Sha256: ed34ac4687d89d9db27b542fcbeb66a58edce10d693e0de0c784c45ffb6c353a
Contents?: true
Size: 742 Bytes
Versions: 2
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Stored size: 742 Bytes
Contents
function vanDerGrinten3(λ, φ) {
if (Math.abs(φ) < ε) return [λ, 0];
var sinθ = 2 * φ / π,
θ = asin(sinθ);
if (Math.abs(λ) < ε || Math.abs(Math.abs(φ) - π / 2) < ε) return [0, π * Math.tan(θ / 2)];
var A = (π / λ - λ / π) / 2,
y1 = sinθ / (1 + Math.cos(θ));
return [
π * (sgn(λ) * asqrt(A * A + 1 - y1 * y1) - A),
π * y1
];
}
vanDerGrinten3.invert = function(x, y) {
if (!y) return [x, 0];
var y1 = y / π,
A = (π * π * (1 - y1 * y1) - x * x) / (2 * π * x);
return [
x ? π * (sgn(x) * Math.sqrt(A * A + 1) - A) : 0,
π / 2 * Math.sin(2 * Math.atan(y1))
];
};
(d3.geo.vanDerGrinten3 = function() { return projection(vanDerGrinten3); }).raw = vanDerGrinten3;
Version data entries
2 entries across 2 versions & 1 rubygems