android

latitude-longitude

location

distance

please shed some light on this situation

Right now i have two array having latitude and longitude of nearby places and also have the user location latiude and longiude now i want to calculate the distance between user location and nearby places and want to show them in listview.

I know that there is a method for calculating distance as

public static void distanceBetween (double startLatitude, double startLongitude, double endLatitude, double endLongitude, float[] results);

Now what is the problem is how to pass these two array having nearby latitude and longitue in this method and get the array of distances.

Solution 1

http://developer.android.com/reference/android/location/Location.html

Look into distanceTo

Returns the approximate distance in meters between this location and the given location. Distance is defined using the WGS84 ellipsoid.

or distanceBetween

Computes the approximate distance in meters between two locations, and optionally the initial and final bearings of the shortest path between them. Distance and bearing are defined using the WGS84 ellipsoid.

You can create a Location object from a latitude and longitude:

Location locationA = new Location("point A");

locationA.setLatitude(latA);
locationA.setLongitude(lngA);

Location locationB = new Location("point B");

locationB.setLatitude(latB);
locationB.setLongitude(lngB);

float distance = locationA.distanceTo(locationB);

or

private double meterDistanceBetweenPoints(float lat_a, float lng_a, float lat_b, float lng_b) {
    float pk = (float) (180.f/Math.PI);

    float a1 = lat_a / pk;
    float a2 = lng_a / pk;
    float b1 = lat_b / pk;
    float b2 = lng_b / pk;

    double t1 = Math.cos(a1) * Math.cos(a2) * Math.cos(b1) * Math.cos(b2);
    double t2 = Math.cos(a1) * Math.sin(a2) * Math.cos(b1) * Math.sin(b2);
    double t3 = Math.sin(a1) * Math.sin(b1);
    double tt = Math.acos(t1 + t2 + t3);
   
    return 6366000 * tt;
}

Solution 2

Try This Code. here we have two longitude and latitude values and selected_location.distanceTo(near_locations) function returns the distance between those places in meters.

Location selected_location = new Location("locationA");
            selected_location.setLatitude(17.372102);
            selected_location.setLongitude(78.484196);
Location near_locations = new Location("locationB");
            near_locations.setLatitude(17.375775);
            near_locations.setLongitude(78.469218);
double distance = selected_location.distanceTo(near_locations);

here "distance" is distance between locationA & locationB (in Meters)

Solution 3

There is only one user Location, so you can iterate List of nearby places can call the distanceTo() function to get the distance, you can store in an array if you like.

From what I understand, distanceBetween() is for far away places, it's output is a WGS84 ellipsoid.

Solution 4

    private static Double _MilesToKilometers = 1.609344;
    private static Double _MilesToNautical = 0.8684;


    /// <summary>
    /// Calculates the distance between two points of latitude and longitude.
    /// Great Link - http://www.movable-type.co.uk/scripts/latlong.html
    /// </summary>
    /// <param name="coordinate1">First coordinate.</param>
    /// <param name="coordinate2">Second coordinate.</param>
    /// <param name="unitsOfLength">Sets the return value unit of length.</param>
    public static Double Distance(Coordinate coordinate1, Coordinate coordinate2, UnitsOfLength unitsOfLength)
    {

        double theta = coordinate1.getLongitude() - coordinate2.getLongitude();
        double distance = Math.sin(ToRadian(coordinate1.getLatitude())) * Math.sin(ToRadian(coordinate2.getLatitude())) +
                       Math.cos(ToRadian(coordinate1.getLatitude())) * Math.cos(ToRadian(coordinate2.getLatitude())) *
                       Math.cos(ToRadian(theta));

        distance = Math.acos(distance);
        distance = ToDegree(distance);
        distance = distance * 60 * 1.1515;

        if (unitsOfLength == UnitsOfLength.Kilometer)
            distance = distance * _MilesToKilometers;
        else if (unitsOfLength == UnitsOfLength.NauticalMiles)
            distance = distance * _MilesToNautical;

        return (distance);

    }

Solution 5

distanceTo will give you the distance in meters between the two given location ej target.distanceTo(destination).

distanceBetween give you the distance also but it will store the distance in a array of float( results[0]). the doc says If results has length 2 or greater, the initial bearing is stored in results[1]. If results has length 3 or greater, the final bearing is stored in results[2]

hope that this helps

i've used distanceTo to get the distance from point A to B i think that is the way to go.

Solution 6

public double distance(Double latitude, Double longitude, double e, double f) {
        double d2r = Math.PI / 180;

        double dlong = (longitude - f) * d2r;
        double dlat = (latitude - e) * d2r;
        double a = Math.pow(Math.sin(dlat / 2.0), 2) + Math.cos(e * d2r)
                * Math.cos(latitude * d2r) * Math.pow(Math.sin(dlong / 2.0), 2)
        double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
        double d = 6367 * c;
                return d;

    }

Solution 7

I wanted to implement myself this, i ended up reading the Wikipedia page on Great-circle distance formula, because no code was readable enough for me to use as basis.

C# example

    /// <summary>
    /// Calculates the distance between two locations using the Great Circle Distance algorithm
    /// <see cref="https://en.wikipedia.org/wiki/Great-circle_distance"/>
    /// </summary>
    /// <param name="first"></param>
    /// <param name="second"></param>
    /// <returns></returns>
    private static double DistanceBetween(GeoLocation first, GeoLocation second)
    {
        double longitudeDifferenceInRadians = Math.Abs(ToRadians(first.Longitude) - ToRadians(second.Longitude));

        double centralAngleBetweenLocationsInRadians = Math.Acos(
            Math.Sin(ToRadians(first.Latitude)) * Math.Sin(ToRadians(second.Latitude)) +
            Math.Cos(ToRadians(first.Latitude)) * Math.Cos(ToRadians(second.Latitude)) *
            Math.Cos(longitudeDifferenceInRadians));

        const double earthRadiusInMeters = 6357 * 1000;

        return earthRadiusInMeters * centralAngleBetweenLocationsInRadians;
    }

    private static double ToRadians(double degrees)
    {
        return degrees * Math.PI / 180;
    }