@antv/scale/lib/tick-methods/r-pretty.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.rPretty = void 0;
const pretty_number_1 = require("../utils/pretty-number");
/**
 * 创建分割点
 * @param min 左区间
 * @param max 右区间
 * @param n 分割点个数
 * @returns 计算后的 ticks
 * @see R pretty https://svn.r-project.org/R/trunk/src/appl/pretty.c
 * @see R pretty https://www.rdocumentation.org/packages/base/versions/3.5.2/topics/pretty
 */
const rPretty = (min, max, m = 5) => {
    if (min === max) {
        return [min];
    }
    const n = m < 0 ? 0 : Math.round(m);
    if (n === 0)
        return [];
    // high.u.bias
    const h = 1.5;
    // u5.bias
    const h5 = 0.5 + 1.5 * h;
    // 反正我也不会调参，跳过所有判断步骤
    const d = max - min;
    const c = d / n;
    // 当d非常小的时候触发，但似乎没什么用
    // const min_n = Math.floor(n / 3);
    // const shrink_sml = Math.pow(2, 5);
    // if (Math.log10(d) < -2) {
    //   c = (_.max([ Math.abs(max), Math.abs(min) ]) * shrink_sml) / min_n;
    // }
    const base = 10 ** Math.floor(Math.log10(c));
    let unit = base;
    if (2 * base - c < h * (c - unit)) {
        unit = 2 * base;
        if (5 * base - c < h5 * (c - unit)) {
            unit = 5 * base;
            if (10 * base - c < h * (c - unit)) {
                unit = 10 * base;
            }
        }
    }
    const nu = Math.ceil(max / unit);
    const ns = Math.floor(min / unit);
    const hi = Math.max(nu * unit, max);
    const lo = Math.min(ns * unit, min);
    const size = Math.floor((hi - lo) / unit) + 1;
    const ticks = new Array(size);
    for (let i = 0; i < size; i += 1) {
        ticks[i] = (0, pretty_number_1.prettyNumber)(lo + i * unit);
    }
    return ticks;
};
exports.rPretty = rPretty;
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