distanceFromLocation seems not working

Question

In an app I need to calculate the distance between two point. I'm doing it like this.

- (void)locationManager:(CLLocationManager *)manager
    didUpdateToLocation:(CLLocation *)newLocation
           fromLocation:(CLLocation *)oldLocation{
    NSLog(@"updating");
     //Getting my concerts
    arrConcerten = [matches mutableCopy];

       for (Event *concert in arrConcerten) {
            CLLocation *restaurnatLoc = [[CLLocation alloc] initWithLatitude:[concert.eve_latitude floatValue] longitude:[concert.eve_longitude floatValue]];

            CLLocationDistance meters = [restaurnatLoc distanceFromLocation:newLocation];
            NSLog(@"meters are %f",meters);
            if(meters > 5000){
                [locationManager2 stopUpdatingLocation];
                NSString *message2 = [NSString stringWithFormat:@"Long = %f and lat= %f and Concert Lat = %f and long = %f",newLocation.coordinate.longitude,newLocation.coordinate.latitude,[concert.eve_latitude floatValue],[concert.eve_longitude floatValue]];
                NSLog(@"%@",message2);
            }else{

                NSLog(@"too far away");
            }

        }
    }

This is what my log says.

2013-10-17 15:57:23.518 Domino[7468:907] meters are 7973.753294
2013-10-17 15:57:23.520 Domino[7468:907] Long = 5.621456 and lat= 51.097340 and Concert Lat = 51.038139 and long = 5.557330
2013-10-17 15:57:23.896 Domino[7468:907] meters are 27850.874245
2013-10-17 15:57:23.899 Domino[7468:907] Long = 5.621456 and lat= 51.097340 and Concert Lat = 50.860332 and long = 5.493722

Like you can see, the locations are near each other. but it still says that we are too far away. Can somebody help me ?

Answer 1

Why are you using this:

if it s over 5000 meter: do something, else too far away? I don't understand the logic. If its too far away it's over 5000 meter. So I think:

  - (void)locationManager:(CLLocationManager *)manager
        didUpdateToLocation:(CLLocation *)newLocation
               fromLocation:(CLLocation *)oldLocation{
        NSLog(@"updating");
         //Getting my concerts
        arrConcerten = [matches mutableCopy];

       for (Event *concert in arrConcerten) {
            CLLocation *restaurnatLoc = [[CLLocation alloc] initWithLatitude:[concert.eve_latitude floatValue] longitude:[concert.eve_longitude floatValue]];

            CLLocationDistance meters = [restaurnatLoc distanceFromLocation:newLocation];
            NSLog(@"meters are %f",meters);
            if(meters <= 5000){
                [locationManager2 stopUpdatingLocation];
                NSString *message2 = [NSString stringWithFormat:@"Long = %f and lat= %f and Concert Lat = %f and long = %f",newLocation.coordinate.longitude,newLocation.coordinate.latitude,[concert.eve_latitude floatValue],[concert.eve_longitude floatValue]];
                NSLog(@"%@",message2);
            }else{

                NSLog(@"too far away");
            }

        }
    }

or of corse:

if(meters > 5000){

                    NSLog(@"it's far enough");
 }else{

                    NSLog(@"too close");
 }

And there is a really important thing:

This method measures the distance between the two locations by tracing a line between them that follows the curvature of the Earth. The resulting arc is a smooth curve and does not take into account specific altitude changes between the two locations. from apple documentation

distanceFromLocation measure the distance "in the air", not a turn by turn measure.

Answer 2

Here is the Solution-

-(NSString *)getDistance:(NSDictionary *)dicVal{
    CLLocation *pinLocation = [[CLLocation alloc] initWithLatitude:[[dicVal valueForKey:@"latitude"] doubleValue] longitude:[[dicVal valueForKey:@"longitude"] doubleValue]];

    CLLocation *userLocation = [[CLLocation alloc] initWithLatitude:appDelegate.userLocation.latitude longitude:appDelegate.userLocation.longitude];

    CLLocationDistance distance = [pinLocation distanceFromLocation:userLocation];
    NSString *dist=[NSString stringWithFormat:@"%4.0f %@", distance/1000,NSLocalizedString(@"KM", nil)];
    return dist;
}

Answer 3

Yes its just issue of allocation you have to allocate every time cllocation manager like as below:

LocationManager = [[[CLLocationManager alloc] init] autorelease];
LocationManager.delegate = self;
LocationManager.desiredAccuracy = kCLLocationAccuracyBest;
LocationManager.distanceFilter = kCLDistanceFilterNone;
[LocationManager startUpdatingLocation];
CLLocation *location = [LocationManager location];
CLLocationCoordinate2D coordinate1 = [location coordinate];


CLLocation *currentLoc = [[CLLocation alloc] initWithLatitude:coordinate1.latitude longitude:coordinate1.longitude];
CLLocation *restaurnatLoc = [[CLLocation alloc] initWithLatitude:l@"Your latitude not current" longitude:@"Your longitude not current'];
CLLocationDistance meters = [restaurnatLoc distanceFromLocation:currentLoc];    


if (meters > 1000)
{
    Distancelbl.text=[NSString stringWithFormat: @"You are Away %.2f Km",meters];
}
else{
    Distancelbl.text=[NSString stringWithFormat: @"You are Away %.2f Mtr",meters];
}

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