Mercurial > dive4elements > gnv-client
diff gnv-artifacts/src/main/java/de/intevation/gnv/utils/DistanceCalculator.java @ 657:af3f56758f59
merged gnv-artifacts/0.5
author | Thomas Arendsen Hein <thomas@intevation.de> |
---|---|
date | Fri, 28 Sep 2012 12:13:53 +0200 |
parents | 1ab23cd66870 |
children | 9a828e5a2390 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gnv-artifacts/src/main/java/de/intevation/gnv/utils/DistanceCalculator.java Fri Sep 28 12:13:53 2012 +0200 @@ -0,0 +1,84 @@ +/** + * + */ +package de.intevation.gnv.utils; + +import com.vividsolutions.jts.geom.Point; +import com.vividsolutions.jts.geom.Coordinate; + +import java.util.List; + +/** + * @author Tim Englich <tim.englich@intevation.de> + * + */ +public class DistanceCalculator { + + private final static double flattening = 1.0 / 298.257233563; + + private final static double earthRadius = 6378137.0 / 1000.0 ; + + /** + * Constructor + */ + public DistanceCalculator() { + } + + public static double calculateDistance(Point p1, Point p2){ + return calculateDistance(p1.getCoordinate(), p2.getCoordinate()); + } + + public static double calculateDistance(Coordinate p1, Coordinate p2){ + double resultValue = 0.0; + + double b1 = p1.y; + double b2 = p2.y; + + double l1 = p1.x; + double l2 = p2.x; + + + double F = (b1 + b2) / 2.0; + double G = (b1 - b2) / 2.0; + double l = (l1 - l2) / 2.0; + + F = (Math.PI / 180.0) * F; + G = (Math.PI / 180.0) * G; + l = (Math.PI / 180.0) * l; + + double S = ((Math.sin(G) * Math.sin(G)) * ((Math.cos(l) * Math.cos(l))))+ + ((Math.cos(F) * Math.cos(F)) * ((Math.sin(l) * Math.sin(l)))); + + double C = ((Math.cos(G) * Math.cos(G)) * ((Math.cos(l) * Math.cos(l))))+ + ((Math.sin(F) * Math.sin(F)) * ((Math.sin(l) * Math.sin(l)))); + + double w = Math.atan(Math.sqrt((S/C))); + + double D = 2.0 * w * earthRadius; + + double R = Math.sqrt((S*C)) / w; + + double H1 = (3.0 * R - 1.0 ) / (2.0 * C); + double H2 = (3.0 * R + 1.0 ) / (2.0 * S); + + resultValue = D * (1 + (flattening * H1 * (Math.sin(F) * Math.sin(F)) * + (Math.cos(G) * Math.cos(G))) - + (flattening * H2 * (Math.cos(F) * Math.cos(F)) * + (Math.sin(G) * Math.sin(G)))); + + return resultValue; + } + + public static final double calculateDistance(List<Coordinate> path) { + int N = path.size(); + if (N < 2) { + return 0d; + } + double sum = 0d; + for (int i = 1; i < N; ++i) { + sum += calculateDistance(path.get(i-1), path.get(i)); + } + return sum; + } + +}