As title said, I have current location, and want to know the bearing in degree from my current location to other location. I have read this post , is the value return by location.getBearing() my answer?
Let say it simply: from the picture, I expect the value of 45 degree.
I was having trouble doing this and managed to figure it out converting the C? approach to working out the bearing degree.
I worked this out using 4 coordinate points
Start Latitude
Start Longitude
End Latitude
End Longitude
Here's the code:
protected double bearing(double startLat, double startLng, double endLat, double endLng){
double latitude1 = Math.toRadians(startLat);
double latitude2 = Math.toRadians(endLat);
double longDiff= Math.toRadians(endLng - startLng);
double y= Math.sin(longDiff)*Math.cos(latitude2);
double x=Math.cos(latitude1)*Math.sin(latitude2)-Math.sin(latitude1)*Math.cos(latitude2)*Math.cos(longDiff);
return (Math.toDegrees(Math.atan2(y, x))+360)%360;
}
Just change the variable names were needed.
Output bearing to a TextView
Hope it helped!
Location have method bearingTo: float bearingTo(Location dest)
Location from = new Location(LocationManager.GPS_PROVIDER);
Location to = new Location(LocationManager.GPS_PROVIDER);
from.setLatitude(0);
from.setLongitude(0);
to.setLongitude(10);
to.setLatitude(10);
float bearingTo = from.bearingTo(to);
Here is the code for calculating bearing angle between two points(startPoint, endPoint):
public float CalculateBearingAngle(double startLatitude,double startLongitude, double endLatitude, double endLongitude){
double Phi1 = Math.toRadians(startLatitude);
double Phi2 = Math.toRadians(endLatitude);
double DeltaLambda = Math.toRadians(endLongitude - startLongitude);
double Theta = atan2((sin(DeltaLambda)*cos(Phi2)) , (cos(Phi1)*sin(Phi2) - sin(Phi1)*cos(Phi2)*cos(DeltaLambda)));
return (float)Math.toDegrees(Theta);
}
Call for function:
float angle = CalculateBearingAngle(startLatitude, startLongitude, endLatitude, endLongitude);
I found best method for calculating "Bearing between two point " from this answer and convert it to java from python. And this method work like charm for me!
here is the code:
public static double getBearing(double startLat, double startLng, double endLat, double endLng) {
double latitude1 = Math.toRadians(startLat);
double longitude1 = Math.toRadians(-startLng);
double latitude2 = Math.toRadians(endLat);
double longitude2 = Math.toRadians(-endLng);
double dLong = longitude2 - longitude1;
double dPhi = Math.log(Math.tan(latitude2 / 2.0 + Math.PI / 4.0) / Math.tan(latitude1 / 2.0 + Math.PI / 4.0));
if (abs(dLong) > Math.PI)
if (dLong > 0.0)
dLong = -(2.0 * Math.PI - dLong);
else
dLong = (2.0 * Math.PI + dLong);
return (Math.toDegrees(Math.atan2(dLong, dPhi)) + 360.0) % 360.0;
}
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