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24 lines
493 B
24 lines
493 B
import {geoProjection as projection} from "d3-geo";
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import {abs, pi, sqrt} from "./math.js";
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export function eckert1Raw(lambda, phi) {
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var alpha = sqrt(8 / (3 * pi));
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return [
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alpha * lambda * (1 - abs(phi) / pi),
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alpha * phi
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];
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}
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eckert1Raw.invert = function(x, y) {
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var alpha = sqrt(8 / (3 * pi)),
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phi = y / alpha;
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return [
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x / (alpha * (1 - abs(phi) / pi)),
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phi
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];
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};
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export default function() {
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return projection(eckert1Raw)
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.scale(165.664);
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}
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