## Tuesday, December 4, 2007

### Solved Distance Calculation Puzzle !

When you check distance from you home to a store, to a restaurant, to a medical service provider and a big list - on their respective website. You will feel oh its hardly few miles from here. When you actually travel or try to find map from Yahoo, maps.google or mapquest - you will realize its not as near as it claimed on their website !! Is that a trick to attracts customers ?? I thought so until I came to know a better argument.

I am in process to implement "Distance Calculator" - that we used to see on websites. I found that all this calculators work on the basis of Latitude and Longitude. So thats in fact air distance between two places like from your home to a shop. Scientifically air distance would be shorter than road distance. A piece of Java code to calculate it :)

` import java.lang.Math;import java.lang.Double;public int calculateDistance(double latitudeA, double ``latitude``B, double longitudeA, double ``longitude``B){ double theDistance = (Math.sin(Math.toRadians(``latitude``A)) * Math.sin(Math.toRadians(``latitude``B)) + Math.cos(Math.toRadians(``latitude``A)) * Math.cos(Math.toRadians(``latitude``B)) * Math.cos(Math.toRadians(``longitude``A - ``longitude``B))); // Sin(laA)*Sin(laB) + Cos(laA)*Cos(laB)*Cos(loA-loB) return = (Math.toDegrees(Math.acos(theDistance))) * 69.09; //}`