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/**
* @author Dachande663 [dachande663@gmail.com]
* @copyright Crown Copyright 2018
* @license Apache-2.0
*/
import Operation from "../Operation" ;
import OperationError from "../errors/OperationError" ;
/**
* HaversineDistance operation
*/
class HaversineDistance extends Operation {
/**
* HaversineDistance constructor
*/
constructor () {
super ();
this . name = "Haversine distance" ;
this . module = "Default" ;
this . description = "Returns the distance between two pairs of GPS latitude and longitude co-ordinates in metres.<br><br>e.g. <code>51.487263,-0.124323, 38.9517,-77.1467</code>" ;
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this . infoURL = "https://wikipedia.org/wiki/Haversine_formula" ;
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this . inputType = "string" ;
this . outputType = "number" ;
this . args = [];
}
/**
* @param {string} input
* @param {Object[]} args
* @returns {number}
*/
run ( input , args ) {
const values = input . match ( /^(-?\d+(\.\d+)?), ?(-?\d+(\.\d+)?), ?(-?\d+(\.\d+)?), ?(-?\d+(\.\d+)?)$/ );
if ( ! values ) {
throw new OperationError ( "Input must in the format lat1, lng1, lat2, lng2" );
}
const lat1 = parseFloat ( values [ 1 ]);
const lng1 = parseFloat ( values [ 3 ]);
const lat2 = parseFloat ( values [ 6 ]);
const lng2 = parseFloat ( values [ 8 ]);
const TO_RAD = Math . PI / 180 ;
const dLat = ( lat2 - lat1 ) * TO_RAD ;
const dLng = ( lng2 - lng1 ) * TO_RAD ;
const a = Math . sin ( dLat / 2 ) * Math . sin ( dLat / 2 ) + Math . cos ( lat1 * TO_RAD ) * Math . cos ( lat2 * TO_RAD ) * Math . sin ( dLng / 2 ) * Math . sin ( dLng / 2 );
const metres = 6371000 * 2 * Math . atan2 ( Math . sqrt ( a ), Math . sqrt ( 1 - a ));
return metres ;
}
}
export default HaversineDistance ;