Develop Reference

How to get covered distance by transit

I want to create an app in which I want to show how much distance does the user has been traveled.
I have tried using float distance = locationA.distanceTo(locationB); but it just draws a simple straight line from start to end and then calculates the distance.
I want to calculate the traveled distance based on the traveled route. Is it possible to do so using any Google maps API?

you just need service to continuously observer that user change it's location then you can use these function to calculate the distance.
public double GetDistanceInKm(double lat1, double lon1, double lat2, double lon2)
{
final int R = 6371;
// Radius of the earth in km
double dLat = deg2rad(lat2 - lat1);
// deg2rad below
double dLon = deg2rad(lon2 - lon1);
double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
double d = R * c;
// Distance in km
return d;
}
private double deg2rad(double deg)
{
return deg * (Math.PI / 180);
}

Assuming you have a bunch of lat long points making up a route. You have to take the distance from the previous point to the next point for all points and keep a total of that. In other words you need a-lot of lat lon data in between the route or you are just going to get a straight line.

You can use google maps api to get the distance
use this link to understand how to use it.

Get Latitude Longitude after x kilometer on Google Map without destination?

I am creating an Android app which requires finding a coordinate on the same route after X kilometers.
I have two coordinates x1,y1 & x2,y2 on a road. Now, my requirement is to find coordinate x3,y3 after some 3 kilometers (i.e., coordinate after x2,y2 not between x1,y1 & x2,y2) on the same road.
How can this be achieved ?

If you know the bearing, you can calculate the destination coordinate.
Sample Code:
private LatLng getDestinationPoint(LatLng source, double brng, double dist) {
dist = dist / 6371;
brng = Math.toRadians(brng);
double lat1 = Math.toRadians(source.latitude), lon1 = Math.toRadians(source.longitude);
double lat2 = Math.asin(Math.sin(lat1) * Math.cos(dist) +
Math.cos(lat1) * Math.sin(dist) * Math.cos(brng));
double lon2 = lon1 + Math.atan2(Math.sin(brng) * Math.sin(dist) *
Math.cos(lat1),
Math.cos(dist) - Math.sin(lat1) *
Math.sin(lat2));
if (Double.isNaN(lat2) || Double.isNaN(lon2)) {
return null;
}
return new LatLng(Math.toDegrees(lat2), Math.toDegrees(lon2));
}
Sample usage:
double radiusInKM = 10.0;
double bearing = 90;
LatLng destinationPoint = getDestinationPoint(new LatLng((25.48, -71.26), bearing, radiusInKM);
Or you can use heading between your pointA and pointB instead of bearing:
LatLng destinationPoint = getDestinationPoint(new LatLng(37.4038194,-122.081267), SphericalUtil.computeHeading(new LatLng(37.7577,-122.4376), new LatLng(37.4038194,-122.081267)), radiusInKM);
The SphericalUtil.computeHeading(p1, p2); method is from the Android Google Maps Utility library.
This is based on the Javascript method from this Stackoverflow answer.
If you want the point on same road, you might checkout this PHP answer.

Calculating distance travelled as the user moves

I need to calculate distance as the user moves in android. I have the starting point coordinates and can get the user's current location. How should I calculate distance.
I don't think I can call GoogleDistance Api as my application would be a real time application and calling this API would be extremely overhead or should calling GoogleDirectionsAPI would work fine.
Also I would like to test the distance travelled. How should I do it? Is there some way of sampling the data or do I really need to go out in the real world and actually travel and then test my application?
Edited: I want the distance travelled by the user and not the straight line distance between the points

I hope following will help:
In my app i started collecting lat longs after every 3fts (I set 3ft just for testing). I collected lat longs as follows:
Now I started calculating distance from point 1 to 2 and then 2 to 3 and then 3 to 4 and so on. After summing up I got total distance from 1 to 5.
I used following functions to calculate distance:
public double GetDistanceFromLatLonInKm(double lat1, double lon1, double lat2, double lon2)
{
final int R = 6371;
// Radius of the earth in km
double dLat = deg2rad(lat2 - lat1);
// deg2rad below
double dLon = deg2rad(lon2 - lon1);
double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(deg2rad(lat1)) * Math.cos(deg2rad(lat2)) * Math.sin(dLon / 2) * Math.sin(dLon / 2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
double d = R * c;
// Distance in km
return d;
}
private double deg2rad(double deg)
{
return deg * (Math.PI / 180);
}
This method is calculating exact distance for me.

You can calculate the distance between two point using the following function
double distanceBetweenTwoPoint(double srcLat, double srcLng, double desLat, double desLng) {
double earthRadius = 3958.75;
double dLat = Math.toRadians(desLat - srcLat);
double dLng = Math.toRadians(desLng - srcLng);
double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
+ Math.cos(Math.toRadians(srcLat))
* Math.cos(Math.toRadians(desLat)) * Math.sin(dLng / 2)
* Math.sin(dLng / 2);
double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
double dist = earthRadius * c;
double meterConversion = 1609;
return (int) (dist * meterConversion);
}
For the second Part: To use mock or sample data you can use "Fake GPS" app from the play store, which will generate mock location in your device.
Happy Coding

There are basically three ways to check the traveled distance -
By using GPS, check the coordinate between two points using distanceTo of Location class.
Using Accelerometer , you can check the movement of device using Accelerometer.
Using Step detector - this is recently updated by Android.
Hope this helps you to achieve your goal :)

For the first question . You have origin coordinates and the present user location coordinates so what you can do is google api v3 library provides a method that takes origin LatLng and destination LatLng and gives the distance . Add api v3 jar to your android build path.
For the second one goto google maps and give the location details it is accurate..

How can I calculate a current distance to polyline points on google maps v2 in android?

I have used tutorial from the link below to display Google map route in Android app. My question is how can I calculate distance to polyline points on map? Like when I use Google maps app and it tells when a street turn is getting close. I want to implement similar feature in my app. I am able to display the route polyline on the map and it updates itself while I drive along it but I want it to warn me 500 feet in advance of a coming turn. How can I do that?
Here is the link:
http://jigarlikes.wordpress.com/2013/04/26/driving-distance-and-travel-time-duration-between-two-locations-in-google-map-android-api-v2/

I use this method for Markers. Assuming you have Latitude and Longitude of the points that make up the Polyline this should do:
public class MapUtils {
public static float distBetween(LatLng pos1, LatLng pos2) {
return distBetween(pos1.latitude, pos1.longitude, pos2.latitude,
pos2.longitude);
}
/** distance in meters **/
public static float distBetween(double lat1, double lng1, double lat2, double 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 (float) (dist * meterConversion);
}
}
To determine wether the road is turning, I would look into euclidean angle between vectors (x being current location and y being a polyline point)
Simply take your current location and a LatLng from some distance ahead for this.
Calculation is based on: http://en.wikipedia.org/wiki/Euclidean_space#Angle
Location currentLocation; // obtained somewhere in your code
LatLng polylinePoint; // a point further ahead
double cLat = currentLocation.getLatitude();
double cLon = currentLocation.getLongitude();
double pLat = polylinePoint.latitude;
double pLon = polylinePoint.longitude;
double angle = Math.acos(
(cLat*pLat+cLon+pLon) / norm(cLat,cLon)*norm(pLat,cLon));
private double norm(double x, double y) {
return Math.sqrt(Math.pow(x, 2)*Math.pow(y, 2));
}
This is untested so might contain error.

i want to draw circle around my current location and find out other users which are come in range of this circle on my google map in android

in this my gps application i want to draw circle around my current location i did it ...but now i find out other users which are come in cirle range so i want popoup in my application screen so can anyboby help me...

you have just to compute the distance between each point and the center of the circle.
This can be done with something like this:
double d2r = (180 / Math.PI);
double distance = 0;
try{
double dlong = (endpoint.getLon() - startpoint.getLon()) * d2r;
double dlat = (endpoint.getLat() - startpoint.getLat()) * d2r;
double a =
Math.pow(Math.sin(dlat / 2.0), 2)
+ Math.cos(startpoint.getLat() * d2r)
* Math.cos(endpoint.getLat() * 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;
} catch(Exception e){
e.printStackTrace();
}
and then
if (distance < CIRCLE_RADIUS)
//The point is inside circle.

If you know the coordinates of the center of the circle and a friend you can call the static method Location.distanceBetween() to find the distance. As you must know the size of your circles radius its just a compare of the result of distanceBetween() and your radius.