@antv/scale
Version:
Toolkit for mapping abstract data into visual representation.
57 lines • 1.84 kB
JavaScript
;
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;
//# sourceMappingURL=r-pretty.js.map