2e:null 2f:["$","title",null,{"children":"Maxwell–Boltzmann distribution | Davi Ortega | Observable"}] 34:Tb70,run = () => { const histRange = 2 const ticks = 100 d3.select('#sim').selectAll('circle').remove() d3.select('#hist').selectAll('g').remove() const init = initialData() const nodes = d3.select('#sim').selectAll('circle') const simulation = d3.forceSimulation(init) .velocityDecay(0) .alphaDecay(0) // .force("charge", d3.forceManyBody().strength((d) => d.strength)) .force("bounce", d3.forceBounce().radius(params.r).elasticity(1)) .force("bounce-on-container", function () { for (var i = 0, n = init.length, node; i < n; ++i) { node = init[i]; const dx = (node.x + node.vx) // params.width - 1 / 2, const dy = (node.y + node.vy) // params.height - 1 / 2; if (dx > params.width || dx < 0) { node.vx *= -1; } if (dy > params.height || dy < 0) { node.vy *= -1; } } }) let infectedNum = 1 /*const spread = () => { // console.log(infectedNum) //if (infectedNum < nodes.length / 2) { nodes.filter(d => d.infected) .each(d => { nodes .filter(n => (Math.abs(n.x - d.x) < 2 * params.r && Math.abs(n.y - d.y) < 2 * params.r && !n.infected && Math.random() < params.p)) .each(n => { n.infected = true; infectedNum++ }) }) }*/ const initSpeeds = init.map(p => Math.hypot(p.vx, p.vy)) const x = d3.scaleLinear() .domain([0, histRange]).nice() .range([0, params.histW]) const initBins = d3.histogram() .domain(x.domain()) .thresholds(x.ticks(ticks)) (initSpeeds) let y = d3.scaleLinear() .domain([0, d3.max(initBins, d => d.length)]).nice() .range([params.histH, 0]) const svg = d3.select('#hist') svg.append("g") .attr("fill", "steelblue") .selectAll("rect") .data(initBins) .join("rect") const updateHist = () => { const speeds = init.map(p => Math.hypot(p.vx, p.vy)) const bins = d3.histogram() .domain(x.domain()) .thresholds(x.ticks(ticks)) (speeds) y = d3.scaleLinear() .domain([0, d3.max(bins, d => d.length)]).nice() .range([params.histH, 0]) d3.select('#hist').select('g') .selectAll("rect") .data(bins) .transition() .attr("x", d => x(d.x0) + 1) .attr("width", d => Math.max(0, x(d.x1) - x(d.x0) - 1)) .attr("y", d => y(d.length)) .attr("height", d => y(0) - y(d.length)); } let rounds = 0 simulation.on('tick', () => { // spread() if (rounds % 50 === 0) { updateHist() } nodes .attr("cx", (d) => d.x) .attr("cy", (d) => d.y) // .style('opacity', d => d.infected ? 1 : 0) .style("fill", d => d.infected ? 'red' : 'black'); // calcAvgSpeed(speeds) rounds++ }) return simulation }35:[] 32:{"id":"4cec6aa3764a99d7","slug":"simulation","title":"Maxwell–Boltzmann distribution","thumbnail":"04f4cc92d88098622c63defa38bec1678e32ab1fc360d3d4c0d5891727a3dfab","access_level":"public","create_time":"$D2020-04-13T07:07:59.865Z","update_time":"$D2020-06-22T04:54:17.100Z","view_time":null,"first_public_time":"$D2020-05-10T19:17:52.392Z","has_unpublished_edits":null,"fork":false,"stars":3,"starred":false,"owner":{"type":"team","id":"92ee311a44ee7505","login":"daviortega","name":"Davi Ortega","avatar_url":"https://avatars-next.observableusercontent.com/5a0983d94c9bb9e0c1cc49b659f092376349a9ed0fb1967a9c8d98d4ea67af61","tier":"starter_2024"},"version":804,"publish_version":804,"role":null,"authored":false,"authors":[{"type":"individual","id":"61e7ac5783b2cc17","login":"daviortega","name":"Davi Ortega","avatar_url":"https://avatars-next.observableusercontent.com/5a0983d94c9bb9e0c1cc49b659f092376349a9ed0fb1967a9c8d98d4ea67af61","tier":null}],"members":[{"type":"individual","id":"61e7ac5783b2cc17","login":"daviortega","name":"Davi Ortega","avatar_url":"https://avatars-next.observableusercontent.com/5a0983d94c9bb9e0c1cc49b659f092376349a9ed0fb1967a9c8d98d4ea67af61","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":1,"collection":null,"type":"notebook","body":{"title":"Maxwell–Boltzmann distribution","cells":[{"id":0,"value":"md`# Maxwell–Boltzmann distribution`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":25,"value":"params = {\n return {\n N: 1000,\n width: 400,\n height:400,\n histH: 200,\n histW: 500,\n initSpeed: 0.8,\n r: 2,\n p: 0.05\n }\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":6,"value":"html `\n

\n \n \n

\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":122,"value":"sim = run()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":474,"value":"{\n const sick = initialData[0]\n \n const searchRadius = 5\n\n const quadtree = d3.quadtree()\n .x(d => d.x)\n .y(d => d.y)\n .addAll(initialData)\n \n console.log(quadtree)\n \n const isCloseEnough = (node) => {\n return Math.sqrt(Math.pow(node.x - sick.x) + Math.pow(node.y - sick.y)) < searchRadius\n }\n \n const closeNodes = []\n \n let i = 0\n quadtree.visit((node, x0, y0, x1, y1) => {\n console.log(`counter: ${i}`)\n console.log(`hey: ${x0}, ${y0}, ${x1}, ${y1}`)\n console.log(node)\n if (!node.length) { \n if (isCloseEnough(node)) {\n d3.select(`#p${i}`)\n .attr('fill', 'green')\n }\n }\n i++\n return x0 > sick.x || x1 < sick.x || y0 > sick.y || y1 < sick.y\n })\n return i\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":394,"value":"//sim.stop()","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":146,"value":"initialData = () => {\n const initialData = []\n \n for (let i = 0; i < params.N; i++ ) {\n \n const vx = (Math.random() - 0.5)\n const vy = (Math.random() - 0.5)\n \n const norm = Math.sqrt(vx*vx + vy*vy)\n\n const p = {\n id: `p${i}`,\n r: params.r,\n x: params.r + Math.random() * (params.width - params.r),\n y: params.r + Math.random() * (params.height - params.r),\n vx: params.initSpeed * vx / norm,\n vy: params.initSpeed * vy / norm,\n infected: i === 0 ? true : false,\n s: norm\n }\n \n initialData.push(p)\n const s = d3.select('#sim')\n \n const nodes = s.selectAll('circle')\n .data(initialData)\n .enter()\n .append('circle')\n .attr('id', (d, i) => i) \n .attr('cx', d => d.x)\n .attr('cy', d => d.y)\n .attr('r', d => d.r)\n .style('fill', d => d.infected ? 'red' : 'black')\n \n }\n return initialData\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":644,"value":"items = initialData()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":9,"value":"$34","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":4,"value":"d3 = require('d3@5', 'd3-force-bounce')","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W35","stdlib":"1","titling":"auto"}} 33:"$32:body"