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Posted By

rnickel on 10/14/10


Tagged

j2me GPS blackberry


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How to calculate the distance between two lat/lon points on the blackberry

 / Published in: Java
 

URL: http://www.ryannickel.com/2010/10/how-to-calculate-the-distance-between-two-latlon-points-on-the-blackberry/

Yes, I realize that this won't work with j2me, but RIM has implemented some good helper classes to make this calculation much easier.

This calculation uses the Haversine formula.

Expand | Embed | Plain Text 
  1. public double calculateDistance(double lat1, double lon1, double lat2, double lon2)
  2.     {       
  3.         try{
  4.             double R = 6371; // km
  5.  
  6.             double dlat = Math.toRadians(lat2 - lat1);
  7.             double dlong = Math.toRadians(lon2 - lon1);
  8.  
  9.             double a = Math.sin(dlat / 2.0) * Math.sin(dlat / 2.0) +
  10.                         Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2))  *
  11.                         Math.sin(dlong / 2.0) * Math.sin(dlong / 2.0);
  12.             double num2 = Math.sqrt(a);
  13.             double num1 = Math.sqrt(1-a);
  14.             double c = 2 * MathUtilities.atan2(Math.sqrt(a), Math.sqrt(1-a));
  15.             double d = R * c;
  16.  
  17.             return d;
  18.  
  19.         } catch(Exception e){
  20.             e.printStackTrace();
  21.         }
  22.         return 0;
  23.     }

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Posted By: rnickel on October 14, 2010

You can disregard lines 12 and 13. They were put there for debug purposes and I forgot to remove them :D

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