Sha256: edc656e1805cc75661fa9bbaefa7affb5a06f60eee1d7c1e065f161c22d1da8f
Contents?: true
Size: 962 Bytes
Versions: 4
Compression:
Stored size: 962 Bytes
Contents
import "../math/trigonometry";
import "conic";
import "geo";
import "projection";
function d3_geo_conicConformal(φ0, φ1) {
var cosφ0 = Math.cos(φ0),
t = function(φ) { return Math.tan(π / 4 + φ / 2); },
n = φ0 === φ1 ? Math.sin(φ0) : Math.log(cosφ0 / Math.cos(φ1)) / Math.log(t(φ1) / t(φ0)),
F = cosφ0 * Math.pow(t(φ0), n) / n;
if (!n) return d3_geo_mercator;
function forward(λ, φ) {
var ρ = Math.abs(Math.abs(φ) - π / 2) < ε ? 0 : F / Math.pow(t(φ), n);
return [
ρ * Math.sin(n * λ),
F - ρ * Math.cos(n * λ)
];
}
forward.invert = function(x, y) {
var ρ0_y = F - y,
ρ = d3_sgn(n) * Math.sqrt(x * x + ρ0_y * ρ0_y);
return [
Math.atan2(x, ρ0_y) / n,
2 * Math.atan(Math.pow(F / ρ, 1 / n)) - π / 2
];
};
return forward;
}
(d3.geo.conicConformal = function() {
return d3_geo_conic(d3_geo_conicConformal);
}).raw = d3_geo_conicConformal;
Version data entries
4 entries across 4 versions & 2 rubygems