mirror of
https://github.com/proj4js/proj4js.git
synced 2026-01-18 16:13:22 +00:00
16 lines
461 B
JavaScript
16 lines
461 B
JavaScript
var HALF_PI = Math.PI/2;
|
|
module.exports = function(eccent, ts) {
|
|
var eccnth = 0.5 * eccent;
|
|
var con, dphi;
|
|
var phi = HALF_PI - 2 * Math.atan(ts);
|
|
for (var i = 0; i <= 15; i++) {
|
|
con = eccent * Math.sin(phi);
|
|
dphi = HALF_PI - 2 * Math.atan(ts * (Math.pow(((1 - con) / (1 + con)), eccnth))) - phi;
|
|
phi += dphi;
|
|
if (Math.abs(dphi) <= 0.0000000001) {
|
|
return phi;
|
|
}
|
|
}
|
|
//console.log("phi2z has NoConvergence");
|
|
return -9999;
|
|
}; |