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

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Revision 2577 - (hide annotations) (download)
Thu Jun 11 20:10:23 2015 UTC (8 years, 11 months ago) by torben
File size: 6718 byte(s)
add new distance calculator
1 torben 2211 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     public static double beregnAfstand(GeoPoint point1, GeoPoint point2) {
17     //(62.8*sqrt(3.1*(Power(a.Latitude-x.Latitude,2)+Power(a.Longitude-x.Longitude,2)))) as Afstand,
18    
19    
20     double pwrLat = Math.pow(point1.latitude - point2.latitude, 2);
21     double pwrLng = Math.pow(point1.longitude - point2.longitude, 2);
22    
23     return 62.8 * Math.sqrt( 3.1 * (pwrLat + pwrLng) );
24     }
25 torben 2577
26     public static float beregnAfstand2(GeoPoint p1, GeoPoint p2) {
27     float[] result = new float[1];
28    
29    
30     computeDistanceAndBearing(p1.latitude, p1.longitude, p2.latitude, p2.longitude, result);
31    
32     return result[0];
33     }
34 torben 2222
35    
36     //Latitude (horizonal), longitude(vertical) so
37     // 1 degree latitude is ~ 111320 meters, since the distance between the horizonal lines is always the same
38     // 1 degree longitude is ~111320 meters at equator but gets shorter as we get closer to the poles.
39     // so 1 degree longitude is 64.5 km at denmarks southern point (gedser=54.55,11.95)
40     // and is 59.4km at northern point (skagen = 57.75,10.65)
41    
42     public static double kmToLatitude(double km) {
43     return km / 111.320 ;
44     }
45    
46     public static double kmToLongitude( double km) {//denne er kun ca
47     return km / 62.0;
48     }
49 torben 2577
50    
51    
52     //Kopieret fra android.location.Location
53     private static void computeDistanceAndBearing(double lat1, double lon1,
54     double lat2, double lon2, float[] results) {
55     // Based on http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
56     // using the "Inverse Formula" (section 4)
57    
58     int MAXITERS = 20;
59     // Convert lat/long to radians
60     lat1 *= Math.PI / 180.0;
61     lat2 *= Math.PI / 180.0;
62     lon1 *= Math.PI / 180.0;
63     lon2 *= Math.PI / 180.0;
64    
65     double a = 6378137.0; // WGS84 major axis
66     double b = 6356752.3142; // WGS84 semi-major axis
67     double f = (a - b) / a;
68     double aSqMinusBSqOverBSq = (a * a - b * b) / (b * b);
69    
70     double L = lon2 - lon1;
71     double A = 0.0;
72     double U1 = Math.atan((1.0 - f) * Math.tan(lat1));
73     double U2 = Math.atan((1.0 - f) * Math.tan(lat2));
74    
75     double cosU1 = Math.cos(U1);
76     double cosU2 = Math.cos(U2);
77     double sinU1 = Math.sin(U1);
78     double sinU2 = Math.sin(U2);
79     double cosU1cosU2 = cosU1 * cosU2;
80     double sinU1sinU2 = sinU1 * sinU2;
81    
82     double sigma = 0.0;
83     double deltaSigma = 0.0;
84     double cosSqAlpha = 0.0;
85     double cos2SM = 0.0;
86     double cosSigma = 0.0;
87     double sinSigma = 0.0;
88     double cosLambda = 0.0;
89     double sinLambda = 0.0;
90    
91     double lambda = L; // initial guess
92     for (int iter = 0; iter < MAXITERS; iter++) {
93     double lambdaOrig = lambda;
94     cosLambda = Math.cos(lambda);
95     sinLambda = Math.sin(lambda);
96     double t1 = cosU2 * sinLambda;
97     double t2 = cosU1 * sinU2 - sinU1 * cosU2 * cosLambda;
98     double sinSqSigma = t1 * t1 + t2 * t2; // (14)
99     sinSigma = Math.sqrt(sinSqSigma);
100     cosSigma = sinU1sinU2 + cosU1cosU2 * cosLambda; // (15)
101     sigma = Math.atan2(sinSigma, cosSigma); // (16)
102     double sinAlpha = (sinSigma == 0) ? 0.0 :
103     cosU1cosU2 * sinLambda / sinSigma; // (17)
104     cosSqAlpha = 1.0 - sinAlpha * sinAlpha;
105     cos2SM = (cosSqAlpha == 0) ? 0.0 :
106     cosSigma - 2.0 * sinU1sinU2 / cosSqAlpha; // (18)
107    
108     double uSquared = cosSqAlpha * aSqMinusBSqOverBSq; // defn
109     A = 1 + (uSquared / 16384.0) * // (3)
110     (4096.0 + uSquared *
111     (-768 + uSquared * (320.0 - 175.0 * uSquared)));
112     double B = (uSquared / 1024.0) * // (4)
113     (256.0 + uSquared *
114     (-128.0 + uSquared * (74.0 - 47.0 * uSquared)));
115     double C = (f / 16.0) *
116     cosSqAlpha *
117     (4.0 + f * (4.0 - 3.0 * cosSqAlpha)); // (10)
118     double cos2SMSq = cos2SM * cos2SM;
119     deltaSigma = B * sinSigma * // (6)
120     (cos2SM + (B / 4.0) *
121     (cosSigma * (-1.0 + 2.0 * cos2SMSq) -
122     (B / 6.0) * cos2SM *
123     (-3.0 + 4.0 * sinSigma * sinSigma) *
124     (-3.0 + 4.0 * cos2SMSq)));
125    
126     lambda = L +
127     (1.0 - C) * f * sinAlpha *
128     (sigma + C * sinSigma *
129     (cos2SM + C * cosSigma *
130     (-1.0 + 2.0 * cos2SM * cos2SM))); // (11)
131    
132     double delta = (lambda - lambdaOrig) / lambda;
133     if (Math.abs(delta) < 1.0e-12) {
134     break;
135     }
136     }
137    
138     float distance = (float) (b * A * (sigma - deltaSigma));
139     results[0] = distance;
140     if (results.length > 1) {
141     float initialBearing = (float) Math.atan2(cosU2 * sinLambda,
142     cosU1 * sinU2 - sinU1 * cosU2 * cosLambda);
143     initialBearing *= 180.0 / Math.PI;
144     results[1] = initialBearing;
145     if (results.length > 2) {
146     float finalBearing = (float) Math.atan2(cosU1 * sinLambda,
147     -sinU1 * cosU2 + cosU1 * sinU2 * cosLambda);
148     finalBearing *= 180.0 / Math.PI;
149     results[2] = finalBearing;
150     }
151     }
152     }
153    
154     /**
155     * Computes the approximate distance in meters between two
156     * locations, and optionally the initial and final bearings of the
157     * shortest path between them. Distance and bearing are defined using the
158     * WGS84 ellipsoid.
159     *
160     * <p> The computed distance is stored in results[0]. If results has length
161     * 2 or greater, the initial bearing is stored in results[1]. If results has
162     * length 3 or greater, the final bearing is stored in results[2].
163     *
164     * @param startLatitude the starting latitude
165     * @param startLongitude the starting longitude
166     * @param endLatitude the ending latitude
167     * @param endLongitude the ending longitude
168     * @param results an array of floats to hold the results
169     *
170     * @throws IllegalArgumentException if results is null or has length < 1
171     */
172     public static void distanceBetween(double startLatitude, double startLongitude,
173     double endLatitude, double endLongitude, float[] results) {
174     if (results == null || results.length < 1) {
175     throw new IllegalArgumentException("results is null or has length < 1");
176     }
177     computeDistanceAndBearing(startLatitude, startLongitude,
178     endLatitude, endLongitude, results);
179     }
180    
181 torben 2211 }

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