let initialLocation = CLLocation(latitude: 21.282778, longitude: -157.829444)
let regionRadius: CLLocationDistance = 1000

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    centerMapOnLocation(location: initialLocation)
}

func centerMapOnLocation(location: CLLocation) {
    let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate, regionRadius, regionRadius)
    mapView.setRegion(coordinateRegion, animated: true)
}