This randomly-generated tree is positioned using a force simulation.
Last active
June 10, 2024 11:28
-
-
Save mbostock/95aa92e2f4e8345aaa55a4a94d41ce37 to your computer and use it in GitHub Desktop.
Force-Directed Tree
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| license: gpl-3.0 | |
| height: 960 | |
| redirect: https://observablehq.com/@d3/force-directed-tree |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <canvas width="960" height="960"></canvas> | |
| <script src="https://d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| var nodes = d3.range(1000).map(function(i) { | |
| return { | |
| index: i | |
| }; | |
| }); | |
| var links = d3.range(nodes.length - 1).map(function(i) { | |
| return { | |
| source: Math.floor(Math.sqrt(i)), | |
| target: i + 1 | |
| }; | |
| }); | |
| var simulation = d3.forceSimulation(nodes) | |
| .force("charge", d3.forceManyBody()) | |
| .force("link", d3.forceLink(links).distance(20).strength(1)) | |
| .force("x", d3.forceX()) | |
| .force("y", d3.forceY()) | |
| .on("tick", ticked); | |
| var canvas = document.querySelector("canvas"), | |
| context = canvas.getContext("2d"), | |
| width = canvas.width, | |
| height = canvas.height; | |
| d3.select(canvas) | |
| .call(d3.drag() | |
| .container(canvas) | |
| .subject(dragsubject) | |
| .on("start", dragstarted) | |
| .on("drag", dragged) | |
| .on("end", dragended)); | |
| function ticked() { | |
| context.clearRect(0, 0, width, height); | |
| context.save(); | |
| context.translate(width / 2, height / 2); | |
| context.beginPath(); | |
| links.forEach(drawLink); | |
| context.strokeStyle = "#aaa"; | |
| context.stroke(); | |
| context.beginPath(); | |
| nodes.forEach(drawNode); | |
| context.fill(); | |
| context.strokeStyle = "#fff"; | |
| context.stroke(); | |
| context.restore(); | |
| } | |
| function dragsubject() { | |
| return simulation.find(d3.event.x - width / 2, d3.event.y - height / 2); | |
| } | |
| function dragstarted() { | |
| if (!d3.event.active) simulation.alphaTarget(0.3).restart(); | |
| d3.event.subject.fx = d3.event.subject.x; | |
| d3.event.subject.fy = d3.event.subject.y; | |
| } | |
| function dragged() { | |
| d3.event.subject.fx = d3.event.x; | |
| d3.event.subject.fy = d3.event.y; | |
| } | |
| function dragended() { | |
| if (!d3.event.active) simulation.alphaTarget(0); | |
| d3.event.subject.fx = null; | |
| d3.event.subject.fy = null; | |
| } | |
| function drawLink(d) { | |
| context.moveTo(d.source.x, d.source.y); | |
| context.lineTo(d.target.x, d.target.y); | |
| } | |
| function drawNode(d) { | |
| context.moveTo(d.x + 3, d.y); | |
| context.arc(d.x, d.y, 3, 0, 2 * Math.PI); | |
| } | |
| </script> |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment