chart = {
const height = 600;
const scale = d3.scaleOrdinal(d3.schemeCategory10);
const links = data.links.map(d => Object.create(d));
const nodes = data.nodes.map(d => Object.create(d));
const simulation = d3.forceSimulation(nodes)
.force("link", d3.forceLink(links).id(d => d.id).distance(200).strength(0.1))
.force("charge", d3.forceManyBody().strength(-50))
.force("center", d3.forceCenter(width / 2, height / 2));
const svg = d3.create("svg")
.attr("viewBox", [0, 0, width, height]);
const g = svg.append("g");
function zoomed() {
g.attr("transform", d3.event.transform);
}
const zoom = d3.zoom()
.scaleExtent([-40, 40])
.on("zoom", zoomed);
svg.call(zoom);
function dragstarted(d) {
if (!d3.event.active) simulation.alphaTarget(0.3).restart();
d.fx = d.x;
d.fy = d.y;
}
function dragged(d) {
d.fx = d3.event.x;
d.fy = d3.event.y;
}
function dragended(d) {
if (!d3.event.active) simulation.alphaTarget(0);
d.fx = null;
d.fy = null;
}
function drag(simulation) {
return d3.drag()
.on("start", dragstarted)
.on("drag", dragged)
.on("end", dragended);
}
const link = g.append("g")
.attr("stroke", "#999")
.attr("stroke-opacity", 0.6)
.selectAll("line")
.data(links)
.join("line")
.attr("stroke-width", d => Math.sqrt(d.value));
const node = g.append("g")
.selectAll(".node")
.data(nodes)
.join("g")
.attr('class', 'node')
.call(drag(simulation));
node.append('circle')
.attr("r", 5)
.attr("fill", d => scale(d.group));
node.append("text")
.text(d => d.id)
.style('fill', '#000')
.style('font-size', '12px')
.attr('x', 6)
.attr('y', 3);
node.append("title")
.text(d => d.text);
simulation.on("tick", () => {
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);
node
.attr("transform", d => `translate(${d.x}, ${d.y})`);
});
invalidation.then(() => simulation.stop());
return svg.node();
}