import “../math/trigonometry”; import “geo”; import “conic”; import “projection”;
function d3_geo_conicEqualArea(φ0, φ1) {
var sinφ0 = Math.sin(φ0), n = (sinφ0 + Math.sin(φ1)) / 2, C = 1 + sinφ0 * (2 * n - sinφ0), ρ0 = Math.sqrt(C) / n; function forward(λ, φ) { var ρ = Math.sqrt(C - 2 * n * Math.sin(φ)) / n; return [ ρ * Math.sin(λ *= n), ρ0 - ρ * Math.cos(λ) ]; } forward.invert = function(x, y) { var ρ0_y = ρ0 - y; return [ Math.atan2(x, ρ0_y) / n, d3_asin((C - (x * x + ρ0_y * ρ0_y) * n * n) / (2 * n)) ]; }; return forward;
}
(d3.geo.conicEqualArea = function() {
return d3_geo_conic(d3_geo_conicEqualArea);
}).raw = d3_geo_conicEqualArea;