| Distance.java |
1 /**
2 * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20 * SOFTWARE.
21 */
22
23 package com.liferay.util;
24
25 /**
26 * <a href="Distance.java.html"><b><i>View Source</i></b></a>
27 *
28 * @author Brian Wing Shun Chan
29 *
30 */
31 public class Distance {
32
33 public static double calculate(double lat1, double lon1,
34 double lat2, double lon2) {
35
36 // Convert from radians to degrees
37
38 lat1 = (Math.PI * lat1) / 180;
39 lon1 = (Math.PI * lon1) / 180;
40 lat2 = (Math.PI * lat2) / 180;
41 lon2 = (Math.PI * lon2) / 180;
42
43 double miles =
44 3963.4 *
45 Math.acos(
46 (Math.sin(lat1) * Math.sin(lat2)) +
47 (Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2)));
48
49 return miles;
50 }
51
52 public static double kmToMiles(double km) {
53 return km * 0.621;
54 }
55
56 public static double milesToKm(double miles) {
57 return miles / 0.621;
58 }
59
60 }