Distance between points

Question

I'm trying to create a function so that I return the distance between various points on the map, based on where I am and the rest of the points.

But so can get the distance obtained at the first point of the database.

Could you help me?

if (cursor.getCount() > 0) {
    if (cursor != null && cursor.moveToFirst()) {       
        lat_s = >cursor.getString(cursor.getColumnIndex("latitude"));
        lng_s = >cursor.getString(cursor.getColumnIndex("longitude"));          
        lat_p = Double.parseDouble(lat_s);
        lng_p = Double.parseDouble(lng_s);          
        double dist = getDistancia(lat, lng, lat_p, lng_p);         
    }       
    @SuppressWarnings("deprecation")        
    SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(this,
        R.layout.list_row, cursor, from, to);       
    listView.setAdapter(mAdapter);  
}

and the function to return me the distance is:

public double getDistancia(double latitude, double longitude, 
        double latitudePto, double longitudePto){  
    double dlon, dlat, a, distancia;  
    dlon = longitudePto - longitude;  
    dlat = latitudePto - latitude;  
    a = Math.pow(Math.sin(dlat/2),2) + Math.cos(latitude) * 
            Math.cos(latitudePto) * Math.pow(Math.sin(dlon/2),2);  
    distancia = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));  
    return 6378140 * distancia; /* 6378140 is the radius of the Earth in meters*/  
}

I have already answered similar question on SO. Please check this link : http://stackoverflow.com/questions/19332850/calculate-shortest-path-between-two-geo-points/19355447#19355447 — arshu, Oct 14 '13 at 09:16
Have a look a [this][1] similar question. This has many helpful answers. [1]: http://stackoverflow.com/questions/19218081/how-to-calculate-distance-from-different-markers-in-a-map-and-then-pick-up-the-l — Aishvarya Jaiswal, Nov 26 '13 at 12:47

yuva ツ · Answer 1 · 2013-10-14T09:07:49.470

1

Google map has provided api for getting distance between two Locations-

For more details

https://developers.google.com/maps/documentation/directions/

You can also use this-

Location locationA = new Location("point A");  
locationA.setLatitude(mLatitude / 1E6);  
locationA.setLongitude(mLongitude / 1E6);  
Location locationB = new Location("point B");  
locationB.setLatitude(lat / 1E6);  
locationB.setLongitude(lng / 1E6);  
double distance = locationA.distanceTo(locationB);

edited Oct 14 '13 at 09:07

answered Oct 14 '13 at 08:48

yuva ツ

3,707
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my question is how can I make several points, alert by "cursor", since it already tried to get an array but could not, the distance between two points is already, but I was among many. – Vitor Pereira Oct 14 '13 at 09:14
you can store your locations latitude and longitude in arraylist and then pass them in loop to google api(https://developers.google.com/maps/documentation/directions/ ).using json parsing you can get one by one. – yuva ツ Oct 14 '13 at 09:23

score 0 · Answer 2 · answered Oct 14 '13 at 08:34

Don't understand the question but here is an element of solution :

protected double distanceBetween(float lat_a, float lng_a, float lat_b, float lng_b) {

    float pk = (float) (180 / 3.14169);
    float a1 = lat_a / pk;
    float a2 = lng_a / pk;
    float b1 = lat_b / pk;
    float b2 = lng_b / pk;
    float t1 = FloatMath.cos(a1) * FloatMath.cos(a2) * FloatMath.cos(b1) * FloatMath.cos(b2);
    float t2 = FloatMath.cos(a1) * FloatMath.sin(a2) * FloatMath.cos(b1) * FloatMath.sin(b2);
    float t3 = FloatMath.sin(a1) * FloatMath.sin(b1);
    double tt = Math.acos(t1 + t2 + t3);
    return 6366000 * tt;
}

score 0 · Accepted Answer · answered Oct 14 '13 at 09:01

0

Check out this code, there are a few utils that could help you with this :)

https://github.com/BeyondAR/beyondar/blob/master/android/BeyondAR_Framework/src/com/beyondar/android/util/math/Distance.java

answered Oct 14 '13 at 09:01

Joan P.S

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Distance between points

3 Answers3