function deg2rad ( deg ) { return deg * ( Math . PI / 180 ) ; } export function getDistanceFromLatLonInKm ( lat1 , lon1 , lat2 , lon2 ) { const R = 6371 ; const dLat = deg2rad ( lat2 - lat1 ) ; const dLon = deg2rad ( lon2 - lon1 ) ; const a = Math . sin ( dLat / 2 ) * Math . sin ( dLat / 2 ) + Math . cos ( deg2rad ( lat1 ) ) * Math . cos ( deg2rad ( lat2 ) ) * Math . sin ( dLon / 2 ) * Math . sin ( dLon / 2 ) ; const c = 2 * Math . atan2 ( Math . sqrt ( a ) , Math . sqrt ( 1 - a ) ) ; const d = R * c ; return d . toFixed ( 2 ) ; }