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54 lines
1.6 KiB
54 lines
1.6 KiB
import { identity } from '@antv/util';
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import { Continuous } from './continuous';
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import { createInterpolateValue } from '../utils';
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import { d3Ticks } from '../tick-methods/d3-ticks';
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const transformPow = (exponent) => {
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return (x) => {
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return x < 0 ? -((-x) ** exponent) : x ** exponent;
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};
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};
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const transformPowInvert = (exponent) => {
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return (x) => {
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return x < 0 ? -((-x) ** (1 / exponent)) : x ** (1 / exponent);
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};
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};
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const transformSqrt = (x) => {
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return x < 0 ? -Math.sqrt(-x) : Math.sqrt(x);
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};
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/**
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* Pow 比例尺
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*
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* 类似于 linear scale, 不同之处在于在计算输出范围值之前对输入域值应用了指数变换,.
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* 即 y = x ^ k 其中 k（指数）可以是任何实数。
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*/
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export class Pow extends Continuous {
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getDefaultOptions() {
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return {
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domain: [0, 1],
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range: [0, 1],
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nice: false,
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clamp: false,
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round: false,
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exponent: 2,
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interpolate: createInterpolateValue,
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tickMethod: d3Ticks,
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tickCount: 5,
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};
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}
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// 显示指定 options 的类型为 PowOptions O 的类型
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constructor(options) {
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super(options);
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}
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chooseTransforms() {
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const { exponent } = this.options;
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if (exponent === 1)
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return [identity, identity];
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const transform = exponent === 0.5 ? transformSqrt : transformPow(exponent);
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const untransform = transformPowInvert(exponent);
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return [transform, untransform];
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}
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clone() {
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return new Pow(this.options);
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}
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}
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//# sourceMappingURL=pow.js.map
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