CODEWITHSUNDEEP
iphoneobjective-ciosgoogle-mapsgoogle-maps-api-3
1110
1110

Reputation: 6829

How to check if current coordinates are within a radius of other coordinates

I have latitude and longitude of a fixed location. I want to check if another location (latitude and longitude) is close enough (50-100 meters) to the fixed location. I use iPhone to get current location.

Upvotes: 6

Views: 12707

Answers (7)

Lance Samaria
Lance Samaria

Reputation: 19572

Here's how to do it in Swift using CoreLocation. You just compare 2 different locations using the .distance(from: ) method on a location that is of type CLLocation. Make sure both locations are of type CLLocation

import CoreLocation

let someOtherLocation: CLLocation = CLLocation(latitude: someOtherLat,
                                               longitude: someOtherLon)

guard let usersCurrentLocation: CLLocation = locationManager.location else { return }

                                                       // **the distance(from: ) is right here **
let distanceInMeters: CLLocationDistance = usersCurrentLocation.distance(from: someOtherLocation)

if distanceInMeters < 100 {

    // this user is pretty much in the same area as the otherLocation
} else {

   // this user is at least over 100 meters outside the otherLocation
}

this isn't necessary but maybe you need to save the lats and lons for later for another comparison. I know I needed them

let usersCurrentLat: CLLocationDegrees = currentLocation.coordinate.latitude // not neccessary but this is how you get the lat
let usersCurrentLon: CLLocationDegrees = currentLocation.coordinate.longitude // not neccessary but this is how you get the lon

let someOtherLocationLat: CLLocationDegrees = someOtherLocationLocation.coordinate.latitude // not neccessary but this is how you get the lat
let someOtherLocationLon: CLLocationDegrees = someOtherLocationtLocation.coordinate.longitude // not neccessary but this is how you get the lon


let usersLocation: CLLocation = CLLocation(latitude: usersCurrentLat,
                                           longitude: usersCurrentLon)

let otherLocation: CLLocation = CLLocation(latitude: someOtherLocationLat,
                                           longitude: someOtherLocationLon)

Upvotes: 3

Deepukjayan
Deepukjayan

Reputation: 3695

distanceFromCurrentLocation = [userLocation distanceFromLocation:destinationlocation]/convertToKiloMeter;
if(distanceFromCurrentLocation < 100 && distanceFromLocation > .500)
{
    NSLog(@"Yeah, this place is inside my circle");
}
else
{
    NSLog(@"Oops!! its too far");
}

This finds the air distance, or we can say, straight line distance only.
Hope you are not looking for road distance.

Upvotes: 7

Pietro Sette
Pietro Sette

Reputation: 62

func distance(from location: CLLocation) -> CLLocationDistance

Documentation

Upvotes: 0

EmptyStack
EmptyStack

Reputation: 51374

The method – distanceFromLocation: of CLLocation is exactly what you need.

Upvotes: 14

Rodrigo Pinto
Rodrigo Pinto

Reputation: 2414

Adding to Deepukjayan answer, use CLLocation to define a reference before using his answer:

CLLocation *montreal = [[CLLocation alloc] initWithLatitude:45.521731 longitude:-73.628679];

Upvotes: 1

Shubhank
Shubhank

Reputation: 21805

Although i Upvoted Empty Stack answer.. If you need more help here is the code..

Be the CLLocationManagerDelegate and then in your implementation class. 

 - (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{


            int distance = [newLocation distanceFromLocation:oldLocation];
            if(distance >50 && distance <100)
            {

            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Distance"
                                                            message:[NSString stringWithFormat:@"%i meters",distance]
                                                           delegate:nil
                                                  cancelButtonTitle:@"OK"
                                                  otherButtonTitles:nil];
            [alert show];
            [alert release];
            }
        }
    }

Upvotes: 1

Eugene
Eugene

Reputation: 10045

CLLocation *location;// = init...;
double distance = [location distanceFromLocation:otherLoc]; //in meters

Upvotes: 1

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