Map Region Encompassing Coords w/ Padding

regionForCoords.m

- (MKCoordinateRegion)regionForCoords:(NSArray *)coords withPaddingFactor:(CGFloat)paddingFactor {

    CLLocationDegrees minLat = 90.0;
    CLLocationDegrees maxLat = -90.0;
    CLLocationDegrees minLon = 180.0;
    CLLocationDegrees maxLon = -180.0;

    for (NSValue *val in coords) {
        CLLocationCoordinate2D coord = [val MKCoordinateValue];
        if (coord.latitude < minLat) {
            minLat = coord.latitude;
        }
        if (coord.longitude < minLon) {
            minLon = coord.longitude;
        }
        if (coord.latitude > maxLat) {
            maxLat = coord.latitude;
        }
        if (coord.longitude > maxLon) {
            maxLon = coord.longitude;
        }
    }

    CLLocationDegrees latDelta = (maxLat - minLat);
    CLLocationDegrees latPadding = latDelta * paddingFactor;
    latDelta += latPadding;
    CLLocationDegrees lonDelta = (maxLon - minLon);
    CLLocationDegrees lonPadding = lonDelta * paddingFactor;
    lonDelta += lonPadding;

    CLLocationDegrees latitudeOffset = fabs(latDelta / 2.0);
    CLLocationDegrees longitudeOffset = fabs(lonDelta / 2.0);

    minLat -= latitudeOffset;
    maxLat += latitudeOffset;
    minLon -= longitudeOffset;
    maxLon += longitudeOffset;

    MKCoordinateSpan span = MKCoordinateSpanMake(latDelta, lonDelta);

    CLLocationDegrees middleLatitude = (maxLat + minLat) / 2;
    CLLocationDegrees middleLongitude = (maxLon + minLon) / 2;
    CLLocationCoordinate2D centerCoordinate = CLLocationCoordinate2DMake(middleLatitude, middleLongitude);

    return MKCoordinateRegionMake(centerCoordinate, span);
}