 -sinU1 * cosU2 + cosU1 * sinU2 * cosLambda);
182 finalBearing *= 180.0 / Math.PI;
183 results[2] = finalBearing;
184 }
185 }
186 }
187
188 /**
189 * Computes the approximate distance in meters between two
190 * locations, and optionally the initial and final bearings of the
191 * shortest path between them. Distance and bearing are defined using the
192 * WGS84 ellipsoid.
193 *
194 * <p> The computed distance is stored in results[0]. If results has length
195 * 2 or greater, the initial bearing is stored in results[1]. If results has
196 * length 3 or greater, the final bearing is stored in results[2].
197 *
198 * @param startLatitude the starting latitude
199 * @param startLongitude the starting longitude
200 * @param endLatitude the ending latitude
201 * @param endLongitude the ending longitude
202 * @param results an array of floats to hold the results
203 *
204 * @throws IllegalArgumentException if results is null or has length < 1
205 */
206 public static void distanceBetween(double startLatitude, double startLongitude,
207 double endLatitude, double endLongitude, float[] results) {
208 if (results == null || results.length < 1) {
209 throw new IllegalArgumentException("results is null or has length < 1");
210 }
211 computeDistanceAndBearing(startLatitude, startLongitude,
212 endLatitude, endLongitude, results);
213 }
214
215 }

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