function stabWernerRaw(ratio, max) {
/*
* simplified Bonne, with phi0 = halfPi ;
* https://github.com/d3/d3-geo-projection/blob/master/src/bonne.js
*/
function r(lambda, phi) {
const rho = halfPi - phi,
e = rho ? (lambda * cos(phi)) / rho : rho;
return [rho * sin(e), -rho * cos(e)];
}
r.invert = function(x, y) {
var rho = sqrt(x ** 2 + y ** 2),
phi = halfPi - rho;
return [(rho / cos(phi)) * atan2(x, -y), phi];
};
/* azimuthal equidistant for the pole part */
const az = d3
.geoAzimuthalEquidistant()
.rotate([0, -90])
.translate([0, 0])
.scale(1);
/* mix */
function forward(lambda, phi) {
if (phi < max * radians) {
lambda *= ratio;
return r(lambda, phi);
} else {
const p = az([lambda * degrees, phi * degrees]);
return [p[0], -p[1]];
}
}
function invert(x, y) {
let i = az.invert([x, -y]);
if (i[1] < max) {
i = r.invert(x, y);
i[0] /= ratio;
} else {
i[0] *= radians;
i[1] *= radians;
}
return [i[0], i[1]];
}
forward.invert = invert;
return forward;
}
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Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
