haversine formula - Kotlin Multiplatform

haversine.kt

import kotlin.math.asin
import kotlin.math.cos
import kotlin.math.sqrt
import kotlin.math.PI

fun toRadians(deg: Double): Double = deg / 180.0 * PI

data class Location(
    val lat: Double,
    val lon: Double,
) {

    companion object {
        const val EARTH_RADIUS_KM: Double = 6371.0
    }

    /**
     * Calculates the Haversine distance between this location and the destination location.
     * For more information, see [Haversine formula](https://en.wikipedia.org/wiki/Haversine_formula#:~:text=The%20haversine%20formula%20determines%20the,and%20angles%20of%20spherical%20triangles).
     */
    fun haversine(destination: Location): Double {
        val dGama = toRadians(destination.lat - this.lat)
        val dLambda = toRadians(destination.lon - this.lon)
        val originLat = toRadians(this.lat)
        val destinationLat = toRadians(destination.lat)
        val a = 1 - cos(dGama) + cos(originLat) * cos(destinationLat) * (1 - cos(dLambda))
        return EARTH_RADIUS_KM * 2 * asin(sqrt(a/2))
    }
}


fun main(){
    val nebraska = Location(41.507483, -99.436554)
    val distance = nebraska.haversine(nebraska)
    println("distance to same location: $distance")
    
    val kansas = Location(38.504048, -98.315949)
    val result = nebraska.haversine(kansas)
    println("distance on map 347.3 result: $result")
}