/usr/share/javascript/proj4/lib/common/iqsfnz.js is in libjs-proj4 2.3.17+ds-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | var HALF_PI = Math.PI/2;
module.exports = function(eccent, q) {
var temp = 1 - (1 - eccent * eccent) / (2 * eccent) * Math.log((1 - eccent) / (1 + eccent));
if (Math.abs(Math.abs(q) - temp) < 1.0E-6) {
if (q < 0) {
return (-1 * HALF_PI);
}
else {
return HALF_PI;
}
}
//var phi = 0.5* q/(1-eccent*eccent);
var phi = Math.asin(0.5 * q);
var dphi;
var sin_phi;
var cos_phi;
var con;
for (var i = 0; i < 30; i++) {
sin_phi = Math.sin(phi);
cos_phi = Math.cos(phi);
con = eccent * sin_phi;
dphi = Math.pow(1 - con * con, 2) / (2 * cos_phi) * (q / (1 - eccent * eccent) - sin_phi / (1 - con * con) + 0.5 / eccent * Math.log((1 - con) / (1 + con)));
phi += dphi;
if (Math.abs(dphi) <= 0.0000000001) {
return phi;
}
}
//console.log("IQSFN-CONV:Latitude failed to converge after 30 iterations");
return NaN;
};
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