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<!-- :::                                                                         ::: -->
<!-- :::  This routine calculates the distance between two points (given the     ::: -->
<!-- :::  latitude/longitude of those points). It is being used to calculate     ::: -->
<!-- :::  the distance between two locations using GeoDataSource (TM) products   ::: -->
<!-- :::                                                                         ::: -->
<!-- :::  Definitions:                                                           ::: -->
<!-- :::    South latitudes are negative, east longitudes are positive           ::: -->
<!-- :::                                                                         ::: -->
<!-- :::  Passed to function:                                                    ::: -->
<!-- :::    lat1, lon1 = Latitude and Longitude of point 1 (in decimal degrees)  ::: -->
<!-- :::    lat2, lon2 = Latitude and Longitude of point 2 (in decimal degrees)  ::: -->
<!-- :::                                                                         ::: -->
<!-- :::  Worldwide cities and other features databases with latitude longitude  ::: -->
<!-- :::  are available at https://www.geodatasource.com                         ::: -->
<!-- :::                                                                         ::: -->
<!-- :::  For enquiries, please contact sales@geodatasource.com                  ::: -->
<!-- :::                                                                         ::: -->
<!-- :::  Official Web site: https://www.geodatasource.com                       ::: -->
<!-- :::                                                                         ::: -->
<!-- :::             GeoDataSource.com (C) All Rights Reserved 2022              ::: -->
<!-- :::                                                                         ::: -->
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<cfscript>
  function distance(lat1, lon1, lat2, lon2, unit) {
    if ((lat1 == lat2) && (lon1 == lon2)) {
      return 0;
    }
    else {
      theta = lon1 - lon2;
      dist = sin(deg2rad(lat1)) * sin(deg2rad(lat2)) + cos(deg2rad(lat1)) * cos(deg2rad(lat2)) * cos(deg2rad(theta));
      dist = acos(dist);
      dist = rad2deg(dist);
      distance = dist * 60 * 1.1515;
      if (unit == "K") {
        distance = distance * 1.609344;
    }
      elseif (unit == "N") {
          distance = distance * 0.8684;
      }
      return distance;
    }
  }
  
  function deg2rad(deg) {
    return (deg * pi() / 180);
  }
  
  function rad2deg(rad) {
    return (rad * 180 / pi());
  }
  
  WriteOutput(distance(32.9697, -96.80322, 29.46786, -98.53506, "K") & " Kilometers");
</cfscript>