Calculate distance between two GPS points.

Haversine distance.java

/**
	 * Calculate distance between two gps points based in Haversine formula: http://en.wikipedia.org/wiki/Haversine_formula
	 * 
	 * @param latitude1 GPS point 1 Latitude
	 * @param longitude1 GPS point 1 Longitude
	 * @param latitude2 GPS point 2 Latitude
	 * @param longitude2 GPS point 1 Longitude
	 * @return Distance in kilometers (km)
	 */
	static double haversineDistance(float latitude1, float longitude1, float latitude2, float longitude2)
	{
		double h = (1 - Math.cos(latitude1 * Math.PI / 180 - latitude2 * Math.PI / 180)) / 2 + Math.cos(latitude2 * Math.PI / 180) * Math.cos(latitude1 * Math.PI / 180) * (1 - Math.cos(longitude1 * Math.PI / 180 - longitude2 * Math.PI / 180)) / 2;
		
		h += 2 * 6367.45 * Math.asin(Math.sqrt(h));
		
		return h;
	}

haversine_distance.py

import numpy as np


def haversine_np(lon1, lat1, lon2, lat2):
    """
    Calculate the great circle distance between two points
    on the earth (specified in decimal degrees)

    All args must be of equal length.    

    """
    lon1, lat1, lon2, lat2 = map(np.radians, [lon1, lat1, lon2, lat2])

    dlon = lon2 - lon1
    dlat = lat2 - lat1

    a = np.sin(dlat/2.0)**2 + np.cos(lat1) * np.cos(lat2) * np.sin(dlon/2.0)**2

    c = 2 * np.arcsin(np.sqrt(a))
    km = 6367 * c
    return km