Distance between geopoints

Question

I have a problem calculating the distance between two geopoints.

The geopoints are:

position1 = mapView.getProjection().fromPixels(
(int) e.getX(),
(int) e.getY());

and the other one

double lat = 35.1064;
double lng = 22.556412;
GeoPoint position2 = new GeoPoint((int)(lat * 1E6), (int)(lng * 1E6));

Then I create two locations:

Location loc = new Location("");                                

loc.setLatitude(position1.getLatitudeE6());

loc.setLongitude(position1.getLongitudeE6());

Location loc2 = new Location("");                               

loc.setLatitude(position2.getLatitudeE6());

loc.setLongitude(position2.getLongitudeE6());

And then I calculate the distance:

float distance = loc.distanceTo(loc2);

and I round it:

Math.round(distance);

But I get results like:

1.4331783E7

What am I doing wrong?

Cause the distance should be in meters and the point i set and i tap is max 100 meters far so i think its not the result i need! — user878813, Jan 04 '12 at 11:15
Check out this link http://www.codecodex.com/wiki/Calculate_Distance_Between_Two_Points_on_a_Globe — Dany's, Jan 04 '12 at 10:45

score 11 · Accepted Answer · answered Jan 04 '12 at 10:31

try following my method,

    /**
 * 
 * @param lat1 Latitude of the First Location
 * @param lng1 Logitude of the First Location
 * @param lat2 Latitude of the Second Location
 * @param lng2 Longitude of the Second Location
 * @return distance between two lat-lon in float format
 */

public static float distFrom (float lat1, float lng1, float lat2, float lng2 ) 
{
    double earthRadius = 3958.75;
    double dLat = Math.toRadians(lat2-lat1);
    double dLng = Math.toRadians(lng2-lng1);
    double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
    Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
    Math.sin(dLng/2) * Math.sin(dLng/2);
    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
    double dist = earthRadius * c;

    int meterConversion = 1609;

    return new Float(dist * meterConversion).floatValue();
}

score 1 · Answer 2 · answered Jan 04 '12 at 11:38

You are taking wrong latitude and longitudes, please replace the following lines

Location loc = new Location("");                                

loc.setLatitude(position1.getLatitudeE6());

loc.setLongitude(position1.getLongitudeE6());

Location loc2 = new Location("");                               

loc.setLatitude(position2.getLatitudeE6());

loc.setLongitude(position2.getLongitudeE6());

with

Location loc = new Location("");                                

loc.setLatitude(position1.getLatitudeE6()/1E6);

loc.setLongitude(position1.getLongitudeE6()/1E6);

Location loc2 = new Location("");                               

loc.setLatitude(position2.getLatitudeE6()/1E6);

loc.setLongitude(position2.getLongitudeE6()/1E6);

and then once, you will get correct answer.

Pratik · Answer 3 · 2012-01-04T10:46:51.363

0

you are set the GeoPoint value into the Location object instead of double value try to set as double value of Latitude and Longitude

Location loc = new Location("");                                

loc.setLatitude(35.1064);

loc.setLongitude(22.556412);

Location loc2 = new Location("");                               

loc2.setLatitude(22.556412);

loc2.setLongitude(35.1064);

now get the location

float distance = loc.distanceTo(loc2);

edited Jan 04 '12 at 10:46

answered Jan 04 '12 at 10:38

Pratik

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I cannot set both of the values as pure numbers because the first geopoint is produced according to the place of the map the user taps. – user878813 Jan 04 '12 at 10:42
whatever I just give the example by passing the value in double format, you can pass the geopoint value by dividing them using 1e6 value like loc.setLatitude(position1.getLatitudeE6()/1E6) and one another thing is you didn't set the lat/lng value for loc2 object you just change the the loc value – Pratik Jan 04 '12 at 10:46

Distance between geopoints

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