/* -------------------------------------------------------------------------
OpenTripPlanner GWT Client
Copyright (C) 2015 Mecatran - info@mecatran.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
------------------------------------------------------------------------- */
package com.mecatran.otp.gwt.client.utils;
public class HaversineDistance {
private static final double EARTH_RADIUS = 6371 * 1000;
/**
* Compute the great-circle distance (Haversine distance) between two points
* on a globe.
*
* Approximation of the haversine formula, but much faster (use only one
* cosine and one square root). Works only if lat1 ~ lat2 and lon1 ~ lon2.
* Coordinates are given in decimal DEGREES.
*/
public static double computeHaversineDistance(double lat1, double lon1,
double lat2, double lon2) {
double dLat = Math.toRadians(lat2 - lat1);
double dLon = Math.toRadians(lon2 - lon1)
* Math.cos(Math.toRadians((lat1 + lat2) / 2));
return EARTH_RADIUS * Math.sqrt(dLat * dLat + dLon * dLon);
}
}