tsgeo
Version:
TsGeo provides abstractions to geographical coordinates (including support for different ellipsoids) and allows you to calculate geographical distances between coordinates with high precision.
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JavaScript
;
/**
* Implementation of distance calculation with Vincenty Method
*
* @author clemdesign <contact@clemdesign.fr>
* @license https://opensource.org/licenses/MIT
* @link
*/
Object.defineProperty(exports, "__esModule", { value: true });
const MathMore_1 = require("../Functions/MathMore");
class Vincenty {
/**
* @param {Coordinate} point1
* @param {Coordinate} point2
*
* @return number|null
*/
getDistance(point1, point2) {
if (point1.getEllipsoid().getName() !== point2.getEllipsoid().getName()) {
return 0;
}
let lat1 = MathMore_1.MathMore.deg2rad(point1.getLat());
let lat2 = MathMore_1.MathMore.deg2rad(point2.getLat());
let lng1 = MathMore_1.MathMore.deg2rad(point1.getLng());
let lng2 = MathMore_1.MathMore.deg2rad(point2.getLng());
let a = point1.getEllipsoid().getA();
let b = point1.getEllipsoid().getB();
let f = (1 / point1.getEllipsoid().getF());
let L = lng2 - lng1;
let U1 = Math.atan((1 - f) * Math.tan(lat1));
let U2 = Math.atan((1 - f) * Math.tan(lat2));
let iterationLimit = 100;
let lambda = L;
let sinU1 = Math.sin(U1);
let sinU2 = Math.sin(U2);
let cosU1 = Math.cos(U1);
let cosU2 = Math.cos(U2);
let lambdaP;
let cosSqAlpha;
let sinSigma;
let cos2SigmaM;
let cosSigma;
let sigma;
do {
let sinLambda = Math.sin(lambda);
let cosLambda = Math.cos(lambda);
sinSigma = Math.sqrt((cosU2 * sinLambda) * (cosU2 * sinLambda) +
(cosU1 * sinU2 - sinU1 * cosU2 * cosLambda) * (cosU1 * sinU2 - sinU1 * cosU2 * cosLambda));
if (sinSigma == 0) {
return 0.0;
}
cosSigma = sinU1 * sinU2 + cosU1 * cosU2 * cosLambda;
sigma = Math.atan2(sinSigma, cosSigma);
let sinAlpha = cosU1 * cosU2 * sinLambda / sinSigma;
cosSqAlpha = 1 - sinAlpha * sinAlpha;
cos2SigmaM = 0;
if (cosSqAlpha != 0) {
cos2SigmaM = cosSigma - 2 * sinU1 * sinU2 / cosSqAlpha;
}
let C = f / 16 * cosSqAlpha * (4 + f * (4 - 3 * cosSqAlpha));
lambdaP = lambda;
lambda = L + (1 - C) * f * sinAlpha * (sigma + C * sinSigma * (cos2SigmaM + C * cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM)));
} while (Math.abs(lambda - lambdaP) > 1e-12 && --iterationLimit > 0);
if (iterationLimit === 0) {
return 0;
}
let uSq = cosSqAlpha * (a * a - b * b) / (b * b);
let A = 1 + uSq / 16384 * (4096 + uSq * (-768 + uSq * (320 - 175 * uSq)));
let B = uSq / 1024 * (256 + uSq * (-128 + uSq * (74 - 47 * uSq)));
let deltaSigma = B * sinSigma * (cos2SigmaM + B / 4 * (cosSigma * (-1 + 2 * cos2SigmaM * cos2SigmaM) - B / 6 * cos2SigmaM * (-3 + 4 * sinSigma * sinSigma) * (-3 + 4 * cos2SigmaM * cos2SigmaM)));
let s = b * A * (sigma - deltaSigma);
return MathMore_1.MathMore.round10(s, -3);
}
}
exports.Vincenty = Vincenty;