Sha256: 2d319123d9f7653bb8a44c6b109bd862b2a4ac7eb8bd52d93b554a7a970762e7
Contents?: true
Size: 893 Bytes
Versions: 4
Compression:
Stored size: 893 Bytes
Contents
import "projection";
function naturalEarth(λ, φ) {
var φ2 = φ * φ, φ4 = φ2 * φ2;
return [
λ * (.8707 - .131979 * φ2 + φ4 * (-.013791 + φ4 * (.003971 * φ2 - .001529 * φ4))),
φ * (1.007226 + φ2 * (.015085 + φ4 * (-.044475 + .028874 * φ2 - .005916 * φ4)))
];
}
naturalEarth.invert = function(x, y) {
var φ = y, i = 25, δ;
do {
var φ2 = φ * φ, φ4 = φ2 * φ2;
φ -= δ = (φ * (1.007226 + φ2 * (.015085 + φ4 * (-.044475 + .028874 * φ2 - .005916 * φ4))) - y) /
(1.007226 + φ2 * (.015085 * 3 + φ4 * (-.044475 * 7 + .028874 * 9 * φ2 - .005916 * 11 * φ4)));
} while (Math.abs(δ) > ε && --i > 0);
return [
x / (.8707 + (φ2 = φ * φ) * (-.131979 + φ2 * (-.013791 + φ2 * φ2 * φ2 * (.003971 - .001529 * φ2)))),
φ
];
};
(d3.geo.naturalEarth = function() { return projection(naturalEarth); }).raw = naturalEarth;
Version data entries
4 entries across 4 versions & 1 rubygems