421 lines
12 KiB
JavaScript
421 lines
12 KiB
JavaScript
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// https://d3js.org/d3-contour/ v4.0.2 Copyright 2012-2023 Mike Bostock
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(function (global, factory) {
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typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('d3-array')) :
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typeof define === 'function' && define.amd ? define(['exports', 'd3-array'], factory) :
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(global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.d3 = global.d3 || {}, global.d3));
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})(this, (function (exports, d3Array) { 'use strict';
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var array = Array.prototype;
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var slice = array.slice;
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function ascending(a, b) {
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return a - b;
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}
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function area(ring) {
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var i = 0, n = ring.length, area = ring[n - 1][1] * ring[0][0] - ring[n - 1][0] * ring[0][1];
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while (++i < n) area += ring[i - 1][1] * ring[i][0] - ring[i - 1][0] * ring[i][1];
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return area;
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}
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var constant = x => () => x;
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function contains(ring, hole) {
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var i = -1, n = hole.length, c;
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while (++i < n) if (c = ringContains(ring, hole[i])) return c;
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return 0;
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}
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function ringContains(ring, point) {
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var x = point[0], y = point[1], contains = -1;
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for (var i = 0, n = ring.length, j = n - 1; i < n; j = i++) {
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var pi = ring[i], xi = pi[0], yi = pi[1], pj = ring[j], xj = pj[0], yj = pj[1];
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if (segmentContains(pi, pj, point)) return 0;
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if (((yi > y) !== (yj > y)) && ((x < (xj - xi) * (y - yi) / (yj - yi) + xi))) contains = -contains;
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}
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return contains;
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}
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function segmentContains(a, b, c) {
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var i; return collinear(a, b, c) && within(a[i = +(a[0] === b[0])], c[i], b[i]);
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}
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function collinear(a, b, c) {
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return (b[0] - a[0]) * (c[1] - a[1]) === (c[0] - a[0]) * (b[1] - a[1]);
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}
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function within(p, q, r) {
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return p <= q && q <= r || r <= q && q <= p;
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}
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function noop() {}
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var cases = [
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[],
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[[[1.0, 1.5], [0.5, 1.0]]],
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[[[1.5, 1.0], [1.0, 1.5]]],
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[[[1.5, 1.0], [0.5, 1.0]]],
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[[[1.0, 0.5], [1.5, 1.0]]],
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[[[1.0, 1.5], [0.5, 1.0]], [[1.0, 0.5], [1.5, 1.0]]],
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[[[1.0, 0.5], [1.0, 1.5]]],
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[[[1.0, 0.5], [0.5, 1.0]]],
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[[[0.5, 1.0], [1.0, 0.5]]],
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[[[1.0, 1.5], [1.0, 0.5]]],
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[[[0.5, 1.0], [1.0, 0.5]], [[1.5, 1.0], [1.0, 1.5]]],
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[[[1.5, 1.0], [1.0, 0.5]]],
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[[[0.5, 1.0], [1.5, 1.0]]],
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[[[1.0, 1.5], [1.5, 1.0]]],
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[[[0.5, 1.0], [1.0, 1.5]]],
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[]
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];
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function Contours() {
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var dx = 1,
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dy = 1,
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threshold = d3Array.thresholdSturges,
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smooth = smoothLinear;
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function contours(values) {
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var tz = threshold(values);
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// Convert number of thresholds into uniform thresholds.
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if (!Array.isArray(tz)) {
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const e = d3Array.extent(values, finite);
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tz = d3Array.ticks(...d3Array.nice(e[0], e[1], tz), tz);
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while (tz[tz.length - 1] >= e[1]) tz.pop();
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while (tz[1] < e[0]) tz.shift();
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} else {
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tz = tz.slice().sort(ascending);
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}
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return tz.map(value => contour(values, value));
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}
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// Accumulate, smooth contour rings, assign holes to exterior rings.
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// Based on https://github.com/mbostock/shapefile/blob/v0.6.2/shp/polygon.js
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function contour(values, value) {
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const v = value == null ? NaN : +value;
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if (isNaN(v)) throw new Error(`invalid value: ${value}`);
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var polygons = [],
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holes = [];
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isorings(values, v, function(ring) {
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smooth(ring, values, v);
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if (area(ring) > 0) polygons.push([ring]);
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else holes.push(ring);
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});
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holes.forEach(function(hole) {
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for (var i = 0, n = polygons.length, polygon; i < n; ++i) {
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if (contains((polygon = polygons[i])[0], hole) !== -1) {
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polygon.push(hole);
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return;
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}
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}
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});
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return {
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type: "MultiPolygon",
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value: value,
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coordinates: polygons
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};
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}
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// Marching squares with isolines stitched into rings.
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// Based on https://github.com/topojson/topojson-client/blob/v3.0.0/src/stitch.js
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function isorings(values, value, callback) {
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var fragmentByStart = new Array,
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fragmentByEnd = new Array,
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x, y, t0, t1, t2, t3;
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// Special case for the first row (y = -1, t2 = t3 = 0).
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x = y = -1;
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t1 = above(values[0], value);
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cases[t1 << 1].forEach(stitch);
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while (++x < dx - 1) {
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t0 = t1, t1 = above(values[x + 1], value);
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cases[t0 | t1 << 1].forEach(stitch);
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}
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cases[t1 << 0].forEach(stitch);
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// General case for the intermediate rows.
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while (++y < dy - 1) {
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x = -1;
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t1 = above(values[y * dx + dx], value);
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t2 = above(values[y * dx], value);
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cases[t1 << 1 | t2 << 2].forEach(stitch);
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while (++x < dx - 1) {
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t0 = t1, t1 = above(values[y * dx + dx + x + 1], value);
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t3 = t2, t2 = above(values[y * dx + x + 1], value);
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cases[t0 | t1 << 1 | t2 << 2 | t3 << 3].forEach(stitch);
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}
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cases[t1 | t2 << 3].forEach(stitch);
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}
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// Special case for the last row (y = dy - 1, t0 = t1 = 0).
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x = -1;
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t2 = values[y * dx] >= value;
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cases[t2 << 2].forEach(stitch);
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while (++x < dx - 1) {
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t3 = t2, t2 = above(values[y * dx + x + 1], value);
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cases[t2 << 2 | t3 << 3].forEach(stitch);
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}
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cases[t2 << 3].forEach(stitch);
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function stitch(line) {
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var start = [line[0][0] + x, line[0][1] + y],
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end = [line[1][0] + x, line[1][1] + y],
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startIndex = index(start),
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endIndex = index(end),
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f, g;
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if (f = fragmentByEnd[startIndex]) {
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if (g = fragmentByStart[endIndex]) {
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delete fragmentByEnd[f.end];
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delete fragmentByStart[g.start];
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if (f === g) {
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f.ring.push(end);
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callback(f.ring);
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} else {
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fragmentByStart[f.start] = fragmentByEnd[g.end] = {start: f.start, end: g.end, ring: f.ring.concat(g.ring)};
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}
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} else {
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delete fragmentByEnd[f.end];
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f.ring.push(end);
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fragmentByEnd[f.end = endIndex] = f;
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}
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} else if (f = fragmentByStart[endIndex]) {
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if (g = fragmentByEnd[startIndex]) {
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delete fragmentByStart[f.start];
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delete fragmentByEnd[g.end];
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if (f === g) {
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f.ring.push(end);
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callback(f.ring);
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} else {
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fragmentByStart[g.start] = fragmentByEnd[f.end] = {start: g.start, end: f.end, ring: g.ring.concat(f.ring)};
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}
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} else {
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delete fragmentByStart[f.start];
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f.ring.unshift(start);
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fragmentByStart[f.start = startIndex] = f;
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}
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} else {
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fragmentByStart[startIndex] = fragmentByEnd[endIndex] = {start: startIndex, end: endIndex, ring: [start, end]};
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}
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}
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}
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function index(point) {
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return point[0] * 2 + point[1] * (dx + 1) * 4;
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}
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function smoothLinear(ring, values, value) {
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ring.forEach(function(point) {
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var x = point[0],
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y = point[1],
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xt = x | 0,
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yt = y | 0,
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v1 = valid(values[yt * dx + xt]);
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if (x > 0 && x < dx && xt === x) {
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point[0] = smooth1(x, valid(values[yt * dx + xt - 1]), v1, value);
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}
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if (y > 0 && y < dy && yt === y) {
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point[1] = smooth1(y, valid(values[(yt - 1) * dx + xt]), v1, value);
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}
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});
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}
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contours.contour = contour;
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contours.size = function(_) {
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if (!arguments.length) return [dx, dy];
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var _0 = Math.floor(_[0]), _1 = Math.floor(_[1]);
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if (!(_0 >= 0 && _1 >= 0)) throw new Error("invalid size");
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return dx = _0, dy = _1, contours;
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};
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contours.thresholds = function(_) {
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return arguments.length ? (threshold = typeof _ === "function" ? _ : Array.isArray(_) ? constant(slice.call(_)) : constant(_), contours) : threshold;
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};
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contours.smooth = function(_) {
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return arguments.length ? (smooth = _ ? smoothLinear : noop, contours) : smooth === smoothLinear;
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};
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return contours;
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}
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// When computing the extent, ignore infinite values (as well as invalid ones).
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function finite(x) {
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return isFinite(x) ? x : NaN;
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}
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// Is the (possibly invalid) x greater than or equal to the (known valid) value?
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// Treat any invalid value as below negative infinity.
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function above(x, value) {
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return x == null ? false : +x >= value;
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}
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// During smoothing, treat any invalid value as negative infinity.
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function valid(v) {
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return v == null || isNaN(v = +v) ? -Infinity : v;
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}
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function smooth1(x, v0, v1, value) {
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const a = value - v0;
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const b = v1 - v0;
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const d = isFinite(a) || isFinite(b) ? a / b : Math.sign(a) / Math.sign(b);
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return isNaN(d) ? x : x + d - 0.5;
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}
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function defaultX(d) {
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return d[0];
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}
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function defaultY(d) {
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return d[1];
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}
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function defaultWeight() {
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return 1;
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}
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function density() {
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var x = defaultX,
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y = defaultY,
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weight = defaultWeight,
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dx = 960,
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dy = 500,
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r = 20, // blur radius
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k = 2, // log2(grid cell size)
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o = r * 3, // grid offset, to pad for blur
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n = (dx + o * 2) >> k, // grid width
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m = (dy + o * 2) >> k, // grid height
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threshold = constant(20);
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function grid(data) {
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var values = new Float32Array(n * m),
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pow2k = Math.pow(2, -k),
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i = -1;
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for (const d of data) {
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var xi = (x(d, ++i, data) + o) * pow2k,
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yi = (y(d, i, data) + o) * pow2k,
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wi = +weight(d, i, data);
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if (wi && xi >= 0 && xi < n && yi >= 0 && yi < m) {
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var x0 = Math.floor(xi),
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y0 = Math.floor(yi),
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xt = xi - x0 - 0.5,
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yt = yi - y0 - 0.5;
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values[x0 + y0 * n] += (1 - xt) * (1 - yt) * wi;
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values[x0 + 1 + y0 * n] += xt * (1 - yt) * wi;
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values[x0 + 1 + (y0 + 1) * n] += xt * yt * wi;
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values[x0 + (y0 + 1) * n] += (1 - xt) * yt * wi;
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}
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}
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d3Array.blur2({data: values, width: n, height: m}, r * pow2k);
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return values;
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}
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function density(data) {
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var values = grid(data),
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tz = threshold(values),
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pow4k = Math.pow(2, 2 * k);
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// Convert number of thresholds into uniform thresholds.
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if (!Array.isArray(tz)) {
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tz = d3Array.ticks(Number.MIN_VALUE, d3Array.max(values) / pow4k, tz);
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}
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return Contours()
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.size([n, m])
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.thresholds(tz.map(d => d * pow4k))
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(values)
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.map((c, i) => (c.value = +tz[i], transform(c)));
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}
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density.contours = function(data) {
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var values = grid(data),
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contours = Contours().size([n, m]),
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pow4k = Math.pow(2, 2 * k),
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contour = value => {
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value = +value;
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var c = transform(contours.contour(values, value * pow4k));
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c.value = value; // preserve exact threshold value
|
||
|
|
return c;
|
||
|
|
};
|
||
|
|
Object.defineProperty(contour, "max", {get: () => d3Array.max(values) / pow4k});
|
||
|
|
return contour;
|
||
|
|
};
|
||
|
|
|
||
|
|
function transform(geometry) {
|
||
|
|
geometry.coordinates.forEach(transformPolygon);
|
||
|
|
return geometry;
|
||
|
|
}
|
||
|
|
|
||
|
|
function transformPolygon(coordinates) {
|
||
|
|
coordinates.forEach(transformRing);
|
||
|
|
}
|
||
|
|
|
||
|
|
function transformRing(coordinates) {
|
||
|
|
coordinates.forEach(transformPoint);
|
||
|
|
}
|
||
|
|
|
||
|
|
// TODO Optimize.
|
||
|
|
function transformPoint(coordinates) {
|
||
|
|
coordinates[0] = coordinates[0] * Math.pow(2, k) - o;
|
||
|
|
coordinates[1] = coordinates[1] * Math.pow(2, k) - o;
|
||
|
|
}
|
||
|
|
|
||
|
|
function resize() {
|
||
|
|
o = r * 3;
|
||
|
|
n = (dx + o * 2) >> k;
|
||
|
|
m = (dy + o * 2) >> k;
|
||
|
|
return density;
|
||
|
|
}
|
||
|
|
|
||
|
|
density.x = function(_) {
|
||
|
|
return arguments.length ? (x = typeof _ === "function" ? _ : constant(+_), density) : x;
|
||
|
|
};
|
||
|
|
|
||
|
|
density.y = function(_) {
|
||
|
|
return arguments.length ? (y = typeof _ === "function" ? _ : constant(+_), density) : y;
|
||
|
|
};
|
||
|
|
|
||
|
|
density.weight = function(_) {
|
||
|
|
return arguments.length ? (weight = typeof _ === "function" ? _ : constant(+_), density) : weight;
|
||
|
|
};
|
||
|
|
|
||
|
|
density.size = function(_) {
|
||
|
|
if (!arguments.length) return [dx, dy];
|
||
|
|
var _0 = +_[0], _1 = +_[1];
|
||
|
|
if (!(_0 >= 0 && _1 >= 0)) throw new Error("invalid size");
|
||
|
|
return dx = _0, dy = _1, resize();
|
||
|
|
};
|
||
|
|
|
||
|
|
density.cellSize = function(_) {
|
||
|
|
if (!arguments.length) return 1 << k;
|
||
|
|
if (!((_ = +_) >= 1)) throw new Error("invalid cell size");
|
||
|
|
return k = Math.floor(Math.log(_) / Math.LN2), resize();
|
||
|
|
};
|
||
|
|
|
||
|
|
density.thresholds = function(_) {
|
||
|
|
return arguments.length ? (threshold = typeof _ === "function" ? _ : Array.isArray(_) ? constant(slice.call(_)) : constant(_), density) : threshold;
|
||
|
|
};
|
||
|
|
|
||
|
|
density.bandwidth = function(_) {
|
||
|
|
if (!arguments.length) return Math.sqrt(r * (r + 1));
|
||
|
|
if (!((_ = +_) >= 0)) throw new Error("invalid bandwidth");
|
||
|
|
return r = (Math.sqrt(4 * _ * _ + 1) - 1) / 2, resize();
|
||
|
|
};
|
||
|
|
|
||
|
|
return density;
|
||
|
|
}
|
||
|
|
|
||
|
|
exports.contourDensity = density;
|
||
|
|
exports.contours = Contours;
|
||
|
|
|
||
|
|
}));
|