51 lines
1.2 KiB
JavaScript
51 lines
1.2 KiB
JavaScript
import {linearish} from "./linear.js";
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import {copy, identity, transformer} from "./continuous.js";
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import {initRange} from "./init.js";
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function transformPow(exponent) {
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return function(x) {
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return x < 0 ? -Math.pow(-x, exponent) : Math.pow(x, exponent);
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};
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}
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function transformSqrt(x) {
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return x < 0 ? -Math.sqrt(-x) : Math.sqrt(x);
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}
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function transformSquare(x) {
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return x < 0 ? -x * x : x * x;
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}
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export function powish(transform) {
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var scale = transform(identity, identity),
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exponent = 1;
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function rescale() {
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return exponent === 1 ? transform(identity, identity)
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: exponent === 0.5 ? transform(transformSqrt, transformSquare)
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: transform(transformPow(exponent), transformPow(1 / exponent));
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}
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scale.exponent = function(_) {
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return arguments.length ? (exponent = +_, rescale()) : exponent;
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};
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return linearish(scale);
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}
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export default function pow() {
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var scale = powish(transformer());
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scale.copy = function() {
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return copy(scale, pow()).exponent(scale.exponent());
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};
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initRange.apply(scale, arguments);
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return scale;
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}
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export function sqrt() {
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return pow.apply(null, arguments).exponent(0.5);
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}
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