| Distance.java |
1 /**
2 * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3 *
4 *
5 *
6 *
7 * The contents of this file are subject to the terms of the Liferay Enterprise
8 * Subscription License ("License"). You may not use this file except in
9 * compliance with the License. You can obtain a copy of the License by
10 * contacting Liferay, Inc. See the License for the specific language governing
11 * permissions and limitations under the License, including but not limited to
12 * distribution rights 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 public class Distance {
31
32 public static double calculate(double lat1, double lon1,
33 double lat2, double lon2) {
34
35 // Convert from radians to degrees
36
37 lat1 = (Math.PI * lat1) / 180;
38 lon1 = (Math.PI * lon1) / 180;
39 lat2 = (Math.PI * lat2) / 180;
40 lon2 = (Math.PI * lon2) / 180;
41
42 double miles =
43 3963.4 *
44 Math.acos(
45 (Math.sin(lat1) * Math.sin(lat2)) +
46 (Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2)));
47
48 return miles;
49 }
50
51 public static double kmToMiles(double km) {
52 return km * 0.621;
53 }
54
55 public static double milesToKm(double miles) {
56 return miles / 0.621;
57 }
58
59 }