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43 lines
1.2 KiB
43 lines
1.2 KiB
import { Base } from './base';
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import { bisect, isValid } from '../utils';
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/**
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* 将连续的定义域分段，每一段所有的值对应离散的值域中一个值
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*/
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export class Threshold extends Base {
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getDefaultOptions() {
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return {
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domain: [0.5],
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range: [0, 1],
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};
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}
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constructor(options) {
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super(options);
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}
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/**
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* 二分查找到输入值在哪一段，返回对应的值域中的值
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*/
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map(x) {
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if (!isValid(x))
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return this.options.unknown;
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const index = bisect(this.thresholds, x, 0, this.n);
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return this.options.range[index];
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}
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/**
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* 在值域中找到对应的值，并返回在定义域中属于哪一段
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*/
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invert(y) {
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const { range } = this.options;
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const index = range.indexOf(y);
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const domain = this.thresholds;
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return [domain[index - 1], domain[index]];
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}
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clone() {
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return new Threshold(this.options);
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}
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rescale() {
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const { domain, range } = this.options;
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this.n = Math.min(domain.length, range.length - 1);
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this.thresholds = domain;
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}
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}
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//# sourceMappingURL=threshold.js.map
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