32 lines
899 B
TypeScript
32 lines
899 B
TypeScript
import { isEmpty } from '@antv/util';
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import { ScaleConfig } from '../types';
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import { getLogPositiveMin, log } from '../util/math';
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/**
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* 计算 log 的 ticks，考虑 min = 0 的场景
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* @param cfg 度量的配置项
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* @returns 计算后的 ticks
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*/
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export default function calculateLogTicks(cfg: ScaleConfig) {
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const { base, tickCount, min, max, values } = cfg;
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let minTick;
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const maxTick = log(base, max);
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if (min > 0) {
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minTick = Math.floor(log(base, min));
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} else {
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const positiveMin = getLogPositiveMin(values, base, max);
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minTick = Math.floor(log(base, positiveMin));
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}
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const count = maxTick - minTick;
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const avg = Math.ceil(count / tickCount);
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const ticks = [];
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for (let i = minTick; i < maxTick + avg; i = i + avg) {
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ticks.push(Math.pow(base, i));
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}
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if (min <= 0) {
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// 最小值 <= 0 时显示 0
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ticks.unshift(0);
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}
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return ticks;
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}
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