@antv/scale
Version:
Toolkit for mapping abstract data into visual representation.
152 lines • 5.88 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.wilkinsonExtended = exports.ALL_Q = exports.DEFAULT_Q = void 0;
const util_1 = require("@antv/util");
const pretty_number_1 = require("../utils/pretty-number");
exports.DEFAULT_Q = [1, 5, 2, 2.5, 4, 3];
exports.ALL_Q = [1, 5, 2, 2.5, 4, 3, 1.5, 7, 6, 8, 9];
const eps = Number.EPSILON * 100;
function mod(n, m) {
return ((n % m) + m) % m;
}
function round(n) {
return Math.round(n * 1e12) / 1e12;
}
function simplicity(q, Q, j, lmin, lmax, lstep) {
const n = (0, util_1.size)(Q);
const i = (0, util_1.indexOf)(Q, q);
let v = 0;
const m = mod(lmin, lstep);
if ((m < eps || lstep - m < eps) && lmin <= 0 && lmax >= 0) {
v = 1;
}
return 1 - i / (n - 1) - j + v;
}
function simplicityMax(q, Q, j) {
const n = (0, util_1.size)(Q);
const i = (0, util_1.indexOf)(Q, q);
const v = 1;
return 1 - i / (n - 1) - j + v;
}
function density(k, m, dMin, dMax, lMin, lMax) {
const r = (k - 1) / (lMax - lMin);
const rt = (m - 1) / (Math.max(lMax, dMax) - Math.min(dMin, lMin));
return 2 - Math.max(r / rt, rt / r);
}
function densityMax(k, m) {
if (k >= m) {
return 2 - (k - 1) / (m - 1);
}
return 1;
}
function coverage(dMin, dMax, lMin, lMax) {
const range = dMax - dMin;
return 1 - (0.5 * ((dMax - lMax) ** 2 + (dMin - lMin) ** 2)) / (0.1 * range) ** 2;
}
function coverageMax(dMin, dMax, span) {
const range = dMax - dMin;
if (span > range) {
const half = (span - range) / 2;
return 1 - half ** 2 / (0.1 * range) ** 2;
}
return 1;
}
function legibility() {
return 1;
}
/**
* An Extension of Wilkinson's Algorithm for Position Tick Labels on Axes
* https://www.yuque.com/preview/yuque/0/2019/pdf/185317/1546999150858-45c3b9c2-4e86-4223-bf1a-8a732e8195ed.pdf
* @param dMin 最小值
* @param dMax 最大值
* @param m tick个数
* @param onlyLoose 是否允许扩展min、max，不绝对强制，例如[3, 97]
* @param Q nice numbers集合
* @param w 四个优化组件的权重
*/
const wilkinsonExtended = (dMin, dMax, n = 5, onlyLoose = true, Q = exports.DEFAULT_Q, w = [0.25, 0.2, 0.5, 0.05]) => {
const m = n < 0 ? 0 : Math.round(n);
// nan 也会导致异常
if (Number.isNaN(dMin) || Number.isNaN(dMax) || typeof dMin !== 'number' || typeof dMax !== 'number' || !m) {
return [];
}
// js 极大值极小值问题，差值小于 1e-15 会导致计算出错
if (dMax - dMin < 1e-15 || m === 1) {
return [dMin];
}
const best = {
score: -2,
lmin: 0,
lmax: 0,
lstep: 0,
};
let j = 1;
while (j < Infinity) {
// for (const q of Q)
for (let i = 0; i < Q.length; i += 1) {
const q = Q[i];
const sm = simplicityMax(q, Q, j);
if (w[0] * sm + w[1] + w[2] + w[3] < best.score) {
j = Infinity;
break;
}
let k = 2;
while (k < Infinity) {
const dm = densityMax(k, m);
if (w[0] * sm + w[1] + w[2] * dm + w[3] < best.score) {
break;
}
const delta = (dMax - dMin) / (k + 1) / j / q;
let z = Math.ceil(Math.log10(delta));
while (z < Infinity) {
const step = j * q * 10 ** z;
const cm = coverageMax(dMin, dMax, step * (k - 1));
if (w[0] * sm + w[1] * cm + w[2] * dm + w[3] < best.score) {
break;
}
const minStart = Math.floor(dMax / step) * j - (k - 1) * j;
const maxStart = Math.ceil(dMin / step) * j;
if (minStart <= maxStart) {
const count = maxStart - minStart;
for (let i = 0; i <= count; i += 1) {
const start = minStart + i;
const lMin = start * (step / j);
const lMax = lMin + step * (k - 1);
const lStep = step;
const s = simplicity(q, Q, j, lMin, lMax, lStep);
const c = coverage(dMin, dMax, lMin, lMax);
const g = density(k, m, dMin, dMax, lMin, lMax);
const l = legibility();
const score = w[0] * s + w[1] * c + w[2] * g + w[3] * l;
if (score > best.score && (!onlyLoose || (lMin <= dMin && lMax >= dMax))) {
best.lmin = lMin;
best.lmax = lMax;
best.lstep = lStep;
best.score = score;
}
}
}
z += 1;
}
k += 1;
}
}
j += 1;
}
// 处理精度问题，保证这三个数没有精度问题
const lmax = (0, pretty_number_1.prettyNumber)(best.lmax);
const lmin = (0, pretty_number_1.prettyNumber)(best.lmin);
const lstep = (0, pretty_number_1.prettyNumber)(best.lstep);
// 加 round 是为处理 extended(0.94, 1, 5)
// 保证生成的 tickCount 没有精度问题
const tickCount = Math.floor(round((lmax - lmin) / lstep)) + 1;
const ticks = new Array(tickCount);
// 少用乘法：防止出现 -1.2 + 1.2 * 3 = 2.3999999999999995 的情况
ticks[0] = (0, pretty_number_1.prettyNumber)(lmin);
for (let i = 1; i < tickCount; i += 1) {
ticks[i] = (0, pretty_number_1.prettyNumber)(ticks[i - 1] + lstep);
}
return ticks;
};
exports.wilkinsonExtended = wilkinsonExtended;
//# sourceMappingURL=wilkinson-extended.js.map