CODEWITHSUNDEEP
iosmapscoordinates
Nicke
Nicke

Reputation: 113

iOS comparing geographical locations

I wonder how I calculate the distance between the iPhone user position and a given coordinates stored in a plist for example?

Upvotes: 1

Views: 1448

Answers (2)

Martin Adoue
Martin Adoue

Reputation: 66

This is the general formula to calculate the instance between to points, in kilometers. 

acos(sin(lat1rad) * sin(lat2rad) + cos(lat1rad) * cos(lat2rad) * cos(lon2rad - lon1rad))) * 6378.1

6378.1 is the approx. radius of the Earth in kilometers. Make sure you express de values in radians and not in degrees. Just in case, the easiest way to convert degrees to radians is:

radians = (degrees * 0.01745329) // degrees * pi over 180

EDIT: fixed the formula to convert between degrees and radians. Thank you Ozzah!

Upvotes: 1

Deepak Danduprolu
Deepak Danduprolu

Reputation: 44633

You can use the CLLocation method distanceFromLocation: to calculate between two CLLocation objects. You can use CLLocationManager to get user's current location and you can create a CLLocation instance for the coordinates using initWithLatitude:longitude: initializer.

distanceFromLocation: returns the distance in meters.

Upvotes: 6

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