chart = {
const svg = d3.create("svg")
.attr("viewBox", [-width / 2, -height / 2, width, height]);
const simulation = d3.forceSimulation()
.force("charge", d3.forceManyBody().strength(-3000))
.force("link", d3.forceLink().id(d => d.id).distance(20))
.force("x", d3.forceX())
.force("y", d3.forceY())
.on("tick", ticked);
let link = svg.append("g")
.attr("stroke", "#000")
.attr("stroke-width", 1.5)
.selectAll("line");
let node = svg.append("g")
.attr("stroke", "#fff")
.attr("stroke-width", 1.5)
.selectAll("circle")
// lets the user drag around nodes
.call(drag(simulation));
function ticked() {
node.attr("cx", d => d.x)
.attr("cy", d => d.y)
.attr("fill", d => color(d.id))
link.attr("x1", d => d.source.x)
.attr("y1", d => d.source.y)
.attr("x2", d => d.target.x)
.attr("y2", d => d.target.y);
}
// Terminate the force layout when this cell re-runs.
invalidation.then(() => simulation.stop());
return Object.assign(svg.node(), {
update({nodes, links}) {
// Make a shallow copy to protect against mutation, while
// recycling old nodes to preserve position and velocity.
const old = new Map(node.data().map(d => [d.id, d]));
nodes = nodes.map(d => Object.assign(old.get(d.id) || {}, d));
links = links.map(d => Object.assign({}, d));
node = node
.data(nodes, d => d.id)
.join(enter => enter.append("circle")
.attr("r", 20)
.attr("fill", d => color(d)))
.call(drag(simulation));
link = link
.data(links, d => [d.source, d.target])
.join("line");
simulation.nodes(nodes);
simulation.force("link").links(links);
simulation.alpha(1).restart();
}
});
}
update = chart.update(graph)
graph1 = ({
nodes: [
{id: 1},
{id: 2},
{id: 3},
{id: 4},
{id: 5},
{id: 6}
],
links: [
{source: 1, target: 5},
{source: 4, target: 5},
{source: 4, target: 6},
{source: 3, target: 2},
{source: 5, target: 2},
{source: 1, target: 2},
{source: 3, target: 4}
]
})
graph2 = ({
nodes: [
{id: 1},
{id: 2},
{id: 3},
{id: 4}
],
links: [
{source: 3, target: 2},
{source: 1, target: 2},
{source: 3, target: 4},
{source: 2, target: 4},
]
})
graph3 = ({
nodes: [
{id: "a"},
{id: "b"}
],
links: [
{source: "a", target: "b"}
]
})
height = 600
color = d3.scaleOrdinal(d3.schemeTableau10)
drag = simulation => {
function dragstarted(event) {
if (!event.active) simulation.alphaTarget(0.3).restart();
event.subject.fx = event.subject.x;
event.subject.fy = event.subject.y;
}
function dragged(event) {
event.subject.fx = event.x;
event.subject.fy = event.y;
}
function dragended(event) {
if (!event.active) simulation.alphaTarget(0);
event.subject.fx = null;
event.subject.fy = null;
}
return d3.drag()
.on("start", dragstarted)
.on("drag", dragged)
.on("end", dragended);
}
d3 = require("d3@6")
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
