geo conversions / published by https://github.com/dacr/code-examples-manager #0b3d43a7-3e8a-4bca-a768-3a28bd84c3ea/bfdf1d813f21789d7804ebf9a7ff9370e2bfb0eb

algo-geo-conversions.sc

// summary : geo conversions
// keywords : scala, gps, dms, @testable
// publish : gist
// authors : David Crosson
// license : Apache NON-AI License Version 2.0 (https://raw.githubusercontent.com/non-ai-licenses/non-ai-licenses/main/NON-AI-APACHE2)
// id : 0b3d43a7-3e8a-4bca-a768-3a28bd84c3ea
// created-on : 2022-03-14T18:31:29+01:00
// managed-by : https://github.com/dacr/code-examples-manager
// run-with : scala-cli $file

// ---------------------
//> using scala  "3.3.0"
//> using dep "org.scalatest::scalatest:3.2.16"
//> using objectWrapper
// ---------------------

import org.scalatest.*
import flatspec.*
import matchers.*

import scala.util.{Failure, Success, Try}
import org.scalatest.TryValues.*

import java.util.Locale

/*
- Positive latitudes are north of the equator
- Negative latitudes are south of the equator
- Positive longitudes are east of the Prime Meridian
- Negative longitudes are west of the Prime Meridian.
- Latitude and longitude are usually expressed in that sequence, latitude before longitude.
- Reference NSEW is mandatory to give the right value sign (because -0° is not valid of course)
 */

val dmsRE = """[-+]?(\d+)[°]\s*(\d+)['′]\s*(\d+(?:[.,]\d+)?)(?:(?:")|(?:'')|(?:′′)|(?:″))""".r

def convert(d: Double, m: Double, s: Double): Double = d + m / 60d + s / 3600d

def degreesMinuteSecondsToDecimalDegrees(
  dms: String,
  ref: String
): Try[Double] = Try {
  val dd = dms.trim match {
    case dmsRE(d, m, s) => convert(d.toDouble, m.toDouble, s.replaceAll(",", ".").toDouble)
  }
  if ("NE".contains(ref.trim.toUpperCase.head)) dd else -dd
}

class GeoTest extends AnyFlatSpec with should.Matchers {
  "degrees minutes seconds" can "be decoded to decimal degrees" in {
    val toTest = List(
      ("N", "1° 00′ 0″", 1.0d),
      ("N", "0° 06′ 0″", 0.1d),
      ("N", "0° 00′ 36″", 0.01d),
      ("N", "0° 00′ 0.036″", 0.00001),
      ("E", "30° 15' 50\"", 30.263888889d),
      ("S", "3°58'24\"", -3.9733333333333336d),
      ("S", "-3°58'24\"", -3.9733333333333336d),
      ("N", "48° 18' 57,67\"", 48.31601944444444d)
    )
    toTest.foreach((ref, dms, dd) => {
      degreesMinuteSecondsToDecimalDegrees(dms, ref).success.value should equal(dd +- .000000001)
    })
  }
}

org.scalatest.tools.Runner.main(Array("-oDF", "-s", classOf[GeoTest].getName))