Calculates distance between two points specified by latitude/longitude - Java java.lang

Java examples for java.lang:Math Geometry Distance

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Description

Calculates distance between two points specified by latitude/longitude

Demo Code


//package com.java2s;

public class Main {


    /**//from w ww  .  j  a va 2  s  .  c o  m
     * Calculates geodetic distance between two points specified by latitude/longitude using Vincenty inverse formula
     * for ellipsoids
     * 
     * @param lat1
     *            first point latitude in decimal degrees
     * @param lon1
     *            first point longitude in decimal degrees
     * @param lat2
     *            second point latitude in decimal degrees
     * @param lon2
     *            second point longitude in decimal degrees
     * @returns distance in meters between points with 5.10<sup>-4</sup> precision
     * @see <a href="http://www.movable-type.co.uk/scripts/latlong-vincenty.html">Originally posted here</a>
     */
    public static double distVincenty(double lat1, double lon1,
            double lat2, double lon2) {
        double a = 6378137, b = 6356752.314245, f = 1 / 298.257223563; // WGS-84 ellipsoid params
        double L = Math.toRadians(lon2 - lon1);
        double U1 = Math.atan((1 - f) * Math.tan(Math.toRadians(lat1)));
        double U2 = Math.atan((1 - f) * Math.tan(Math.toRadians(lat2)));
        double sinU1 = Math.sin(U1), cosU1 = Math.cos(U1);
        double sinU2 = Math.sin(U2), cosU2 = Math.cos(U2);

        double sinLambda, cosLambda, sinSigma, cosSigma, sigma, sinAlpha, cosSqAlpha, cos2SigmaM;
        double lambda = L, lambdaP, iterLimit = 100;
        do {
            sinLambda = Math.sin(lambda);
            cosLambda = Math.cos(lambda);
            sinSigma = Math.sqrt((cosU2 * sinLambda) * (cosU2 * sinLambda)
                    + (cosU1 * sinU2 - sinU1 * cosU2 * cosLambda)
                    * (cosU1 * sinU2 - sinU1 * cosU2 * cosLambda));
            if (sinSigma == 0)
                return 0; // co-incident points
            cosSigma = sinU1 * sinU2 + cosU1 * cosU2 * cosLambda;
            sigma = Math.atan2(sinSigma, cosSigma);
            sinAlpha = cosU1 * cosU2 * sinLambda / sinSigma;
            cosSqAlpha = 1 - sinAlpha * sinAlpha;
            cos2SigmaM = cosSigma - 2 * sinU1 * sinU2 / cosSqAlpha;
            if (Double.isNaN(cos2SigmaM))
                cos2SigmaM = 0; // equatorial line: cosSqAlpha=0 (?6)
            double C = f / 16 * cosSqAlpha * (4 + f * (4 - 3 * cosSqAlpha));
            lambdaP = lambda;
            lambda = L
                    + (1 - C)
                    * f
                    * sinAlpha
                    * (sigma + C
                            * sinSigma
                            * (cos2SigmaM + C * cosSigma
                                    * (-1 + 2 * cos2SigmaM * cos2SigmaM)));
        } while (Math.abs(lambda - lambdaP) > 1e-12 && --iterLimit > 0);

        if (iterLimit == 0)
            return 9999999; // formula failed to converge

        double uSq = cosSqAlpha * (a * a - b * b) / (b * b);
        double A = 1 + uSq / 16384
                * (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
        double B = uSq / 1024
                * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));
        double deltaSigma = B
                * sinSigma
                * (cos2SigmaM + B
                        / 4
                        * (cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM) - B
                                / 6
                                * cos2SigmaM
                                * (-3 + 4 * sinSigma * sinSigma)
                                * (-3 + 4 * cos2SigmaM * cos2SigmaM)));
        double dist = b * A * (sigma - deltaSigma);

        return dist;
    }
}

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