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