text: // Main package function
  function latLonDistance(lat1, lon1, lat2, lon2, unit) {
  
      var radlat1 = Math.PI * lat1 / 180
      var radlat2 = Math.PI * lat2 / 180
      var radlon1 = Math.PI * lon1 / 180
      var radlon2 = Math.PI * lon2 / 180
      var theta = lon1 - lon2
      var radtheta = Math.PI * theta / 180
  
      var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
  
      dist = Math.acos(dist)
      dist = dist * 180 / Math.PI
      dist = dist * 60 * 1.1515
  
      if (unit == "K") { dist = dist * 1.609344 }
      if (unit == "N") { dist = dist * 0.8684 }
  
      var diss = '';
      if (dist < 1) {
  
          diss = (dist * 1000);
          diss = parseFloat(diss).toFixed(0) + ' meters';
      } else if (dist == 1) {
  
          diss = parseFloat(dist).toFixed(2) + ' km';
      } else {
  
          diss = parseFloat(dist).toFixed(2) + ' kms';
      }
  
      return diss;
  }
  
  module.exports = latLonDistance;