var gauss = require('./gauss');
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var adjust_lon = require('../common/adjust_lon');
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exports.init = function() {
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gauss.init.apply(this);
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if (!this.rc) {
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return;
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}
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this.sinc0 = Math.sin(this.phic0);
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this.cosc0 = Math.cos(this.phic0);
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this.R2 = 2 * this.rc;
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if (!this.title) {
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this.title = "Oblique Stereographic Alternative";
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}
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};
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exports.forward = function(p) {
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var sinc, cosc, cosl, k;
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p.x = adjust_lon(p.x - this.long0);
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gauss.forward.apply(this, [p]);
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sinc = Math.sin(p.y);
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cosc = Math.cos(p.y);
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cosl = Math.cos(p.x);
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k = this.k0 * this.R2 / (1 + this.sinc0 * sinc + this.cosc0 * cosc * cosl);
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p.x = k * cosc * Math.sin(p.x);
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p.y = k * (this.cosc0 * sinc - this.sinc0 * cosc * cosl);
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p.x = this.a * p.x + this.x0;
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p.y = this.a * p.y + this.y0;
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return p;
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};
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exports.inverse = function(p) {
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var sinc, cosc, lon, lat, rho;
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p.x = (p.x - this.x0) / this.a;
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p.y = (p.y - this.y0) / this.a;
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p.x /= this.k0;
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p.y /= this.k0;
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if ((rho = Math.sqrt(p.x * p.x + p.y * p.y))) {
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var c = 2 * Math.atan2(rho, this.R2);
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sinc = Math.sin(c);
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cosc = Math.cos(c);
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lat = Math.asin(cosc * this.sinc0 + p.y * sinc * this.cosc0 / rho);
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lon = Math.atan2(p.x * sinc, rho * this.cosc0 * cosc - p.y * this.sinc0 * sinc);
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}
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else {
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lat = this.phic0;
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lon = 0;
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}
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p.x = lon;
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p.y = lat;
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gauss.inverse.apply(this, [p]);
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p.x = adjust_lon(p.x + this.long0);
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return p;
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};
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exports.names = ["Stereographic_North_Pole", "Oblique_Stereographic", "Polar_Stereographic", "sterea","Oblique Stereographic Alternative"];
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