add great circle distance calc

jsprit-core/src/main/java/jsprit/core/util/GreatCircleDistanceCalculator.java

@@ -0,0 +1,55 @@
+/*******************************************************************************
+ * Copyright (C) 2014  Stefan Schroeder
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.0 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ ******************************************************************************/
+
+package jsprit.core.util;
+
+/**
+ * Created by schroeder on 28.11.14.
+ */
+public class GreatCircleDistanceCalculator {
+
+    private static final double R = 6372.8; // km
+
+    /**
+     * Harversine method.
+     *
+     * double lon1 = coord1.getX();
+     * double lon2 = coord2.getX();
+     * double lat1 = coord1.getY();
+     * double lat2 = coord2.getY();
+     *
+     * @param coord1 - from coord
+     * @param coord2 - to coord
+     * @return great circle distance
+     */
+    public  static double calculateDistance(Coordinate coord1, Coordinate coord2){
+        double lon1 = coord1.getX();
+        double lon2 = coord2.getX();
+        double lat1 = coord1.getY();
+        double lat2 = coord2.getY();
+
+        double delta_Lat = Math.toRadians(lat2 - lat1);
+        double delta_Lon = Math.toRadians(lon2 - lon1);
+        lat1 = Math.toRadians(lat1);
+        lat2 = Math.toRadians(lat2);
+
+        double a = Math.sin(delta_Lat / 2) * Math.sin(delta_Lat / 2) + Math.sin(delta_Lon / 2) * Math.sin(delta_Lon / 2) * Math.cos(lat1) * Math.cos(lat2);
+        double c = 2 * Math.asin(Math.sqrt(a));
+        return R * c;
+    }
+
+}

jsprit-core/src/main/java/jsprit/core/util/ManhattanDistanceCalculator.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (C) 2013  Stefan Schroeder
+ * Copyright (C) 2014  Stefan Schroeder
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -21,9 +21,8 @@ package jsprit.core.util;
 public class ManhattanDistanceCalculator {
 
 	public static double calculateDistance(Coordinate coord1, Coordinate coord2) {
-		double distance = Math.abs(coord1.getX() - coord2.getX())
+		return Math.abs(coord1.getX() - coord2.getX())
 				+ Math.abs(coord1.getY() - coord2.getY());
-		return distance;
 	}
 
 }

jsprit-core/src/test/java/jsprit/core/util/GreatCircleDistanceCalculatorTest.java

@@ -0,0 +1,44 @@
+/*******************************************************************************
+ * Copyright (C) 2014  Stefan Schroeder
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3.0 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ ******************************************************************************/
+
+package jsprit.core.util;
+
+import junit.framework.Assert;
+import org.junit.Test;
+
+/**
+ * Created by schroeder on 28.11.14.
+ */
+public class GreatCircleDistanceCalculatorTest {
+
+    @Test
+    public void test(){
+        double lon1 = 8.3858333;
+        double lat1 = 49.0047222;
+
+        double lon2 = 12.1333333;
+        double lat2 = 54.0833333;
+
+        double greatCircle = GreatCircleDistanceCalculator.calculateDistance(
+                Coordinate.newInstance(lon1,lat1),
+                Coordinate.newInstance(lon2,lat2)
+        );
+        Assert.assertEquals(600,greatCircle,30.);
+    }
+
+
+}