Swift Convert decimal coordinate into degrees, minutes, seconds, direction - swift

Question

How can I covert this to swift? My best guess is that all the int get changed to a var. Removing all the # that lead ". Also if any can point me to a good source to learn how things convert that would great.
- (NSString*)coordinateString {
int latSeconds = (int)(self.latitude * 3600);
int latDegrees = latSeconds / 3600;
latSeconds = ABS(latSeconds % 3600);
int latMinutes = latSeconds / 60;
latSeconds %= 60;
int longSeconds = (int)(self.longitude * 3600);
int longDegrees = longSeconds / 3600;
longSeconds = ABS(longSeconds % 3600);
int longMinutes = longSeconds / 60;
longSeconds %= 60;
NSString* result = [NSString stringWithFormat:#"%d°%d'%d\"%# %d°%d'%d\"%#",
ABS(latDegrees),
latMinutes,
latSeconds,
latDegrees >= 0 ? #"N" : #"S",
ABS(longDegrees),
longMinutes,
longSeconds,
longDegrees >= 0 ? #"E" : #"W"];
return result;
}
My attempt to convert it but Xcode proves me wrong. Reposted the fix suggest with the ABS. Does it look correct now?
func coordinateString {
var latSeconds = (Int8)(self.latitude * 3600);
var latDegrees = latSeconds / 3600;
latSeconds = abs(latSeconds % 3600);
var latMinutes = latSeconds / 60;
latSeconds %= 60;
var longSeconds = (Int8)(self.longitude * 3600);
var longDegrees = longSeconds / 3600;
longSeconds = abs(longSeconds % 3600);
var longMinutes = longSeconds / 60;
longSeconds %= 60;
var result = (String(format: "%d°%d'%d\"%# %d°%d'%d\"%#"),
abs(latDegrees),
latMinutes,
latSeconds,
latDegrees >= 0 ? "N" : "S",
abs(longDegrees),
longMinutes,
longSeconds,
longDegrees >= 0 ? "E" : "W",
return result;
}

Answer 1

Xcode 12 • Swift 5 or later
extension BinaryFloatingPoint {
var dms: (degrees: Int, minutes: Int, seconds: Int) {
var seconds = Int(self * 3600)
let degrees = seconds / 3600
seconds = abs(seconds % 3600)
return (degrees, seconds / 60, seconds % 60)
}
}
extension CLLocation {
var dms: String { latitude + " " + longitude }
var latitude: String {
let (degrees, minutes, seconds) = coordinate.latitude.dms
return String(format: "%d°%d'%d\"%#", abs(degrees), minutes, seconds, degrees >= 0 ? "N" : "S")
}
var longitude: String {
let (degrees, minutes, seconds) = coordinate.longitude.dms
return String(format: "%d°%d'%d\"%#", abs(degrees), minutes, seconds, degrees >= 0 ? "E" : "W")
}
}
let latitude = -22.9133950
let longitude = -43.2007100
let location = CLLocation(latitude: latitude, longitude: longitude)
location.latitude // "22°54'48"S"
location.longitude // "43°12'2"W"
location.dms // "22°54'48"S 43°12'2"W"

Answer 2

I have just edited Leo Dabus answer to get those String as separate values. In case it is helpful for others:
Swift 3 and Swift 4
func getLocationDegreesFrom(latitude: Double) -> String {
var latSeconds = Int(latitude * 3600)
let latDegrees = latSeconds / 3600
latSeconds = abs(latSeconds % 3600)
let latMinutes = latSeconds / 60
latSeconds %= 60
return String(
format: "%d°%d'%d\"%#",
abs(latDegrees),
latMinutes,
latSeconds,
latDegrees >= 0 ? "N" : "S"
)
}
func getLocationDegreesFrom(longitude: Double) -> String {
var longSeconds = Int(longitude * 3600)
let longDegrees = longSeconds / 3600
longSeconds = abs(longSeconds % 3600)
let longMinutes = longSeconds / 60
longSeconds %= 60
return String(
format: "%d°%d'%d\"%#",
abs(longDegrees),
longMinutes,
longSeconds,
longDegrees >= 0 ? "E" : "W"
)
}

Answer 3

I took the code of Leo Dabus and fixed a bug related with the detection of the cardinal directions when the values of the latitude or longitude are less than zero, I mean when we are at southern hemisphere or west of the prime meridian.
We can't represent a negative zero with Swift, so we lose the negative sign at the following expression:
let latDegrees = latSeconds / 3600
this bug also makes the expresion:
latDegrees >= 0 ? "N" : "S"
always return N (North) and never S (South).
Here is my version of the code (Swift 5 and Xcode 10):
func coordinate() -> (latitude: String, longitude: String) {
// This function converts from DD (decimal degrees) to DMS (degrees, minutes and seconds)
// Calculating the degrees, minutes and seconds for the given latitude value (DD)
var latitudeSeconds = latitude * 3600
let latitudeDegrees = latitudeSeconds / 3600
latitudeSeconds = latitudeSeconds.truncatingRemainder(dividingBy: 3600)
let latitudeMinutes = latitudeSeconds / 60
latitudeSeconds = latitudeSeconds.truncatingRemainder(dividingBy: 60)
// Calculating the degrees, minutes and seconds for the given longitude value (DD)
var longitudeSeconds = longitude * 3600
let longitudeDegrees = longitudeSeconds / 3600
longitudeSeconds = longitudeSeconds.truncatingRemainder(dividingBy: 3600)
let longitudeMinutes = longitudeSeconds / 60
longitudeSeconds = longitudeSeconds.truncatingRemainder(dividingBy: 60)
// Analyzing if it's North or South. (Latitude)
let latitudeCardinalDirection = latitudeDegrees >= 0 ? "N" : "S"
// Analyzing if it's East or West. (Longitude)
let longitudeCardinalDirection = longitudeDegrees >= 0 ? "E" : "W"
// Final strings with format <degrees>°<minutes>'<seconds>"<cardinal direction>
let latitudeDescription = String(format:"%.2f°%.2f'%.2f\"%#",
abs(latitudeDegrees), abs(latitudeMinutes),
abs(latitudeSeconds), latitudeCardinalDirection)
let longitudeDescription = String(format:"%.2f°%.2f'%.2f\"%#",
abs(longitudeDegrees), abs(longitudeMinutes),
abs(longitudeSeconds), longitudeCardinalDirection)
return (latitudeDescription, longitudeDescription)
} // coordinate
I also chose to work with Double in order to handle the precision, for example, I prefer to show two decimal places.
The screen output of this code would be something like:
0.17°10.34'20.53"S 78.48°28.59'35.52"W

Answer 4

Based on David Seek and Josué V. Herrera code
func latlon2DMS(latitude: Double) -> String {
var latitudeSeconds = latitude * 3600
let latitudeDegrees = latitudeSeconds / 3600
latitudeSeconds = latitudeSeconds.truncatingRemainder(dividingBy: 3600)
let latitudeMinutes = latitudeSeconds / 60
latitudeSeconds = latitudeSeconds.truncatingRemainder(dividingBy: 60)
let latitudeCardinalDirection = latitudeDegrees >= 0 ? "N" : "S"
let latitudeDescription = String(format: "%.2f° %.2f' %.2f\" %#",
abs(latitudeDegrees), abs(latitudeMinutes),
abs(latitudeSeconds), latitudeCardinalDirection)
return latitudeDescription
}
func latlon2DMS(longitude: Double) -> String {
var longitudeSeconds = longitude * 3600
let longitudeDegrees = longitudeSeconds / 3600
longitudeSeconds = longitudeSeconds.truncatingRemainder(dividingBy: 3600)
let longitudeMinutes = longitudeSeconds / 60
longitudeSeconds = longitudeSeconds.truncatingRemainder(dividingBy: 60)
let longitudeCardinalDirection = longitudeDegrees >= 0 ? "E" : "W"
let longitudeDescription = String(format: "%.2f° %.2f' %.2f\" %#",
abs(longitudeDegrees), abs(longitudeMinutes),
abs(longitudeSeconds), longitudeCardinalDirection)
return longitudeDescription
}
Call to it with
print(latlon2DMS(latitude: coordLat))
print(latlon2DMS(longitude: coordLong))
latitude.text = latlon2DMS(latitude: coordLat)
longitude.text = latlon2DMS(longitude: coordLong)

Answer 5

I slightly modified Josue V.'s code to work in a timer that updates the location frequently
if( CLLocationManager.authorizationStatus() == .authorizedWhenInUse ||
CLLocationManager.authorizationStatus() == .authorizedAlways){
let currentLocation = locationManager.location
var latitudeSeconds = currentLocation!.coordinate.latitude * 3600
let latitudeDegrees = latitudeSeconds / 3600
latitudeSeconds = latitudeSeconds.truncatingRemainder(dividingBy: 3600)
let latitudeMinutes = latitudeSeconds / 60
latitudeSeconds = latitudeSeconds.truncatingRemainder(dividingBy: 60)
var longitudeSeconds = currentLocation!.coordinate.longitude * 3600
let longitudeDegrees = longitudeSeconds / 3600
longitudeSeconds = longitudeSeconds.truncatingRemainder(dividingBy: 3600)
let longitudeMinutes = longitudeSeconds / 60
longitudeSeconds = longitudeSeconds.truncatingRemainder(dividingBy: 60)
let latitudeCardinalDirection = latitudeDegrees >= 0 ? "N" : "S"
let longitudeCardinalDirection = longitudeDegrees >= 0 ? "E" : "W"
let latitudeDescription = String(format:"%.2f°%.2f'%.2f\"%#",
abs(latitudeDegrees), abs(latitudeMinutes),
abs(latitudeSeconds), latitudeCardinalDirection)
let longitudeDescription = String(format:"%.2f°%.2f'%.2f\"%#",
abs(longitudeDegrees), abs(longitudeMinutes),
abs(longitudeSeconds), longitudeCardinalDirection)
cell5.text = latitudeDescription + " " + longitudeDescription
}
}
and the timer
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(coordinate), userInfo: nil, repeats: true)