Sample Code (C#)
01 | using System; |
02 | //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
03 | //::: ::: |
04 | //::: This routine calculates the distance between two points (given the ::: |
05 | //::: latitude/longitude of those points). It is being used to calculate ::: |
06 | //::: the distance between two locations using GeoDataSource(TM) products ::: |
07 | //::: ::: |
08 | //::: Definitions: ::: |
09 | //::: South latitudes are negative, east longitudes are positive ::: |
10 | //::: ::: |
11 | //::: Passed to function: ::: |
12 | //::: lat1, lon1 = Latitude and Longitude of point 1 (in decimal degrees) ::: |
13 | //::: lat2, lon2 = Latitude and Longitude of point 2 (in decimal degrees) ::: |
14 | //::: unit = the unit you desire for results ::: |
15 | //::: where: 'M' is statute miles ::: |
16 | //::: 'K' is kilometers (default) ::: |
17 | //::: 'N' is nautical miles ::: |
18 | //::: ::: |
19 | //::: Worldwide cities and other features databases with latitude longitude ::: |
20 | //::: are available at http://www.geodatasource.com ::: |
21 | //::: ::: |
22 | //::: For enquiries, please contact sales@geodatasource.com ::: |
23 | //::: ::: |
24 | //::: Official Web site: http://www.geodatasource.com ::: |
25 | //::: ::: |
26 | //::: GeoDataSource.com (C) All Rights Reserved 2014 ::: |
27 | //::: ::: |
28 | //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
29 |
30 | private double distance(double lat1, double lon1, double lat2, double lon2, char unit) { |
31 | double theta = lon1 - lon2; |
32 | double dist = Math.Sin(deg2rad(lat1)) * Math.Sin(deg2rad(lat2)) + Math.Cos(deg2rad(lat1)) * Math.Cos(deg2rad(lat2)) * Math.Cos(deg2rad(theta)); |
33 | dist = Math.Acos(dist); |
34 | dist = rad2deg(dist); |
35 | dist = dist * 60 * 1.1515; |
36 | if (unit == 'K') { |
37 | dist = dist * 1.609344; |
38 | } else if (unit == 'N') { |
39 | dist = dist * 0.8684; |
40 | } |
41 | return (dist); |
42 | } |
43 |
44 | //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
45 | //:: This function converts decimal degrees to radians ::: |
46 | //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
47 | private double deg2rad(double deg) { |
48 | return (deg * Math.PI / 180.0); |
49 | } |
50 |
51 | //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
52 | //:: This function converts radians to decimal degrees ::: |
53 | //::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: |
54 | private double rad2deg(double rad) { |
55 | return (rad / Math.PI * 180.0); |
56 | } |
57 |
58 | Console.WriteLine(distance(32.9697, -96.80322, 29.46786, -98.53506, "M")); |
59 | Console.WriteLine(distance(32.9697, -96.80322, 29.46786, -98.53506, "K")); |
60 | Console.WriteLine(distance(32.9697, -96.80322, 29.46786, -98.53506, "N")); |
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