| Distance.java |
1 /**
2 * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3 *
4 * The contents of this file are subject to the terms of the Liferay Enterprise
5 * Subscription License ("License"). You may not use this file except in
6 * compliance with the License. You can obtain a copy of the License by
7 * contacting Liferay, Inc. See the License for the specific language governing
8 * permissions and limitations under the License, including but not limited to
9 * distribution rights of the Software.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
12 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
13 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
14 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
15 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
17 * SOFTWARE.
18 */
19
20 package com.liferay.util;
21
22 /**
23 * <a href="Distance.java.html"><b><i>View Source</i></b></a>
24 *
25 * @author Brian Wing Shun Chan
26 *
27 */
28 public class Distance {
29
30 public static double calculate(double lat1, double lon1,
31 double lat2, double lon2) {
32
33 // Convert from radians to degrees
34
35 lat1 = (Math.PI * lat1) / 180;
36 lon1 = (Math.PI * lon1) / 180;
37 lat2 = (Math.PI * lat2) / 180;
38 lon2 = (Math.PI * lon2) / 180;
39
40 double miles =
41 3963.4 *
42 Math.acos(
43 (Math.sin(lat1) * Math.sin(lat2)) +
44 (Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2)));
45
46 return miles;
47 }
48
49 public static double kmToMiles(double km) {
50 return km * 0.621;
51 }
52
53 public static double milesToKm(double miles) {
54 return miles / 0.621;
55 }
56
57 }